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25 April 2014, Volume 35 Issue 8
Application of Immunological Techniques in Detection of Food Allergens: A Review
HU Xiao-fei1, WANG Yao2, DENG Rui-guang1, ZHANG Gai-ping1,3,*
2014, 35(8):  1-5.  doi:10.7506/spkx1002-6630-201408001
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The allergic reactions caused by food allergens are threatening human health and life. Currently, allergy
information on the packaging of food products is imperfect. Thus, development of technologies to detect food allergens is
critical to prevent allergy-causing foods from entering into circulation and to reduce the occurrence of allergic incidents.
This review summarizes recent applications of immunological technologies in the detection of food allergens, and discusses
future prospects in this field.

Recent Development and Application of Electrochemical Nanometer Immunosensors in Food Detection
LU Ding-qiang, PANG Guang-chang*
2014, 35(8):  6-10.  doi:10.7506/spkx1002-6630-201408002
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Electrochemical nanometer immunosensor has the characteristics of simple operation, accuracy, high sensitivity
and good selectivity, where biological sensing chips are used to detect the interaction between antigen and antibody. It has
a wide range of applications in the fields of medicine, food, environmental monitoring, drug screening and life science. In
this paper, we compare electrochemical nanometer immunosensor with instrumental analysis, immunological detection,
polymerase chain reaction (PCR)-based molecular biology detection techniques and surface plasmon resonance (SPR)- and
biolayer interferometry (BLI)-based detection techniques for their advantages and drawbacks. We also discusse the two
key issues electrochemical nanometer immunosensor itself is facing: immune binding signal amplification processing and
commercial application. Finally, we overview the current applications of nanomaterial in the immunosensor and those of
electrochemical nanometer immunosensor in food detection, and discuss its future prospects in this area.

Historical Development and Present Situation of Detection Methods for Amanita Peptide Toxins
CHEN Zuo-hong1, HU Jin-song1,2
2014, 35(8):  11-16.  doi:10.7506/spkx1002-6630-201408003
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Fatal mushroom poisoning incidents occur annually all over the world and it is one of the important causes of
human death due to food poisoning in China. The peptide toxins in some Amanita species are mainly responsible for the
mortality. Rapid and effective detection of toxins from samples of poisonous mushroom, food residue, vomit, blood and
urine has important significance for the identification of toxic sources and the development of targeted therapies. This paper
reviews the historical development and present situation of detection methods for Amanita peptide toxins including chemical
color reaction, biochemical, physical and chromatographic methods. The application and prospects of these detection
methods in China are also discussed.

Suggestions on Performance Evaluation of Food Traceability System Based on US Pilot Project Reports
LI Jia-jie, WANG Ning, CUI Yan-yan, WANG Zhi-gang
2014, 35(8):  17-22.  doi:10.7506/spkx1002-6630-201408004
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Food traceability system has become one of the most important methods to rapidly identify the key causes of
problems and ensure food safety, and has been greatly developed all over the world. However, how to maintain the high
efficiency of a food traceability system is another significant issue. In this paper, we analyze a recent report from US FDA
in 2012 with regard to performance evaluation of food traceability system along the food supply system, and discuss how
research methods and recommendations from the report could provide any references and suggestions for our future work.

RASFF-Based Empirical Analysis of the Safety of Chinese Food Products Exported to the European Union
MIAO Tian-shun1, ZHOU Qing2, ZHOU Qing-jie1,*
2014, 35(8):  23-28.  doi:10.7506/spkx1002-6630-201408005
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The safety of Chinese exported food products plays a significant role in establishing a positive world-wide
reputation of products made in China, and it is also critical for Chinese food products to enter the international market
place. Based on the rapid alert system for food and feed (RASFF) database, an exchange information tool on risk measures
related to food and feed controls, this paper analyzes 2 409 notifications on Chinese exported food products for food safety
issues between 2008 and 2012 in terms of notifications types, notification classifications, notification bases, EU member
states, product categories, product origins and hazard categories. The number of notifications on food products from China
accounts for a high proportion of the total number of notifications (14.47%). Border rejection accounts for the largest
proportion among all types of notifications. Italy, Germany and UK are the top three member states that have made the most
notifications. The top three most notified product categories are food contact materials, nuts, nut products and seeds, and
cereals and bakery products. The major risks causing notifications are migration, mycotoxins and heavy metals. This paper
intends to present a general picture of the safety of Chinese food products exported to the European Union (EU) and provide
some suggestions to food safety researchers and administers.

Overview of Assessment Techniques for Sensory Panel and Panelist Performance
SHI Bo-lin1, ZHAO Lei1,*, WANG Hou-yin1, ZHI Rui-cong1, HUAN Chang2, YUN Zhan-you3, SU Yu-fang3
2014, 35(8):  29-35.  doi:10.7506/spkx1002-6630-201408006
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In sensory evaluation, panels and panelists are used as instruments that are the key tool to obtain reliable sensory
data. Assessment techniques for their performance can provide an important approach for managing them effectively. In this
paper, the validity and reliability are used as the main indexes for performance assessment, which have reached a plateau of
research since the beginning of the 21st century. More than 85% of the research papers have been reported in the top journals
in sensory science, such as Food Quality and Preference and Journal of Sensory Studies. Especially, the majority of the
research reports come from the USA and Europe and have tended to be frequent and mature in assessing the performance
of descriptive sensory panels-panelists. The various methods include univariate or multivariate variance analysis, and
multivariate statistical methods such as principal component analysis (PCA), generalized procrustes analysis (GPA), etc. At
the same time, softwares such as PanelCheck, Compusense Five, and so on have been developed, while the International
Organization for Standardization and the American Society for Testing and Materials are also formulating the relevant
standards on quantitative descriptive analysis. By contrast, relatively insufficient research has been done on performance
assessment in ranking and discrimination sensory panels-panelists. Six key research contents are proposed for future study.
They include the number and property of sample, the form of data presentation, the design of sensory experiment, expected
value and confidence interval, and the selection of sensory analysis methods and statistical methods. This paper will be
helpful to establish the unified and systemic framework for assessing performance in panels and panelists.

Immunochromatographic Strip Technology and Its Application in Food Safety Detection
LI Jian-wu1, SONG Chun-mei1, LIU Fang2, WU Shu-yan1, LI Hao-lin3, LIU Cheng3, QIU Shi1, ZENG Hai-juan1, WU Man1, LIU Qing1,*
2014, 35(8):  36-41.  doi:10.7506/spkx1002-6630-201408007
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Immunochromatographic strip has been popularly used in clinical diagnosis and other areas because of its ease
operation, less time-consuming, stable results, relative inexpensiveness and applicability for in situ and domestic testing. As food
safety incidents have occurred frequently in recent years, this technology has been widely used in rapid food safety testing. In this
paper, we overview immunochromatographic strip technology and its recent applications, and discuss its future prospects. We
expect that this review will provide useful references for the future development and application of this technology.

Advances in Detection Methods for Nitrate and Nitrite in Vegetables
ZHAO Jing1,2, WANG Na3, FENG Xu-qiao1,3,*, ZHAO Hong-xia3, HUANG Xiao-jie3,4
2014, 35(8):  42-49.  doi:10.7506/spkx1002-6630-201408008
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Nitrate and nitrite get into human body mainly through vegetables. Nitrite is a kind of toxic substance that can produce
carcinogenic nitrosamines. The major methods currently available for the detection of nitrate and nitrite in vegetables include
spectroscopy, chromatography and rapid assays. This paper, beginning with a comparative introduction to these methods, reviews
recent advances in detection methods for nitrate and nitrite in vegetables and discusses future prospects.

Detection of Salmonella by Electrochemical Method Based on Au/SiO2 Signal Amplification
SONG Liang-jing, MA Xiao-yuan, DUAN Nuo, WU Shi-jia, WANG Zhou-ping*
2014, 35(8):  50-56.  doi:10.7506/spkx1002-6630-201408009
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Purpose: To establish a detection method with high sensitivity for Salmonella by cyclic voltammetry based on
Au/SiO2 signal amplification. Methods: The capture DNA and the display DNA, which are complementary with the target DNA were
modified onto the surface of indium tin oxide (ITO) electrode and the surface of Au/SiO2 nanoparticles. As results, capture probe and
display probe were constructed. A “sandwich” structure was constructed by capture DNA-target DNA-display DNA when Salmonella
target DNA was added into the system. As the content of Au/SiO2 was positively correlated with the concentration of the target DNA,
the peak current value of fully modified ITO could be changed by varying the concentration of the target DNA, so as to achieve the
purpose of detection. Results: Under the optimal conditions, the method showed a good linear relationship when the concentration
of target DNA was in the range of 10-11 to 10-7 mol/L, the linear regression equation was y = -0.000 3x + 0.000 1 (R2 = 0.998 9), and
the lowest limit of detection (LOD) was 6 pmol/L. And it showed a good linear relationship when the concentration of Salmonella
was in the range of 50 to 7 910 CFU/mL, the linear regression equation was y = -1.6×10-7x + 0.003 2 (R2 = 0.994 0), and the lowest
LOD was 35 CFU/mL. Conclusions: The specificity and spiked recovery experiments proved that this method could be used for the
detection of actual samples.

Determination of Anthocyanin Content in Grape Skins Using Hyperspectral Imaging Technique and Successive Projections Algorithm
WU Di1, NING Ji-feng1,*, LIU Xu2,3,*, LIANG Man2, YANG Shu-qin4, ZHANG Zhen-wen2
2014, 35(8):  57-61.  doi:10.7506/spkx1002-6630-201408010
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This work aimed to determine the anthocyanin content in grape skins based on hyperspectral imaging
technology in combination with successive projections algorithm (SPA). Cabernet Sauvignon (Vitis vinifera L.) grape berries
from Shaanxi province were used as experimental materials. Hyperspectral images of 60 groups of grape samples were
collected by near infrared hyperspectral camera and the anthocyanin contents in these samples were detected. Multiplicative
scatter correction was used to improve the signal-to-noise ratio (SNR). Moreover, SPA was applied for the extraction of
effective wavelengths (EWs), which showed least collinearity and redundancies in the spectral data. The selected effective
wavelengths were used as the inputs of multiple linear regression (MLR), partial least squares (PLS) and BP neural network
(BPNN). Then SPA-MLR, SPA-PLS and SPA-BPNN models were developed and compared with full-spectrum-PLS
model. It was shown that SPA-MLR, SPA-PLS and SPA-BPNN models were better than full-spectrum-PLS model. The
best performance was achieved by SPA-PLS model with Rp of 0.900 0 and RMSEP of 0.550 6. These results indicate that
anthocyanin contents in grape skins could be measured effectively by using near infrared hyperspectral imaging.

Determination of Mercury and Arsenic in Foods by Hydride Generation-High Resolution Continuum Source Atomic Absorption Spectrometry
REN Ting, CAO Jun, ZHAO Li-jiao*, ZHONG Ru-gang
2014, 35(8):  62-66.  doi:10.7506/spkx1002-6630-201408011
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Hydride generation-high resolution continuum source atomic absorption spectrometry (HG-HRCS-AAS) has been
employed in this work to determine mercury (Hg) and arsenic (As) levels in 22 kind of foods including cereals, vegetables,
beverage, aquatic products and dairy foods. The methods for sample pretreatment and quantitative analysis were established. The
limit of detection (LOD) was 0.067 μg/L for Hg and 0.088 μg/L for As. The recoveries of Hg and As from spiked samples were
97.0%–104.2% and 96.4%–105.1%, with RSD of 0.8%–4.7% and 3.5%–4.9% (n = 6), respectively. The results showed that the
content of Hg was higher in whole wheat flour, coffee and aquatic products samples and was detectable in fruit juice samples. The
content of As in Chinese leek, coiliaspp, shellfish and shrimp was higher than that in other tested foods.

Rapid Discrimination of Edible Oils by Synchronous Fluorescence Spectroscopy
MAO Li-xin, GUO Jian-rong, WU Xu, GUO Jie-li
2014, 35(8):  67-71.  doi:10.7506/spkx1002-6630-201408012
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This paper describes a comparative analysis of the total synchronous fluorescence (TSyF) spectra of seabuckthorn
fruit oil, seabuckthorn seed oil, walnut oil, rapeseed oil, sesame oil and linseed oil. TSyF spectra were acquired by varying
the excitation wavelength in the region of 250–720 nm. Six kinds of vegetable oils can be discriminated from each other
based on their TSyF spectra. The maximum excitation wavelengths of seabuckthorn fruit oil, seabuckthorn seed oil, walnut
oil, rapeseed oil, sesame oil and linseed oil were 315–450, 520–650, 315–490, 300–500, 300–550 and 300–490 nm,
respectively. The principal component analysis was used to successfully discriminate among these vegetable oils. Thus, this
study has established a fast and simple technique for the detection of seabuckthorn fruit oil, sea buckthorn seed oil, walnut
oil, rapeseed oil and sesame oil and linseed oil.

Analysis of Volatile Compounds in Jingzhi Baigan Liquor by Liquid-liquid Extraction (LLE) and Gas Chromatography-Mass Spectrometry (GC-MS)
WU Ji-hong, HUANG Ming-quan*, SUN Bao-guo, ZHENG Fu-ping, SUN Jin-yuan
2014, 35(8):  72-75.  doi:10.7506/spkx1002-6630-201408013
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Volatile compounds of Jingzhi Baigan liquor were analyzed by liquid-liquid extraction and gas chromatographymass
spectrometry and identified by mass spectral library searching and comparison of retention indexes. Different
compounds were extracted by using different kinds of organic solvents with various polarities. The results showed that 30
compounds were identified in n-pentane extract compared to 29 compounds in ethyl ether extract and 35 compounds in
dichloromethane extract. In total, 65 compounds were extracted with three organic solvents including 9 alcohols, 19 esters,
11 acids, 14 alkanes, 3 aromatics, 3 furans, 3 aldehydes, 1ketones, 1 nitrogenous compound and 1 sulfocompound.

Determination of Paclobutrazol Residues in Fruits and Vegetables by QuEChERS-High Performance Liquid Chromatography-Triple Quadrupole Tandem Mass Spectrometry
SUN Xing, DING Yue, WANG Jia-lei, WANG Dong-lan, SHEN Yan, LIU Xian-jin*
2014, 35(8):  76-79.  doi:10.7506/spkx1002-6630-201408014
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A method was developed for the determination of paclobutrazol residues in fruits and vegetables by using
QuEChERS-high performance liquid chromatography-triple quadrupole tandem mass spectrometry (HPLC-MS-MS).
Paclobutrazol residues in fruit samples were extracted with acetonitrile, dehydrated with sodium chloride and anhydrous
magnesium sulfate, cleaned up by dispersive solid phase extraction on primary secondary amine and graphitized carbon
black, and detected by HPLC-MS-MS under a multiple reaction-monitoring mode. The qualitative results were obtained
based on the characteristic m/z 294.2/70.0 and m/z 294.2/125.0, and the quantitative results were based on the characteristic
m/z 294.2/70.0. The recoveries of paclobutrazol were in the range from 79.6% to 94.9% at three spiked levels of 0.05, 0.5
and 1 mg/kg from five fruits and vegetable matrixes (pear, apple, peach, tomato and cucumber), with relative standard
deviations (RSDs) between 3.6% and 11.4%, and the limits of detection were 0.4, 0.5, 0.4, 0.4 and 0.5 μg/kg, respectively.
The method is simple, quick, safe, reproducible and applicable to detect and confirm paclobutrazol residues in fruit and
vegetable samples.

Optimization of Extraction of Volatile Oil from Allium macrostemon Bunge and Chemical Composition Analysis by Gas Chromatography-Mass Spectrometry
HUANG Fang, ZHOU Hong, YU Shan-shan
2014, 35(8):  80-84.  doi:10.7506/spkx1002-6630-201408015
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The volatile oil from the bulbs of Allium macrostemon Bunge was extracted by steam distillation with soaking in
hot water and ultrasonic pretreatment. Based on single factor experiments, the yield of volatile oil was selected as response
value and the optimum extraction process was determined through response surface methodology. The chemical constituents
of the volatile oil were analyzed by gas chromatography mass spectrometry (GC-MS). The results showed that the optimal
extraction conditions were soaking in 40 ℃ water with a liquid-to-solid ratio of 4.40:1 (mL/g), ultrasonic pretreatment for
30 min and distillation for 2.2 h. Under these conditions, the yield of volatile oil was 1.030%. Totally 17 compounds were
detected and 14 of them were identified by GC-MS in the extracted volatile oil, together accounting for 93.46% of the total
amount of extracted compounds based on peak area normalization.

A Real-Time PCR to Detect Horse and Donkey Ingredients in Donkey Hide Glue
WU Ya-jun, WANG Bin, LIU Ming-chang, HAN Jian-xun, LI Xin-shi, CHEN Ying*
2014, 35(8):  85-88.  doi:10.7506/spkx1002-6630-201408016
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In this study, we established a highly specific and sensitive real-time polymerase chain reaction (PCR) method to
detect horse and donkey components in donkey hide glue. The mitochondrial tRNA-Thr gene of horse and the mitochondrial
D-loop region of donkey were selected as target sequences for the designing of specific primers. In conventional and realtime
PCR assays, horse and donkey ingredients could be specifically detected using both primer pairs.

Detection of Freshness Attributes of Yao Meat Based on Hyperspectral Imaging Technique
ZOU Xiao-bo, LI Zhi-hua, SHI Ji-yong, HUANG Xiao-wei
2014, 35(8):  89-93.  doi:10.7506/spkx1002-6630-201408017
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Total volatile basic nitrogen (TVB-N) content of Yao meat stored at 4 ℃ after the package was opened was
measured every 24 h for 8 days, and reflectance spectra were collected from the hyperspectral scattering images (HIS) in the
range of 430 to 960 nm. After pre-processed by standard normal variate transformation (SNV) method, prediction models
for TVB-N content in Yao meat were established by partial least squares (PLS) method, interval partial least squares (iPLS)
method, backward interval partial least squares (biPLS) method and synergy siPLS method separately. Experimental results
showed that the siPLS model could predict Yao meat TVB-N with correlation coefficient (Rp) of 0.854 8 and root mean
squared error of prediction (RMSEP) of 2.47, which was the best of the four models, and 430–461, 555–586 and 929–960
nm were the selected wavelength ranges. The overall prediction accuracy of the siPLS model for Yao meat freshness could
reach up to 87.5%. The present study shows that HIS technique is feasible for fast and non-destructive detection of Yao meat
freshness attributes.

stx Genotypes and Virulence Characteristics of E. coli O157:H7 Strains Isolated from Meat Products Commercialized in Wuhan
ZHENG Dong-dong1, BI Wang-lai1, WANG Hong-xun2, LIU Zhi-guo1, DING Hong-bo1, LI Rui1,3,*
2014, 35(8):  94-98.  doi:10.7506/spkx1002-6630-201408018
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A total of 117 raw meat samples were collected from 22 markets in Wuhan, China and four E. coli O157:H7
strains were isolated from these meat samples, which were positive for stx, hly and eae genes. The stx variant genes were
further subtyped by polymerase chain reaction (PCR) using sequence-specific primers targeting each stx variant. Three
isolates were found to carry both stx1 and stx2 genes, and the prevalent stx genotypes were stx1a and stx2a. One isolate EC
5.11 was found to carry only stx2 gene but it could not be subtyped by PCR assay. The entire stx2 gene was then amplified from
EC 5.11, cloned into a vector and sequenced. Sequencing data showed that the stx2 gene of EC5.11 was 100% identical to the
published sequences of stx2c. The production of Shiga toxin from the four isolates was confirmed by Vero cell toxicity assay.

On-site Electrochemical Detection of Clenbuterol Based on Mini-Screen Printed Electrodes
LIANG Hua1, SONG Wei2, XU Dan-ke2, LIU Ying3, ZHONG Wen-ying1,*
2014, 35(8):  99-104.  doi:10.7506/spkx1002-6630-201408019
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An electrochemical sensing method for the detection of clenbuterol (CLB) was developed based on miniscreen
printed electrodes and 96-well microtiter plate. Clenbuterol residues were indirectly detected by combined use of
indirect competitive immunoreaction and chronoamperometry. The immune reaction and enzymatic reaction conditions
were investigated. Under the optimized conditions, the results showed that the electrochemical immunosensor produced a
linear range of 0.025–2.0 μg/L with a correlation coefficient of 0.999 2. The analytical results of CLB residues in pork and
swine urine samples were consistent with those obtained with an enzyme-linked immunosorbent assay (ELISA) plate. The
detection limits for pork and swine urine samples were 0.18 μg/L and 0.05 μg/L, respectively, showing a decrease of one
order of magnitude in comparison with those of ELISA.

Establishment and Application of an Analytical Database for Cronobacter spp. by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry
ZHAO Gui-ming, LIU Yang, CHEN Ying*, YANG Hai-rong, ZHAO Yong-sheng, WANG Ping
2014, 35(8):  105-110.  doi:10.7506/spkx1002-6630-201408020
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The purpose of this study was to establish an analytical database for high throughput identification and subtyping
of 8 species of Cronobacter spp. by a matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDITOF-
MS) method. Under the optimized culture and sample treatment conditions by using the established MALDI-TOFMS
protein fingerprint acquisition parameters, the acquired characteristic protein mass spectrometric profiles of 8 reference
strains were used to build a MALDI-TOF-MS database with Biotyper software, and the accuracy of the database was
validated by comparison with data from related enterobacteriaceae strains and isolates of the genus Cronobacter. The
MALDI-TOF-MS database was applied to analyze 135 isolates of Cronobacter spp. with an identification score no smaller
than 2.0, which reached the requirement for identification at the species level. Further subtyping was achieved by cluster
analysis. This MALDI-TOF-MS database may provide a new approach for high throughput identification and subtyping of
Cronobacter strains.

Determination of Penicillin G in Milk by Gold Nanoparticles Based Electrochemical Immunosensor
LI Jian-long, PAN Dao-dong*, ZHU Hao-jia, GU Yuan-yuan, ZHAO Zi-wei, ZHU Shan-shan
2014, 35(8):  111-114.  doi:10.7506/spkx1002-6630-201408021
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An amperometric immunosensor was fabricated by co-immobilizing penicillin G polyclonal antibody (Ab*)
on the surface of a gold nanoparticle modified glassy carbon electrode through electrostatic adsorption. A highly sensitive
one-step direct electrochemical immunoassay was established due to the strong adsorption and conductive capacity of gold
nanoparticles, thus raising the amount of fixed penicillin G antibody and electrochemical sensitivity. Under optimized
conditions, the current response of the sensor showed a good linear relationship with logarithmic penicillin concentration in
the range of 0.04-40.00 ng/mL with a correlation coefficient of 0.988 4 and the detection limit was 2.49 ng/mL. The method
was able to detect penicillin in milk successfully.

Separation and Identification of Volatile Flavors of High-Temperature Intensified Ham by Gas Chromatography-Mass Spectrometry Coupled with Head Space Purge and Trap
TANG Jing, ZHANG Ying-yang, WU Hai-zhou, CHEN Xiao, ZHANG Jian-hao*
2014, 35(8):  115-120.  doi:10.7506/spkx1002-6630-201408022
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Volatile flavor compounds from high-temperature intensified ham were extracted by purge and trap and analyzed
by gas chromatographic-mass spectrometry (GC-MS). Ham samples were collected at five different stages: the end of salting,
the middle stage of aging, the end of aging, the middle stage of post-aging and the end of post-aging. The results showed that
the composition of volatile compounds was similar between high-temperature intensified ham and traditional dry-cured ham,
but the contents of some volatile compounds showed a significant difference between them, especially for acids and esters.
Indene, dibenzofuran and 2,3-dimethyl-naphthalene were first detected in high-temperature intensified ham. Totally 11 key
flavor compounds were identified by relative odor activity value (ROAV), including 3-methyl-butanal, dimethyl-disulfide,
2-nonenal, 2-octenal, octanal, nonanal, heptanal, pentanal, hexanal, 1-octen-3-ol and 1-heptanol.

Determination of Cadmium, Lead and Copper in Milk by Hg-Plated Anodic Stripping Voltammetry
ZHU Hao-jia, PAN Dao-dong*, GU Yuan-yuan, LI Jian-long, ZHAO Zi-wei, DING Lin
2014, 35(8):  121-124.  doi:10.7506/spkx1002-6630-201408023
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A method for the simultaneous determination of cadmium, lead and copper in milk was established using Hg-plated
anodic stripping voltammetry. Under optimized test conditions, the peak potentials of cadmium, lead and copper were -0.70,
-0.52 and -0.08 V, respectively. The linear domain ranges were 0.1–40, 1–80 and 0.5–100 μg/L, respectively, and the limits of
detection were 0.06, 0.3 and 0.1 μg/L, respectively. The spiked recoveries of cadmium, lead and copper were 99.57%, 101.3%
and 98.00%, respectively, with RSDs (n = 5) of 4.0%, 2.9% and 2.7%, respectively. There was no significant difference
(P > 0.05) between the results from simultaneous anodic stripping voltammetry and atomic absorption spectroscopy (AAS).
This voltammetric method has the advantages of rapidity, simplicity and accuracy, and can be used for the simultaneous
determination of cadmium, lead and copper in milk.

Analysis of Volatile Compounds in Embryo of Dictyophora indusiata (Vent. Pers.) Fisch Using Headspace-Solid Phase Microextraction Combined with GC-MS
ZHENG Jiong1,2, LI Ting-ting1, SONG Jia-xin1, KAN Jian-quan1,2,*
2014, 35(8):  125-128.  doi:10.7506/spkx1002-6630-201408024
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The volatile compounds in the dried embryo of Dictyophora indusiata (Vent. Pers.) Fisch were analyzed by
headspace-solid phase microextraction (HS-SPME) combined with GC-MS. Results indicated that 65 kinds of volatile
compounds were identified, including 20 hydrocarbons, 12 esters, 11 ketones, 9 aldehydes, 6 alcohols, 4 acids and 3 aromatic
compounds. The major volatile components in Dictyophora indusiata (Vent. Pers.) Fisch were β-patchoulene (12.41%),
α-chamigrene (9.64%), α-cedrene (9.57%), β-cedrene (7.58%), α-bulnesene (6.72%), α-bisabolene (4.44%), β-chamigrene
(4.38%), isolongifolen-5-one (3.86%) and γ-muurolene (3.74%).

Separation and Determination of Five Kinds of Polyphenolic Compounds in Tea by Capillary Electrophoresis
MA Xiao-nian1,2, SHAO Ya-ting1, LI Fei1, XIONG Jie1, CAO Qiu-e1,*
2014, 35(8):  129-132.  doi:10.7506/spkx1002-6630-201408025
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Objective: To develop a method for simultaneous separation and determination of catechin, epicatechin, quercitin,
kaempferol and myricetin in tea. Methods: High performance capillary zone electrophoresis was used. Results: Catechin,
epicatechin, quercitin, kaempferol and myricetin could be effectively separated and determined within 14 min in a running
buffer solution (pH 9.11) containing 10 mmol/L Na2B4O7, 5 mmol/L β-CD and 8% (v/v) acetonitrile with the applied voltage
of 20 kV, capillary temperature of 25 ℃ and detector wavelength of 200 nm. The relative standard deviation and recovery
of the proposed method for these five compounds in tea were below 4.0% and in the range of 95%-105.6%, respectively.
Conclusion: This method possesses the advantages of simple operation, rapid determination, high reproducibility and wide
detection range. It can be used for the determination of catechin, epicatechin, quercitin, kaempferol and myricetin in tea.

Rapid Detection of Kudzu Starch Adulteration by Near-Infrared Diffuse Reflectance Spectroscopy
CHEN Jia1, LIU Jia1, MA Ya-qin1, ZHU Shi-ping2, ZHAO Guo-hua1,3,*
2014, 35(8):  133-136.  doi:10.7506/spkx1002-6630-201408026
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Near-infrared diffuse reflectance (NIDR) spectroscopy combined with chemometric techniques was developed
for rapid detection of kudzu starch adulterated with cheaper starches (potato and sweet potato starch). Principal component
regression (PCR) and partial least squares regression (PLSR) were used to build and evaluate calibration models by different
pre-treatment methods and at different wavelength bands . The PLS calibration model based on wavelength bands of 962–
1 389 nm and spectral pre-treatment by the standard normal variate transformation (SNV) showed an excellent prediction
accuracy. The external validation set provided a coefficient of determination (R2), root mean square error of prediction
(RMSEP) and relative prediction deviation (RPD) of 0.994 5, 2.298 7% and 13.56, respectively. The average recovery rate
was 99.89% (n = 9) with a relative standard deviation (RSD) of 2.96%. The results indicate that NIDR spectroscopy can be
used as an efficient way to detect kudzu starch adulterated with cheaper starches.

Application of High-Speed Countercurrent Chromatography in Purification of Chemical Constituents from Green Tea
WANG Wei, LIN Nan, LE Sheng-feng, WANG Tan, ZHOU Xiao-jing, ZHAO Xin-ying, DU Ning, ZHANG Jing-hua
2014, 35(8):  137-141.  doi:10.7506/spkx1002-6630-201408027
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Chemical constituents were separated from green tea by high-speed counter-current chromatography (HSCCC).
Based on stagewise extraction and optimization of solvent systems, the separation of active ingredients by HSCCC was
developed. Eight compounds including CFA, EGC, EC, C, EGCG, GCG, ECG and GA with high purity were obtained.
The purity of each compound was up to 99.5%, 97.2%, 98.2%, 97.6%, 98.8%, 99.1%, 99.2% and 98.8%, respectively. The
method is of high separation efficiency, simple operation, and great importance for the purification of components from
green tea in the food and medical fields.

Determination of Formaldehyde Content in Smoked Meat by GC-MS
RUI Lu-ming, PENG Zeng-qi*, WANG Min, ZHANG Lu, YAO Yao, WANG Fu-long, ZHANG Ya-wei, HUI Teng, LI Jun-ke
2014, 35(8):  142-146.  doi:10.7506/spkx1002-6630-201408028
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A method was developed for the determination of formaldehyde in smoked meat using gas chromatograph-mass
spectrometer (GC-MS). The optimal derivatization and extraction conditions were determined as the follows: derivatization
with 0.3 mL of 2,4-dinitrophenylhydrazine at 60 ℃ for 30 min, and two repeated extractions with dichloromethane. The
average recoveries at low, moderate, and high spiked levels were 79.8%, 84.0% and 89.4%, repeatability. The repeatability
expressed as relative standard deviation was 2.89%, and the detection limit was 0.50 mg/kg. The method is simple, rapid,
accurate, and sensitive and can be used for the determination of formaldehyde in smoked meat.

Determination of Total Nitrogen in Green Tea by Fourier Transform Near Infrared Spectroscopy
YANG Dan, LIU Xin*, ZHANG Ying-bin, YIN Peng
2014, 35(8):  147-151.  doi:10.7506/spkx1002-6630-201408029
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A highly accurate and stable calibration model of total nitrogen content in green tea was established based on
partial least square regression. The model demonstrated great predictive performance after the first derivative processing
and smoothing in the spectral range of 4 691–3 959 cm-1 and 5 126–4 848 cm-1. The correlation coefficient of predicted and
chemically measured values in the validation set was 0.993 9 and the RMSEP was 0.092 5%. The prediction performance
was improved by developing sub-models of total nitrogen in green tea according to different tenderness. The prediction
performance of the tenderness level 3 model was the best. The RMSEP in the validation set was the smallest, 0.037 9%,
and the correlation coefficient was 0.996 1. Thus, near infrared spectroscopy can provide a green, rapid and efficient
technique for the detection of total nitrogen in green tea and quality evaluation.

Determination of Phenolic Compounds in Proso Millet by High Performance Liquid Chromatography
LU Rong1, TIAN Qin1, SUN Nan1, QIAO Zhi-jun2, ZHANG Li-zhen1,*, NIU Wei3, SHAN Lu1, JI Pei-shuang1
2014, 35(8):  152-155.  doi:10.7506/spkx1002-6630-201408030
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The Folin-Ciocalteu method was used to assay the free phenolic content of proso millet. High performance liquid
chromatography (HPLC) was used to analyze its phenolic composition. The results showed that free phenolic content was not
significantly different among different varieties of millet bran, but significantly different (p < 0.01) in the debranned grain. Free
phenolic content was significantly different (p < 0.05) between the bran and grain from the same variety, and the bran had much
higher free phenolic content. The highest free phenolic content was found in both bran and grain from proso millet Chimi 2, with
159.22 mg gallic acid equiv/100 g bran, and 47.98 mg gallic acid equiv/100 g grain. Chlorogenic acid, syringic acid, vanillic acid,
p-coumaric acid and ferulic acid were the major phenolic acids in proso millet.

A Real-Time Polymerase Chain Reaction Method to Detect Genetically Modified Wheat Strains B73-6-1, B72-8-11b and B102-1-2
CAO Ji-juan1, XU Jun-yi 1, CAO Dong-mei1, ZHANG Pi-qiao1,2, LUAN Feng-xia3, LIU Yang1
2014, 35(8):  156-159.  doi:10.7506/spkx1002-6630-201408031
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Aim: To establish a real-time PCR method for the identification of transgenic wheat strains B73-6-1, B72-8-11b
and B102-1-2. Methods: Specific primers and probes were designed according to the flanking sequences of exogenous
fragments of transgenic wheat and wheat chromosomes. The specificity of the developed method was validated by using
it to detect a variety of other genetically modified crops and non-genetically modified wheat strains. B73-6-1 was used
to prepare 10 content gradients to test the sensitivity. Results: The primers and probes designed showed good detection
specificity for transgenic wheat strains, with its sensitivity reaching 0.01% (m/m). Conclusion: A real-time PCR method for
the identification of three genetically modified wheat strains has been established. This method is of high specificity, high
reproducibility, rapid identification and excellent accuracy for the identification of genetically modified wheat strains B73-6-1,
B72-8-11b and B102-1-2.

Detection of Enterohemorrhagic Escherichia coli O157:H7 by DPO-PCR Method
XU Yi-gang1, LI Dan-dan2, CUI Li-chun3, LIU Zhong-mei1, LI Su-long1
2014, 35(8):  160-164.  doi:10.7506/spkx1002-6630-201408032
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The aim of this study was to develop a method for the detection of enterohemorrhagic Escherichia coli O157:H7
(EHEC O157:H7) using dual-priming oligonucleotide (DPO) PCR technique. Based on DPO primer principle, a pair of
DPO primers was designed using the rfbE gene of EHEC O157:H7 as the target. Following the optimization of the reaction
system, the DPO-PCR method for the detection of EHEC O157:H7 was successfully developed with a sensitivity of
94 CFU/mL. Compared to the conventional PCR method, the DPO-PCR method was not sensitive to annealing temperature.
Thus, it was not required to repeatedly optimize primer and its annealing temperature during primer design and testing.
Moreover, the specific structure of DPO primers improved the specificity of conventional PCR method. Therefore, the
DPO-PCR method provides a new way for rapid and accurate detection of pathogenic microorganisms.

Evaluation of Uncertainty in Rhodamine B Determination in Chili Powder by HPLC
NIU Hua, NIU Zhi-rui*, FENG Lei, LU Yan-hua, MA Xue-tao, TAN Jian-lin, ZHANG Xue-zhong, FENG Jin-mei
2014, 35(8):  165-168.  doi:10.7506/spkx1002-6630-201408033
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An uncertainty evaluation model was established for evaluating the determination results of rhodamine B in chili
powder by high performance liquid chromatography (HPLC). In this paper, the key factors affecting the measurement results
during the analysis process were discussed. Meanwhile, the combined and expanded uncertainties were evaluated. During
sample preparation, the recovery of rhodamine B at the purification step by gel permeation chromatography (GPC) made the
most important contribution to the overall uncertainty. Therefore, the stability control of GPC during the purification is the
key point. The uncertainty evaluation model is practical, simple and easy to understand and valuable as a reference.

Confirmation of PCR Results for Puffer Fish Components by Restriction Endonuclease Digestion
QU Liang-miao1,2, CHEN Wen-bing1,3,*, MIAO Ting-yu1,3, SHAO Bi-ying1,3, PENG Juan1,3, JIANG Shu-xun1,3
2014, 35(8):  169-173.  doi:10.7506/spkx1002-6630-201408034
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False positive results frequently happen in PCR detection of animal and plant components. In order to exclude
the possibility of false positive results, restriction endonuclease digestion was used to confirm the results of PCR for
puffer fish components. Eighteen samples were detected, of which 3 samples were sentenced to be negative whereas the
remaining 15 samples were suspected positive based on PCR results. Restriction endonuclease (NmeA Ⅲ) digestion and
agarose gel electrophoresis were used to analyze the PCR products of the suspected positive puffer fish component. The
electrophoresis patterns of PCR fragments digested by NmeA Ⅲ were different from the positive results of puffer fish in 2
non-puffer fish samples, which were judged as false positive. The electrophoresis patterns of 4 samples of processed puffer
fish with unknown scientific names agreed with those of the puffer fish positive samples and were therefore confirmed.
The PCR products were verified by GenBank DNA sequence homology sequence query (BLAST). In conclusion, a
simple method to confirm PCR results of puffer fish ingredients has been established in this study.

Establishment and Comparison of Immunoassays for Detecting Furazolidone Metabolite Based on Different Haptens
SHI Xian-ai1,2, PEI Shi-feng1, LI Xiang-nan1, ZHU Qiu-xiang1, YE Xiao-jun3, FAN Hai-ping3
2014, 35(8):  174-180.  doi:10.7506/spkx1002-6630-201408035
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Based on the haptens of the furazolidone metabolite 3-amino-2-oxazolidinone (AOZ) and its derivative CPAOZ,
mAb-based ELISA kits for the detection of AOZ were established after the preparation of monoclonal antibodies (mAbs)
against AOZ-BSA. The CPAOZ-based ELISA kit indicated excellent linearity over the range of 1.0–100.0 ng/mL, The IC50
was 14.6 ng/mL, with detection limit of 6.56 ng/mL, and the recovery for CPAOZ was 97.6%–101.3%. The AOZ-based
ELISA kit exhibited excellent linearty over the range of 0.5–12.5 ng/mL, The IC50 was 3.9 ng/mL, with the detection limit
of 0.45 ng/mL, and the recovery for AOZ was 94.1%–97.4%. Neither of the ELISA kits showed cross reactivity with other
nitrofurans or their metabolites. Obviously, the AOZ-based ELISA kit has more promising prospects due to its advantages of
economy, convenience, rapidity and sensitivity.

Analysis of 6 Synthetic Sweeteners in Foods by Liquid Chromatography-Quadrupole-Time-of-Flight Mass Spectrometry
WANG Jian-hua1, YANG Jun2, LIU Lin1, YAN Dong-yun2, LI Li3, LIU Jing-jing1
2014, 35(8):  181-186.  doi:10.7506/spkx1002-6630-201408036
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A new method was established for the determination of 6 synthetic sweeteners (sodium saccharin, cyclamate,
acesulfame-K, aspartame, neotame, and sucralose) in food samples by using liquid chromatography-quadrupole-time
of flight mass spectrometry (LC-Q-TOF-MS). The extract was measured directly by LC-Q-TOF-MS with electrospray
ionization in the negative mode. The compounds were separated by an Eclispe XDB-C18 column with acetonitril-10 mmol/L
ammonium formate-0.1% formic acid as the mobile phase. A detailed fragmentation study for these 6 synthentic sweeteners
was carried out by time-of-flight. The 6 compounds behaved linearly in the concentration range of 0.02–2.0 mg/L, with a
correlation coefficient > 0.998. The recoveries were 74.5%–120.1%, with relative standard deviation below 10.4%. The
method illustrated is suitable for routine qualitative and quantitative analyses of synthetic sweeteners in food samples.

Application of PEN3 Electronic Nose Sensor for Rapid Detection of Food-Borne Pathogenic Bacteria
CHEN Li-ping1, XU Mao-qin2, HE Hong-ping1, LI Ye1,*
2014, 35(8):  187-192.  doi:10.7506/spkx1002-6630-201408037
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Four species of common food-borne pathogenic bacteria including Staphylococcus aureus, Escherichia coli,
Streptococcus fecal and Listeria monocytogenes were detected using a metal oxide sensor-based portable electronic nose
(PEN3) according to its different response to bacterial metabolites. Various fingerprints were established for the four
bacteria cultured for 2, 4, 6, 8, and 10 h as well as diluted 103, 105 and 107 times, respectively. The responses of PEN3 to
bacteria under different conditions of incubation time and concentration were analyzed using cluster analysis, principal
component analysis (PCA) and linear discriminant analysis (LDA). Results showed that volatile bacterial metabolites at
different incubation times could be well distinguished by PCA and LDA with the smallest inter- to intra-group variation
ratio. Meanwhile, a significant distinction among these four bacteria was observed even at lower concentration. These results
suggest that chemical sensor technology is feasible in detecting pathogenic bacteria at low concentrations.

Determination of Eight Perfluorinated Compounds in Fish Muscles by Isotope Dilution Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry
HE Xiao-min1,2, CHEN Hao3,*
2014, 35(8):  193-197.  doi:10.7506/spkx1002-6630-201408038
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A method for the rapid determination of eight perfluorinated compounds (PFCs) in fish muscles was developed
by isotope dilution ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS). Samples were
extracted with acetonitrile after addition of eight isotopically labeled internal standards. The extracts were cleaned up on a
WAX solid phase extraction column. The target compounds were separated on a ZORBAX Eclipse plus C18 (100 mm ×
3.0 mm, 3.5 μm) and analyzed by a triple quadruple tandem mass spectrometer with electrospray ionization source (EIS)
in multiple reaction monitoring (MRM) mode. The analytes were quantified by the internal standards labeled with stable
isotopes. The standard curves were linear in the ranges of 0.1–50.0 μg/L for 8 PFCs with correlation coefficients greater than
0.998. The limits of detection were 0.03–0.15 μg/kg. The average recoveries of PFCs in fish muscles were in the range of
87.7%–104.4%. The relative standard deviations (RSD) for PFCs were in the range of 4.1%–10.7%. These results show that
the method is sensitive and accurate, and suitable for the qualitative and quantitative determination of PFCs residues in fish
muscle samples.

Application in Non-Toxic ELISA of Expression of Deoxynivalenol Mimotope Fusion Protein
XU Fu-yong1,2,MENG Wei1, LIU Ren-rong1,*, XU Ling1, QIU Xue-mei1, ZHU Li-xin1
2014, 35(8):  198-203.  doi:10.7506/spkx1002-6630-201408039
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Deoxynivalenol (DON) mimotope, designated as CDON, is a mimicking epitope (CMRPWLQ) screened from a phagedisplayed
random peptide library. In order to replace DON conjugated toxin with non-toxic recombinant protein in ELISA, two
novel expression vectors, which were designated as plasmid pGEX-CDON and phagemid pC89S4-CDON, were used to produce
GST-CDON and pⅧ-CDON fusion proteins in E. coli. After purification, both GST-CDON and pⅧ-CDON fusion proteins showed
good reactogenicity with an anti-DON antibody in a competitive inhibition ELISA test. When GST-CDON was used as coating
antigen, the linear range of the competitive inhibition ELISA was 31–500 ng/mL with an IC50 value of 194 ng/mL, and spiked
recoveries were 54.1%–65.4%, with coefficient of variation of 6.28%–13.37%. The detection limit was 31 ng/mL. Upon using pⅧ-
CDON as coating protein, the linear range of the competitive inhibition ELISA was 15–500 ng/mL with an IC50 value of 94 ng/mL,
and spiked recoveries were 81.7%–89.0%, with coefficient of variation of 3.15%–7.55%. The detection limit was 15 ng/mL.
ELISA analysis and comparison showed that the reactogenicity and specificity of pⅧ-CDON binding to anti-DON antibody
were better than that of GST-CDON fusion protein. Therefore, pⅧ-CDON is promising for establishing an ELISA without the
application of the toxic mycotoxin conjugate.

Comparative Study on Three Different Methods for the Determination of Total Phenolics in Chinese Olive
XIE Qian, WANG Wei, CHEN Qing-xi*
2014, 35(8):  204-207.  doi:10.7506/spkx1002-6630-201408040
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Three analytical methods (ferrous tartrate colorimetry, Folin-phenol reagent method and UV spectrophotometry)
were compared for the determination of total phenolics in Chinese olive in this study. The results showed the three
methods followed the decreasing order: UV spectrophotometry < Folin-phenol reagent method < ferrous tartrate
colorimetry by detection limit and quantitation limit with a significant difference among them (P < 0.05), and ferrous
tartrate colorimetry > Folin-phenol reagent method > UV spectrophotometry by recovery with the difference being not
significant. All these three methods had good repeatability. The polyphenol content determined by Folin-phenol reagent
method and UV spectrophotometry was significantly higher than that determined by ferrous tartrate colorimetry (P < 0.01),
and the polyphenol content determined by Folin-phenol reagent method was slightly higher than that determined
by UV spectrophotometry, with the difference being not significant (P > 0.05). At the same time, there was a good
linear relationship of total polyphenol contents determined by two of them. In comparison two other methods, UV
spectrophotometry proved more suitable for the determination of total phenolics in Chinese olive, thanks to its high
sensitivity, good repeatability, simplicity, rapidity, accuracy and economy.

Development of a Magnetic Particle-Based Enzyme-Linked Immunosorbent Assay for Determining Fumonisin B1 in Corn
GUAN Di1,2,3, PAN Can-ping3, WANG Wen1,2, WU Hui-juan1,2,*
2014, 35(8):  208-211.  doi:10.7506/spkx1002-6630-201408041
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Magnetic particles (MPs) were used as the support to replace enzyme-linked immunosorbent assay (ELISA) plates for
the determination of fumonisin B1 (FB1) in corn. Goat anti-rabbit antibody and protein A-MP conjugates were utilized in a direct
competitive ELISA format. Under optimized conditions, the limits of detection (LOD) for goat anti-rabbit antibody and protein
A-MPs were 0.024 and 0.030 μg/mL, respectively. The goat anti-rabbit antibody MP conjugates exhibited a lower LOD which
was only one third of that of conventional ELISA. The recoveries from spiked corn varied from 76.4% to 110.6%, with relative
standard deviation (RSD) less than 11%. Overall, a sensitive and stable method for FB1 has been developed in this paper.

Determination of Pantothenic Acid in Formula Milk Powder Using Ultra Performance Liquid Chromatography-Isotope Dilution Mass Spectrometry
QU Yan1, CUI Ya-juan1, LI Quan-xia1, CHEN Zhao-tian1, LI Dong1, LIANG Min-hui2
2014, 35(8):  212-216.  doi:10.7506/spkx1002-6630-201408042
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An ultra performance liquid chromatography-isotope dilution mass spectrometry (UPLC-IDMS) method has been
developed for the determination for pantothenic acid (PA) in formula milk powder. Samples were extracted with ammonium
acetate solution, and precipitated protein by adding chloroform for analyzing by UPLC-MS-MS. The analyte was separated
using an HSS T3 column. The mobile phase consisted of 10 mmol/L ammonium acetate with 0.1% formic acid and
acetonitrile. The PA was identified by multiple reaction monitoring (MRM) and quantified by internal standard method.
The results showed that the limit of quantification for PA was 0.040 mg/100 g. The recoveries at three spiked levels and the
relative standard deviations were 96.9%–104.3% and 3.78%–5.04%, respectively. This method proved to be simple, timesaving,
sensitive and accurate for the determination of PA in formula milk powder.

Molecular Design and Synthesis of a Ruthenium Terpyridine Complex for Mercury Determination
LI Xiao-dong, SHAO Ke-feng, XUAN Hong-yun, WU Jun, CHANG Qi-pei, KONG Xiao-guang, ZHAO Bo*
2014, 35(8):  217-221.  doi:10.7506/spkx1002-6630-201408043
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A ruthenium terpyridine complex, 4’-(p-nitrobenzyl)-2,2’:6’,2’’-terpyridineyl-tri-isothiocyanate ruthenium
(Ru(tpy)(NCS)3), was designed and synthesized. Color changes from dark-blue to pink-red could be obviously
observed when different concentrations of mercury (Ⅱ) ions were added to Ru(tpy)(NCS)3 solution. The limit of
naked-eye detection was about 0.03 μg/g while the pink-red color just appeared. Based on the density functional theory
by B3LYP method, then, the geometric configurations of Ru(tpy)(NCS)3 and [Ru(tpy)(NCS)3·HgCl]+ were optimized.
Based on analysis of their frontier molecular orbitals, the basic mechanism of ruthenium complex applied to the
determination of mercury ion was discussed.

Event-specific Detection of Genetically Modified Rice Using Enzyme-Linked Probe Hybridization Chip
ZHANG Ming-zhe1, CHEN Wu-jian1, ZHANG Xiao-feng2, CHEN Xiao-mei2, CHEN Xi1, WU Rong3
2014, 35(8):  222-225.  doi:10.7506/spkx1002-6630-201408044
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The enzyme-linked probe hybridization chip is a method based on ligase-hybridizing probe chip technology with
the principle of using thio-primers for protection, and using Lambda DNA exonuclease to cut multiple PCR amplicons into
single products. 5’-End probe chain is fixed in the amino-modified chip, and hybridized with the single-chain product by
adding the fluorescent-modified probe for the enzyme-linked reactions with the anterior probe in order to achieve highly
specific, parallel and high-throughput detection. In this study, the enzyme-linked probe hybridization chip could effectively
detect genetically modified rice with high specificity and the sensitivity limit was 0.1%. This chip can be used by the entryexit
inspection and quarantine authorities and be applied for food safety testing.

Simultaneous Determination of 11 Poisonous Alkaloids in Chinese Medicinal Herbal Beverages by Liquid Chromatography Tandem Mass Spectrometry
MA Xiao-fei1, LIANG Tian-zuo1, SONG Wei2, FENG Hao-bin1, ZHANG Yan1,*
2014, 35(8):  226-230.  doi:10.7506/spkx1002-6630-201408045
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A method for the simultaneous determination of 11 poisonous alkaloids (aconitine, hypaconitine, mesaconitine, brucine,
strychnine, colchicine, camptothecin, atropine, scopolamine, pilocarpine, and podophyllotoxin) in Chinese medicinal herbal
beverages was developed by liquid chromatography tandem mass spectrometry (LC-MS-MS). Samples were filtered through a
0.22 μm microporous membrane. Qualitative and quantitative analyses were carried out by mass spectrometry under the MRM
mode after the chromatographic separation on a Kinetex C18 (2.1 mm × 100 mm, 2.6 μm) column. All the 11 poisonous alkaloids
showed a good linearity with correlation coefficients (r) no less than 0.999 0 within their linear ranges. The limits of detection for
these poisonous alkaloids were in the range of 0.05 to 0.5 μg/kg. The mean recoveries at three spiked levels were 75.0%–88.4%
and the relative standard deviations were less than 7.6%. This method is simple, sensitive, accurate and suitable for the
simultaneous analysis of poisonous alkaloids in Chinese medicinal herbal beverages.

Determination of Chloramphenicol and Florfenicol in Fishery Products by Using Dispersive Solid Phase Extraction and Gas Chromatography
HU Hong-mei1, GUO Yuan-ming1,*, LEI Ke2, ZHANG Xiao-jun1, YAN Zhong-yong1, HE Yi-na1, YOU Ju-ju1, LIU Qin1
2014, 35(8):  231-235.  doi:10.7506/spkx1002-6630-201408046
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An efficient, sensitive, and low matrix interference method for the determination of chloramphenicol (CAP) and
florfenicol (FF) in fishery products using gas chromatography-electron capture detector (GC-ECD) has been developed.
Samples were treated by extraction with ethyl acetate and n-hexane purification. Further cleanup of the extracts was
processed by a modified dispersive solid phase extraction procedure. Then, the purified solutions were derivatized with slilyl
reagents. The linearity of the method ranged from 1.5 to 100 μg/L for CAP, and from 6 to 400 μg/L for FF, with correlation
coefficients ranging between 0.998 1 and 0.999 7. The limits of detection were 0.1–0.3 μg/kg. The recoveries of spiked CAP
and FF with external calibration method at different concentration levels in different sample matrixes (crucian, blue crab,
and Penaeus vannawei) were 82%–106%, 87%–111%, and 91%–98%, respectively, with relative standard deviations of
2.3%–4.9%, 2.4%–4.5%, and 1.4%–4.1% (n = 5), respectively. Thus it is concluded that this method can be successfully
applied for the determination of choramphenicols (CAPs) in fishery products.

GC-MS Analysis of Aroma Compounds of Kesha Tribute Rice from Yongshun
LIANG Jing1, YANG Dong-mei1, TIAN Xiang-rong1, XIE Wen-hua1, LI Jun-nian1,*, XUE Da-yuan2,*
2014, 35(8):  236-239.  doi:10.7506/spkx1002-6630-201408047
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Aroma components in Kesha tribute rice from Yongshun, South China’s Hunan province were extracted by steam
distillation method and analyzed by gas chromatography-mass spectrometry (GC-MS), and the results were compared with
those for Taohua aromatic rice and Zhijiang rice. A total of 33 volatile components were identified in Kesha tribute rice,
and 31 in Taohua aromatic rice, and 40 in Zhijiang rice, respectively. Aroma-active aldehydes (24.23%), acids (6.64%),
feterocyclic acids (6.35%) and alcohols (6.19%) in Kesha tribut-rice were more abundant than in two other kinds of rice.
The major aroma compounds extracted from Kesha tribute rice were (E)-2-nonenalall (17.77%), 1-hexanol (4.82%),
5-ethyldihydro-2(3H)-furanone (3.39%), undecanal (1.66%), (E,E)-2,4-nonadienal (1.19%), (E,E)-2,4-decadienal (1.55%),
3-nonan-2-one (0.94%) and 2-nonanol (0.94%), all of which were higher than in Taohua aromatic rice and Zhijiang rice.
These results indicate that a larger number of aroma compounds exist in Kesha tribute rice.

Evaluation of Uncertainty in Rhodamine B Determination in Chili Powder by HPLC
NIU Hua, NIU Zhi-rui*, FENG Lei, LU Yan-hua, MA Xue-tao, TAN Jian-lin, ZHANG Xue-zhong, FENG Jin-mei
2014, 35(8):  240-243.  doi:10.7506/spkx1002-6630-201408048
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An uncertainty evaluation model was established for evaluating the determination results of rhodamine B in chili
powder by high performance liquid chromatography (HPLC). In this paper, the key factors affecting the measurement results
during the analysis process were discussed. Meanwhile, the combined and expanded uncertainties were evaluated. During
sample preparation, the recovery of rhodamine B at the purification step by gel permeation chromatography (GPC) made the
most important contribution to the overall uncertainty. Therefore, the stability control of GPC during the purification is the
key point. The uncertainty evaluation model is practical, simple and easy to understand and valuable as a reference.

Determination of 4-(5-)-Methylimidazole and Its Isomer 2-Methylimidazole in Beverage by Ultra Performance Liquid Chromatography Tandem Mass Spectrometry
ZHANG Lu, KONG Xiang-hong, HE Qiang, LI Jian-hua, ZOU Yang, LI Ying
2014, 35(8):  244-248.  doi:10.7506/spkx1002-6630-201408049
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An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS-MS) method was developed
for the determination of 4-(5-)-methylimidazole (4-Mel) and its isomer, 2-methylimidazole (2-Mel), in beverage. Samples
were diluted with water. An OASIS® MCX solid phase extraction column was used to purify and concentrate the target
analytes. Under the optimal conditions, the analytes were separated by a Waters ACQUITY UPLC® HILIC column (2.1 ×
100 mm, 1.7 mm) using a mobile phase consisting of acetonitrile and 5 mmol/L ammonium acetate aqueous solution. The
analytes were detected in multiple-reaction monitoring (MRM) mode via positive electrospray ionization (ESI+). The
results showed that the calibration curves of 4-Mel and 2-Mel were of good linearity in the range of 9–500 ng/mL. The
limit of quantification of the method was 3.0 mg/kg. The average recovery was 97.3% and 93.7% at four spiked levels (3.0,
25, 50 and 75 mg/kg) for 4-Mel and 2-Mel, respectively, and the relative standard deviation (RSD) was 3.8% and 3.4%,
respectively. These figures of merit indicated that the developed method can be used for the determination of 4-Mel and 2-Mel
in beverage samples. This method was applied to different beverages. 4-Mel or 2-Mel was found in soft drink, caramel
colored beverage and coffee. Contrarily, neither of them was found in energy drinks.

Determination of Germanium Bioabsorptivity in Wheat by Graphite Furnace Atomic Absorption Spectrometry after Microwave Digestion
GAO Xiang-yang1,3, GAO Qiu-zhu2, WANG Chang-qing3, CHEN Qi-hang3
2014, 35(8):  249-252.  doi:10.7506/spkx1002-6630-201408050
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The germanium contents in colored and ordinary wheat grains and wheat-field soils from Zhengzhou, Luohe,
Gongyi, Jiaozuo and Shangqiu of Henan province were determined by graphite furnace atomic absorption spectrometry after
microwave digestion and related between wheat grains and soil. The results showed that germanium content in wheat from
Zhengzhou was the highest followed by that from Jiaozuo. The bioabsorptivity of germanium in wheat was closely related
to wheat varieties and soil characteristics. Wheat-cropped soils from Zhengzhou and Luohe contained relatively abundant
levels of germanium. Blue wheat from Zhengzhou showed a bioabsorptivity of germanium as high as 85.2%. In contrast, the
lowest level of 31.9% was observed for grey wheat from Luohe. These results indicate that blue wheat can be a relatively
germanium-enriched food material and has promising prospects.

Analysis of Volatile Compounds in Zhuyeqing Liquor by Headspace Solid Phase Microextraction and
Gas Chromatography-Mass Spectrometry
WANG Zhi-juan1, ZHANG Sheng-wan1,*, ZHAO Jing-long2, LI Mei-ping1, LI Zheng-chun1
2014, 35(8):  253-258.  doi:10.7506/spkx1002-6630-201408051
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The volatile compounds in Zhuyeqing liquor were extracted and enriched by head space-solid phase
microextraction (HS-SPME) and analyzed by gas chromatography-mass spectrometry (GC-MS). The sources and health
functions of the compounds were discussed. At the same time, the effects of SPME fiber type, extraction time, equilibrium
and extraction temperatures and salt dosage on the extraction efficiency of volatile compounds were evaluated. The best
condition was 8.0 mL of sample in a 20-mL headspace glass vial in the presence of 0.20 g/mL salt equilibrated with stirring
at 70 ℃ for 45 min before extraction using a 50/30 μm DVB/CAR/PDMS fiber at 70 ℃ for 45 min. Under this condition,
a total of 65 compounds were isolated, 56 of which were identified structurally, together accounting for 98.16% of the total
volatile substances. Twenty-six of these identified compounds came from the base liquor (compound wine), and the others
came from the traditional Chinese medicines in Zhuyeqing liquor. The major components were D-limonene, eugenol,
caryophyllene, camphol, borneol, camphene, borneol acetate, alpha-santalol, and copaene, totally accounting for 31.63%
of the total volatile components. Despite their relatively low contents, these volatile compounds derived from traditional
Chinese medicines provided Zhuyeqing liquor with a unique fragrance and health functions.

Rapid Determination of Goose Tenderness Using Near Infrared Spectroscopy
YANG Yong, YANG Qing-yu, LIN Wei, WANG Cun-tang, ZHANG Duo, DONG Yuan, SONG Chun-li, PEI Shi-chun*, LI Mao-mao, XU Hong-li
2014, 35(8):  259-262.  doi:10.7506/spkx1002-6630-201408052
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Objective: To propose a rapid method for the identification of goose tenderness by near infrared spectroscopy
(NIR) technology. Methods: NIR spectra (950–1 650 nm) of goose meat were collected. After multiple correction and
pretreatment of the spectra, mathematical models for the quantitative prediction of goose tenderness were established by
principal component regression (PCR) and partial least squares regression (PLSR). Results: The PLSR model based on
five-point moving window smoothing was the best predictive model with a determination coefficient (R2) of 0.908 0 and
a root mean square error of cross validation (RMSECV) of 113.618 6. No significant difference (P > 0.05) was found
between the predicted and measured values for 20 samples in the prediction set, with a correlation coefficient of 0.971 1,
and the predicted values showed an average bias of 21.673 g. Conclusion: NIR can be used in the evaluation of goose meat
tenderness as a fast nondestructive detection method.

Analysis of Volatile Compounds in Pomegranate Wine by Headspace Solid Phase Micro-Extraction and Gas Chromatography-Mass Spectrometry
LI Mei-ping, MIAO Xiao-xiao, ZHANG Sheng-wan*
2014, 35(8):  263-268.  doi:10.7506/spkx1002-6630-201408053
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The volatile compounds in pomegranate wine were analyzed using headspace solid phase micro-extraction and gas
chromatography-mass spectrometry (HS-SPME-GC-MS). The extraction and separation were achieved by using a 50/30 μm
DVB/CAR/PDMS solid-phase micro extraction fiber and an FFAP column, respectively. Single factor and orthogonal array
experiments were conducted to determine the optimal sample preparation conditions as follows: after salt addition at 0.30 g/mL,
8.0 mL of sample per 20.0-mL vial was extracted at 45 ℃ for 50 min, equilibrated for 30 min and then desorbed for 4 min.
Under these conditions, a total of 76 compounds were detected, and 67 of them were structurally identified, accounting for
99.39% of the total amount of volatile components.

Analysis of Volatile Oils from Fruits of Schisandra chinensis (Turcz.) Baill and Schisandra sphenanthera Rehd. et Wils. by Ultrasonic-Microwave Assisted Steam Distillation Coupled with Gas Chromatography-Mass Spectrometry
LI Xin1, NIE Jing1, GAO Zheng-de1, LI Zu-guang1,*, DENG Feng-tao2, WU Xian-wei2
2014, 35(8):  269-274.  doi:10.7506/spkx1002-6630-201408054
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In this study, the chemical components of volatile oils from the fruits of Schisandra chinensis (Turcz.) Baill
and Schisandra sphenanthera Rehd. et Wils. were extracted using either ultrasonic-microwave assisted steam distillation
(UMASD) or traditional steam distillation (SD) and analyzed by gas chromatography-mass spectrometry. The yield of
volatile oil extracted by SD and UMASD was 1.2% and 1.4% from Schisandra sphenanthera Rehd. et Wils. fruits, and 1.3%
and 1.8% from Schisandra chinensis (Turcz.) Baill fruits, respectively. The results of qualitative analysis based on retention
index through NIST spectral library searching showed that 50 and 54 compounds were identified from the volatile oils from
Schisandra sphenanthera Rehd. et Wils. fruits extracted by SD and UMASD, respectively, and 54 and 55 compounds in
the volatile oils from Schisandra chinensis (Turcz.) Baill extracted by the two methods, respectively. The four volatile oils
mainly consisted of alcohols, ketones, esters and alkyl compounds. Their composition and contents varied depending on
location and sample pretreatment. The SD process took 6 h, while the extraction time was shortened to 1 h for UMASD. The
present study suggestes that UMASD is an efficient, rapid, simple and green technique for the extraction of volatile oil from
plant matrices.

Determination and Fingerprint Analysis of Fatty Acid Composition of Antrodia camphorata Powder by GC-MS
ZHANG Feng-su, CHEN Fei, LIU Xun-hong*, YANG Nian-yun, HOU Ya, MA Yang, LU Juan-juan
2014, 35(8):  275-278.  doi:10.7506/spkx1002-6630-201408055
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Purpose: To analyze the composition of fatty acids extracted from Antrodia camphorata powder and establish a
fingerprint analysis method for the edible fungus. Methods: Essential oil was extracted from Antrodia camphorata powder
bysupercritical CO2 extraction method, and analyzed by gas chromatography-mass spectrometry (GC-MS) for fatty acid
composition after methyl esterification. Using palmitic acid as the reference, the chromatographic fingerprint of the essential
was established. Data were analyzed by fingerprint similarity evaluation software to compare the similarity of samples.
Results: Antrodia camphorata powder contained 33 fatty acids, including 18 unsaturated fatty acids, accounting for 75.29%
of the total amount of fatty acids. Fatty acid fingerprints with 11 common peaks for Antrodia camphorata were established.
Conclusion: This study provides an experimental basis for the quality assessment of Antrodia camphorata powder, and
research and development of health food products.

Effects of Cold Pressing and Hot Pressing on Acidic Value and Unsaturated Fatty Acid Contents of Perilla Oil
CHEN Lin, LI Rong, LIU Tao, JIANG Zi-tao*
2014, 35(8):  279-282.  doi:10.7506/spkx1002-6630-201408056
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The fatty acid contents in cold-pressed and hot-pressed perilla oils were determined by reversed phase high
performance liquid chromatography with evaporative light scattering detector (HPLC-ELSD) in a gradient elution mode
after conversion of the triglycerides into free fatty acids by alkaline hydrolysis. The results showed that the differences in
the contents of fatty acids in cold-pressed and ho-pressed perilla oils were highly significant. The contents of linolenic and
linoleic acids in cold-pressed perilla oil were significantly higher, whereas the contents of oleic acid and palmitic acid were
relatively lower than in hot-pressed oil. The content of five fatty acids accounted for up to 95.09% of total fatty acids in coldpressed
oil, but only 87.89% in hot-squeezed oil. The recoveries of five fatty acids were 99.70%–101.11%, with relative
standard derivations (RSDs) between 0.44% and 3.66%.

Establishment and Application of Dansyl Chloride Precolumn Derivatization RP-HPLC for Determination of Histamine in Aquatic Products
HU Jia-wei1, GAO Rong2, CAO Min-jie1, CAI Qiu-feng1, ZHANG Ling-jing1, SU Wen-jin1, LIU Guang-ming1,*
2014, 35(8):  283-288.  doi:10.7506/spkx1002-6630-201408057
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A precolumn derivatization with dansyl chloride reversed high performance liquid chromatographic (RP-HPLC)
method was developed for rapid determination of histamine in aquatic products. Samples were extracted with trichloroacetic
acid, derivatized with dansyl chloride before separation on a C18 columnusing an isocratic elution program with a mixture of
70% acetonitrile and 30% ultra-pure water and detection at 254 nm. The results showed that the retention time of histamine
was 5.5 min. The linear range of histamine was 1–500 μg/mL with a correlation coefficient of 0.999 9. The limit of detection
(RSN = 3) was 0.5 μg/mL and the limit of quantization (RSN = 10) was 1.0 μg/mL. The repeatability of the instrument was
good. In 16 aquatic products and 19 processed aquatic products, histamine levels were detected as being between 0 and
682.22 mg/kg by the method. The average recoveries of histamine at different spiked concentration levels in blank samples
were between 84.54% and 101.92%. This method proved rapid, accurate, sensitive, and reproducible and could be used for
determining histamine in aquatic products. Moreover, the levels of histamines in skipjack tuna, mackerel and blue scad were
detected at different temperatures as a function of storage by this method. The results showed that the contents of histamine
were significantly lower at lower temperatures than at higher temperatures, revealing that the production of histamine can be
inhibited at a lower temperature.

A Novel Ultrasensitive Method for Detection of Melamine Based on Signal Amplified Lateral Flow Chromatographic Strips
ZHONG You-hao, ZHAO Di-ping, XUE Feng, ZHU Meng-ya, FANG Wei, CHEN Wei*
2014, 35(8):  289-294.  doi:10.7506/spkx1002-6630-201408058
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This paper reports on a convenient and rapid method for the detection of melamine in food samples by lateral
flow strip technology. The method is based on competitive immunoreaction. The traditional test strip was made much more
sensitive by adding an enhancement pad. For the melamine lateral flow strip, 25 nm and 15 nm colloidal gold nanoparticles
were adopted in the recognition and enhancement pads, respectively. The results showed that detection of melamine in food
samples could be achieved in less than 10 min. The limit of detection (LOD) of the enhanced lateral flow strip was 0.5 μg/L
under our experimental conditions, which showed a 20-fold increase over 10 μg/L for the traditional lateral flow strip. This
new method was able to detect 0.1–5 μg/L melamine in real samples and the sensitivity was 1 μg/L, indicating a 5-fold
increase over that of the traditional one.

Simultaneous Determination of 8 Organochlorine Pesticide Residues in Chili Sauce by Gas Chromatography with Matrix Solid Phase Dispersion-Gel Permeation Chromatography Cleanup
ZHANG Quan, CHEN Wen-sheng*, HONG Liang, JIN Chun-jie, CHU Hong-chao
2014, 35(8):  295-298.  doi:10.7506/spkx1002-6630-201408059
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An analytical method has been developed for the determination of 8 organochlorine pesticides in chili sauce
samples. Samples were treated by matrix solid phase dispersion (MSPD) to remove most interferences such as fat and
sterols, and then cleaned up by on-line gel permeation chromatography. The analysis was performed by gas chromatography
with electron capture detection (GC-ECD). The correlation coefficient for the standard curves was 0.999 1–0.999 6, the
recoveries obtained by standard addition method were between 74.58% and 102.86% and the intra-day RSD was lower than
5.45% (n = 5). The limits of detection (LOD) ranged from 0.40 to 1.20 μg/kg. This method is characterized by low detection
limit, high sensitivity, rapidity and accuracy, so that it can be used to detect organochlorine pesticide residues in chili sauce.

Rapid Detection of Meat Injected with Water or Gum by Near Infrared Spectroscopy
MENG Yi1, ZHANG Yu-hua1,2,*, XU Li-dan1,2, CHEN Dong-jie1,2, ZHANG Ying-long1,2, ZHANG Yong-mei1
2014, 35(8):  299-303.  doi:10.7506/spkx1002-6630-201408060
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A qualitative model for discriminating water-injected meat, gum-injected meat from normal meat was established by
near infrared spectroscopy (NIR) combined with principal component analysis (PCA) and discriminant analysis. The amount of
water injection had an impact on the discrimination accuracy. The overall discrimination accuracy between normal and adulterated
meat was 94.23% when the amount of water injection was 1.25%–20%, and was increased to 96.96% upon water injection at levels
between 3.75% and 20%. The overall discrimination accuracy for all samples in the prediction set was 94.92%. These results show
that NIR combined with PCA and discriminant analysis is feasible to discriminate water-injected meat, gum-injected meat from
normal meat. Quantitative analysis models of water injection and gum injection were established using partial least squares (PLS)
combined with PCA. On the basis of verification, the root mean square errors of prediction (RMSEP) from the two models were
4.01% and 3.87%, respectively, and the correlation coefficients (r) between the predicted values and the actual values were 0.904 2
and 0.912 8, respectively. Therefore, both models have good prediction performance.

Preparation of Solid Polymer Microsphere Immune Adsorbent and Its Adsorption Performance for Aflatoxin M1
ZHANG Xiao-zhou 1, ZHEN Yu-ping2, GAO Jian-wei2, WANG Yan2, PEI Shi-chun 2,*
2014, 35(8):  304-308.  doi:10.7506/spkx1002-6630-201408061
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In this paper, immune adsorbents were prepared for the adsorption of aflatoxin M1 in milk. Copolymer
microspheres of glyceryl methacrylate (GMA) and methyl methacrylate (MMA) were prepared using dispersion
polymerization with azodiisobutyronitrile (AIBN) as initiator in aqueous ethanol medium in the presence of
polyvinylpyrrolidone (PVP) as dispersant under various conditions. Anti-AFM1 monoclonal antibody was coupled with the
epoxy groups on the microsphere surface to form an immune adsorbent. The microsphere particle size was approximately
1.7 μm, and the quantity of epoxy group in the microspheres was between 67.2% and 71.6%. The adsorption quantity of
monoclonal antibodies for aflatoxin M1 in milk was more than 1.2 μg/g. These results show that the selective adsorption
for aflatoxin M1 in milk of the immune adsorbent is good. It can be an ideal immune adsorption material for the removal of
aflatoxin M1 in milk.

Development of Semiquantitative Colloidal Gold Test Strip for Neomycin
WANG Li-zhe1, ZHAO Yu1, TANG Hui-lin1, WANG Li-li1, YU Zhong-nan1, LIU Min1, HE Yan-ling2
2014, 35(8):  309-312.  doi:10.7506/spkx1002-6630-201408062
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A simple and rapid method based on colloidal gold immunochromatography for the detection of
neomycin residues in milk was established. Two different concentrations of complete antigen for artificially synthetic
neomycin were coated onto a nitrocellulose membrane as the test lines (T1, T2), which could compete the binding between
neomycin monoclonal antibody coating colloidal gold and the free neomycin in milk samples. In this way, the accuracy of
traditional neomycin colloidal gold test strip was improved from qualitative to semi-quantitative detection by the color of
T1 and T2 lines. The semi-quantitative detection limits of the test lines T1 and T2 for milk samples were 200 and 400 μg/kg,
respectively, which could meet the requirement of the EU and the national standard for the determination of the maximum
residue limit (MRL) of neomycin. Also, this test strip enabled rapid on-site detection of neomycin residues in milk samples.