快速滤过型净化法结合气相色谱-四极杆-飞行时间质谱同时筛查果蔬中234种农药残留

孟志娟,黄云霞,邸鹏月,赵丽敏,牛立沙,范素芳*,李 强*,张 岩

(河北省食品检验研究院 河北省食品安全重点实验室,河北 石家庄 050091)

摘 要:建立快速滤过型净化法结合气相色谱-四极杆-飞行时间质谱同时筛查蔬菜和水果中234 种农药残留的方法。样品经过乙腈提取,提取液用m-PFC柱净化后,经气相色谱-四极杆-飞行时间质谱仪测定。通过保留时间和全扫描离子精确质量数定性,基质标准曲线定量,能够有效去除基质干扰。对12 种典型果蔬样品(白菜、芹菜、番茄、黄瓜、菠菜、韭菜、油菜、橘子、梨、苹果、葡萄、橙子)进行实际样品验证。结果表明,234 种农药在5~500 μg/kg范围内线性良好,相关系数大于0.990,方法的检出限为5~20.0 μg/kg。样品在10、50、100 μg/kg 3 个添加水平的平均加标回收率分别为73.2%~124.8%、75.5%~122.6%和74.8%~121.7%,平均相对标准偏差分别为2.4%~13.2%、2.8%~11.4%和2.2%~10.5%。该方法有效地提高了高分辨质谱在进行果蔬农药高通量筛查时的检测效率,具有较强的实际应用价值。

关键词:气相色谱-四极杆-飞行时间质谱;快速滤过型净化;农药残留;快速筛查;果蔬

农药在保护农作物生长、提高农作物产量和保障农产品储存质量等方面起到了至关重要的作用。但同时农药残留对食品安全、生态环境和人体健康的影响也不可避免。随着农药品种增多,多种农药的混合使用和滥用致使农产品中多种农药残留现象比较突出。农药残留问题已经成为国际共同关注的食品安全重大问题之一,许多国家和国际性组织(如美国、日本、中国、欧盟和韩国等)针对农产品中农药残留的污染现状制定了农药最大残留限量标准,有些农药化合物限量水平低至10 μg/kg,并呈现逐年严格的趋势[1]。这些标准的实施加强了农药的监管力度,明确其种类和含量水平保证了农药的规范化使用、保障了农产品安全和避免了贸易纠纷。但与此同时,如此繁多的农药最大残留限量法规对农药残留的监控提出了新的难题,因此采用先进的分析技术测定农产品中多种农药残留同时还要避免由多种不同食品基质造成的基质干扰显得尤为重要[2-4]

目前,在进行农药残留检测时,样品前处理方法有固相萃取法[5]、凝胶渗透色谱法[6-7]和QuEChERS法[8]等。其中QuEChERS方法是一种简单、快速的农药残留预处理技术,其原理是利用吸附剂填料与基质中的杂质相互作用,吸附杂质,从而达到除杂净化的目的,是美国官方分析化学师协会认证的方法(AOAC 2007.01)和欧洲标准化委员会认证的欧盟标准方法(EN 15662-2008)[9-10],已广泛应用于果蔬、小麦粉和人参等的分析中[1 1-1 5]。农药残留检测方法主要为气相色谱(gas chromatography,GC)法[16]、液相色谱(liquid chromatography,LC)法[17-18]、气相色谱-质谱(gas chromatography-mass spectrometry,GC-MS)法[19-20]和液相色谱-质谱(liquid chromatography-tandem mass spectrometry,LC-MS/MS)法[21-23],其中GC和LC定性能力弱,而GC-MS和LC-MS/MS为低分辨质谱。当样品基质复杂时,质荷比(m/z)接近的目标物和干扰物不能有效地区分,常出现假阳性而造成误判。同时在选择离子扫描(selected ion monitor,SIM)或多反应监测(multiple reaction monitoring,MRM)扫描模式下,由于仪器扫描速率不高,限制了扫描的化合物数量,无法真正实现高通量筛查。在采用GC-MS和LC-MS/MS分析几百种农药时,往往需要把化合物分成几组进行分别检测[24-25],降低了分析速度,而在全扫描模式时,其灵敏度低、分辨率差,不能准确定性[26]。此外,GC-MS和LC-MS/MS的定性分析必须依赖标准物质。而标准物质的配制和使用,增加了实验成本和分析的工作量。飞行时间质谱(time-of-flight mass spectrometry,TOF-MS)法利用动能相同、m/z不同的离子在恒定电场中运动时,经过恒定距离所需时间不同的原理,对物质成分或结构进行测定,通过与四极杆质量分析器串联,更大程度地提高定量准确度和线性范围。其定性能力强和筛查能力高,测定化合物不受数量限制,可采集更为全面的化合物信息,越来越多地应用于多种目标化合物的测定,在污染物痕量分析中优势突出,已开始广泛应用[27-30]。TOF-MS还可建立特定化合物数据库,结合样品采集的精确质量数、保留时间、同位素比值等信息,通过软件进行自动检索和分析确证,从而实现不使用标准品对目标化合物进行快速鉴定[31-32]。近年来,利用气相色谱-四极杆-飞行时间质谱(gas chromatography-quadrupole time of flight mass spectrometry,GC-QTOF-MS)检测农药残留成为新的研究方向。GC-QTOF-MS同时具有高分辨率和高灵敏度特点,能对复杂基质的低含量水平目标化合物进行筛查和定量分析,目前GC-QTOF-MS已经用于水产品[33]和果蔬[34-35]等农药残留研究中。常规的监测项目中涉及农药化合物几百种,检测方法必须能够一次处理多种化合物,同时还要避免多种基质造成的基质干扰。使用GC-QTOF-MS进行农药筛查的精确质量数方法确保了农药鉴定的可靠结果,并能够对新添加的化合物进行回溯性分析,大大增加了化合物进行同步筛查的数量。快速滤过型净化(multi-plug filtration cleanup,m-PFC)法是基于QuEChERS方法开发的一种新型快速样品前处理净化柱,将多壁碳纳米管、乙二胺-N-丙基硅烷(primary secondary amine,PSA)和C18固相材料填入柱体管中制成,可实现一步法净化,从而大大缩短净化时间,可大幅提高前处理速率和效率,已用于人参、果蔬中多种农药残留检测[36-38]。但以m-PFC净化结合GCQTOF-MS技术应用于果蔬中多种农药残留量的检测国内外鲜见报道。

本实验根据目标物的性质,采用基于m-PFC净化改进的QuEChERS方法,建立了12 种典型果蔬(白菜、芹菜、番茄、黄瓜、菠菜、韭菜、油菜、柑橘、梨、苹果、葡萄、橙子)基质中234 种农药的GC-QTOF-MS测定方法。该方法具有检测速度快、通量高、结果准确可靠的特点,适用于大量样品中农药多残留快速筛查分析。

1 材料与方法

1.1 材料与试剂

果蔬(白菜、芹菜、番茄、黄瓜、菠菜、韭菜、油菜、橘子、梨、苹果、葡萄、橙子) 市购。

乙腈(色谱纯) 德国Merck公司;m-PFC小柱(简单基质包括150 mg MgSO4、15 mg PSA和15 mg MWCNTs)、m-PFC小柱(复杂基质包括150 mg MgSO4、15 mg PSA和25 mg MWCNTs)、乙酸缓冲盐体系盐包(包括6 g MgSO4和1.5 g醋酸钠) 北京绿绵科技有限公司。

234 种农药标准品物质购自阿尔塔科技有限公司,以乙腈配制234 种农药混合标准储备液,质量浓度均为10 μg/mL,置于-18 ℃冰箱贮存。

1.2 仪器与设备

7200 GC-QTOF MS质谱仪、HP-5MS石英毛细管柱(30 m×0.25 mm,0.25 μm) 美国Agilent公司;3K15型高速冷冻离心机 德国Sigma公司;Vortex涡旋混合器德国IKA公司;KQ-250DB型数控超声波清洗器 昆山市超声仪器有限公司;冰箱 中国青岛海尔股份有限公司;0.22 μm微孔滤膜 天津艾杰尔公司。

1.3 方法

1.3.1 提取方式

称取已均质好的新鲜果蔬样品15.0 g(精确到0.001 g)于50 mL塑料离心管中,加入15 mL乙腈,充分混匀,超声10 min,加入乙酸缓冲盐体系盐包,涡旋1 min,放入冰水浴中2 min,在9 500 r/min离心3 min。

1.3.2 净化方式

m-PFC净化:取上清液2 mL,移入m-PFC小柱上端,缓慢推动注射杆,过0.22 μm有机滤膜后,用气相小瓶承接流出液,待GC-QTOF-MS进样分析。

1.3.3 标准溶液的配制

用基质空白提取液稀释234 种农药混合标准储备液,配制质量浓度分别为0.005、0.02、0.05、0.1、0.5 μg/mL的系列标准溶液。基质混合标准溶液应现配现用。

1.3.4 加标回收实验

采用1.3.1节和1.3.2节中样品提取和净化方式,对12 种果蔬基质(白菜、芹菜、番茄、黄瓜、菠菜、韭菜、油菜、柑橘、梨、苹果、葡萄、橙子)234 种农药进行回收率添加实验,添加量分别为10、50、100 μg/kg,在选定的色谱-质谱条件下上机测定,每个水平重复6 次。

1.3.5 仪器条件

1.3.5.1 色谱条件

HP-5MS色谱柱(30 m×0.25 mm,0.25 μm);进样口温度:280 ℃;升温程序:初始温度60 ℃,保持1 min,以40 ℃/min升温至120 ℃,再以5 ℃/min升温至310 ℃;载气:氦气(纯度≥99.999%);流速:0.935 mL/min;进样方式:不分流进样;进样体积:2 μL。

1.3.5.2 质谱条件

离子化模式:电子电离源;电子能量:70 eV;离子源温度:280 ℃;传输线温度:300 ℃;采集模式:TOFScan全扫描;一级质量数扫描范围:m/z 50~550,采集速率2 spectrum/s;溶剂延迟:4 min;安捷伦MassHunter工作软件。

1.4 数据库的建立

在优化色谱条件下进样,对234 种化合物进行一级质谱全扫描,在定性软件中设置谱库检索及标注分子式参数,通过积分并查找化合物找到目标化合物,将检索结果并标注分子式的结果发送至PCDL库。通过在PCDL据库软件中输入每种农药的名称、保留时间、分子式、精确相对分子质量、CAS号,建立234 种化合物的一级精确质量数PCDL库,见表1。

表1 234 种化合物的保留时间、碎片离子和精确质量数
Table 1 Retention times, fragment ions and accurate masses of 234 pesticides

碎片1 碎片2 碎片3分子式 m/z 分子式 m/z 分子式 m/z甲胺磷 5.844 C2H8NO2PS 141.000 8 CH5NO2PS 125.977 3 CH5NO2P 94.005 2敌敌畏 6.153 C2H6O3P 109.004 9 C2H7ClO3P 144.981 6 C4H7ClO4P 184.976 5敌草腈 7.676 C7H3Cl2N 170.963 7 C7H3ClN 135.994 9 C7H3Cl2N 172.960 8茵草敌 7.782 C7H14NOS 160.079 1 C7H4NOS 128.107 0 C6H14NS 132.084 1烯丙酰草胺 7.789 C8H11ClNO 172.052 4 C5H6Cl2NO 165.982 1 C8H10NO 136.075 7速灭磷 9.043 C6H9O5P 192.018 2 C5H9O4P 164.023 3 C2H8O4P 127.015 5灭草敌 9.335 C7H15NOS 161.086 9 C7H16NS 146.099 8 C7H14NO 128.107 0氯唑灵 9.540 C5H5Cl2N2OS 210.949 4 C3HCl2N2OS 182.918 1 C5H535Cl37ClN2OS 212.946 5氯苯甲醚 10.552 C6H5Cl2O 162.971 2 C7H5Cl2O2 190.966 1 C8H8Cl2O2 205.989 6庚烯磷 11.886 C9H12O4P 215.046 8 C7H5Cl 124.007 4 C2H5O3P 109.004 9燕麦酯 12.125 C10H9ClO2 196.028 6 C9H6ClO 165.010 2 C7H6Cl 125.015 3氟啶虫酰胺 12.380 C7H3F3NO 174.016 1 C6H3F3N 146.021 2 C6H2F2N 126.015 0四氯硝基苯 12.407 C6HCl4NO2 258.875 6 C5HCl4 200.882 7 C6HCl4 212.882 7毒草胺 12.550 C11H14NO 176.107 0 C9H10N 132.080 8 C8H10N 120.080 8残杀威 12.553 C5H5O 81.033 5 C6H6O2 110.036 2 C9H12O2 152.083 2灭线磷 12.991 C2H7O2PS2 157.962 0 C5H13O2PS2 200.008 9 C2H8O2PS 126.997 7氟氯氢菊脂 13.190 C3H4ClN5 145.015 0 C4H5ClN5 158.022 8 C5H8ClN5 173.046 3甲基苯噻隆 13.435 C7H5NS 135.013 7 C8H7N2S 163.032 4 C6H4S 108.002 8杀虫脒 13.442 C9H10ClN2 181.052 7 C8H7ClN 152.026 2 C10H13ClN2 196.076 2去乙基阿特拉津 13.475 C3H4ClN5 145.015 0 C6H10ClN5 187.061 9 C5H7ClN5 172.038 4 2,6-二氯苯甲酰胺 13.625 C7H5Cl2NO 188.974 3 C7H3Cl2O 172.955 5 C7H3Cl2N 170.963 7噁虫威 13.800 C8H7O3 151.039 0 C9H10O3 166.062 4 C6H6O3 126.031 1氟乐灵 13.926 C8H5F3N3O4 264.022 7 C11H11F3N3O4 306.069 6 C8H5F3N3O3 248.027 8乙丁氟灵 14.016 C13H8F2N3O3 292.052 8 C8H5F3N3O4 264.022 7 C7H5F3N2O2 206.029 8化合物 保留时间/min

续表1

化合物 保留时间/min分子式 m/z 分子式 m/z 分子式 m/z硫线磷 14.066 C2H8O2PS2 158.969 8 C6H14O2PS2 213.016 7 H4O2PS2 130.938 5治螟磷 14.086 C8H20O5P2S2 322.022 2 C4H12O5P2S2 265.959 6 C4H11O3PS2 201.988 2猛杀威 14.165 C9H11O 135.080 4 C10H14O 150.103 9 C7H7 91.054 2甲拌磷 14.195 C5H12O2FS3 230.973 2 C4H10O2P 121.041 3 H2O2PS 96.950 8 α-六六六 14.305 C6H4Cl3 180.937 3 C6H435Cl237Cl 182.934 4 C6H535Cl337Cl 218.911 1西玛通 14.563 C8H15N5O 197.127 1 C6H11N5O 169.095 8 C5H7N4O 139.061 4五氯甲氧基苯 14.782 C6Cl5O 262.838 6 C635Cl437ClO 264.835 7 C7H335Cl437ClO 279.859 2乐果 14.845 C3H5NS 87.013 7 C2H6O2PS 124.982 1 C2H8O3PS 142.992 6乙氧喹啉 15.005 C13H16NO 202.122 6 C11H12NO 174.091 3 C10H11N 145.088 6西玛津 15.051 C5H8ClN5 173.046 3 C6H9ClN5 186.054 1 C7H12ClN5 201.077 6扑灭通 15.147 C6H10N5O 168.088 0 C9H16N5O 210.134 9 C10H19N5O 225.158 4绿谷隆 15.254 C9H2O 126.010 5 C7H4ClNO 152.997 6 C9H11ClN2O2 214.050 4莠去津 15.287 C5H8ClN5 173.046 3 C7H11ClN5 200.069 7 C8H14ClN5 215.093 2 β-六六六 15.333 C6H4Cl3 180.937 3 C6H435Cl237Cl 182.934 4 C6H535Cl337Cl 218.911 1异噁草酮 15.370 C7H6Cl 125.015 3 C10H2O 138.010 5 C12H14NO2 204.101 9扑灭津 15.472 C5H7ClN5 172.038 4 C8H13ClN5 214.085 4 C9H16ClN5 229.108 9特丁通 15.536 C5H8N5O 154.072 3 C6H11N5O 169.095 8 C9H16N5O 210.134 9 γ-六六六 15.562 C6H4Cl3 180.937 3 C6H435Cl237Cl 182.934 4 C6H535Cl337Cl 218.911 1灭害威 15.662 C8H8O 120.057 0 C8H10NO 136.075 7 C9H13NO 151.099 2环莠隆 15.721 C5H7 67.054 2 C6H11N2O 127.086 6 C9H16NO 154.122 6五氯硝基苯 15.755 C5Cl5 234.843 7 C535Cl437Cl 236.840 8 C635Cl437ClNO2 294.833 7 37ClN 274.843 9杀螟腈 15.828 C2H6O3P 109.004 9 C2H6O2PS 124.982 1 C9H10NO3PS 243.011 4咯喹酮 15.851 C9H8N 130.065 1 C10H10N 144.080 8 C11H11NO 173.083 5草达津 15.904 C6H9ClN5 186.054 1 C7H11ClN5 200.069 7 C8H13ClN5 214.085 4地虫硫磷 15.937 C2H6OPS 108.987 1 C4H10OPS 137.018 4 C10H15OPS2 246.029 6胺丙畏 15.937 C7H6OS 138.013 7 C7H13NO3PS 222.034 8 CH5NOPS 109.982 4炔苯酰草胺 15.970 C7H3Cl2O 172.955 5 C11H8Cl2NO 239.997 7 C12H10Cl2NO 254.013 4嘧霉胺 16.143 C12H13N3 199.110 4 C12H12N3 198.102 6 C11H9N3 183.079 1二嗪磷 16.405 C10H15N2O 179.117 9 C7H9N2O 137.070 9 C10H17N2O3PS 276.069 2乙拌磷 16.484 H2O2PS 96.950 8 C4H10O2PS 153.013 4 C2H6O2PS 124.982 1 δ-六六六 16.488 C6H4Cl3 180.937 3 C6H435Cl237Cl 182.934 4 C6H535Cl337Cl 218.911 1仲丁通 16.604 C6H11N5O 169.095 8 C8H14N5O 196.119 3 C9H16N5O 210.134 9氨氟灵 16.674 C11H10F3NO3 261.059 9 C10H10F3N4O4 307.064 9 C11H12F3N4O3 305.085 6百菌清 16.680 C8Cl4N2 263.881 0 C835Cl337ClN2 265.878 1 C835Cl237Cl2N2 267.875 2兹克威 16.740 C9H10O 134.072 6 C9H12NO 150.091 3 C10H15NO 165.114 8野麦畏 16.823 C4H8NO 86.060 0 C3H2Cl3 142.921 7 C10H16Cl2NOS 268.032 4氯唑磷 16.866 CH2N3O2P 118.988 1 C8H6N2O2 162.042 9 C9H6ClN2O3S 256.978 5氟虫脲 17.038 C9H4N 126.035 0 C13H8ClF4NO 305.022 5 C13H837ClF4NO 307.020 7丁基嘧啶磷 17.148 C8H12N2O 152.094 4 C11H8NO3S 234.022 3 C13H23N2O3PS 318.116 2解草嗪 17.211 C7H6NO 120.044 4 C8H8NO 189.078 4 C11H11Cl2NO2 259.016 1安硫磷 17.264 C2H6O2PS 124.982 1 C3H7O2PS2 169.962 0 C6H11NO4PS 224.014 1五氯苯胺 17.307 C6HCl3N 191.916 9 C6H2Cl5N 262.862 4 C6H235Cl437ClN 264.859 5氯硫酰草胺 17.672 C7H5Cl2NS 204.951 4 C7H3Cl2N 170.963 7 C7H335Cl37ClN 172.960 8敌稗 17.695 C9H9Cl2NO 217.005 6 C6H5Cl2N 160.979 4 C6H535Cl37ClN 162.976 3环丙津 17.752 C9H14ClN5 227.093 2 C8H11ClN5 212.069 7 C5H5ClN5 170.022 8除线磷 17.762 C8H9ClO3PS 250.969 3 C7H5Cl2O2S 222.938 2 C10H13ClO3PS 279.000 6二甲草胺 17.772 C9H12N 134.096 4 C9H10N 132.080 8 C11H13ClNO 210.068 0二甲吩草胺 17.812 C8H12NS 154.068 5 C8H10ClNOS 230.040 1 C10H13ClNSO 203.016 6溴丁酰草胺 17.835 C9H11 119.085 5 C15H22NO 232.169 6 C14H19BrNO 296.064 5呋嘧醇 17.841 C4H3N2 79.029 1 C5H3N2O 107.024 0 C12H8F3N2O2 269.053 2麦穗宁 18.034 C10H7N2 155.060 4 C10H8N2 156.068 2 C11H8N2O 184.063 1乙草胺 18.037 C10H12N 146.096 4 C10H12NO 162.092 3 C12H14ClNO 223.076 2甲基对硫磷 18.080 C2H6O3P 109.004 9 C8H10NO4PS 247.006 3 C8H10NO5PS 263.001 2甲基毒死蜱 18.090 C7H7Cl2NO3PS 285.925 6 C7H735Cl37ClNO3PS 287.923 2 C2H6O2PS 124.982 1乙烯菌核利 18.103 C7H3Cl2NO 186.958 6 C10H8Cl2N 212.002 8 C12H9Cl2NO3 284.995 4五氯苯甲腈 15.821 C735Cl337ClN 239.875 0 C7Cl5N 272.846 8 C735Cl4碎片1 碎片2 碎片3

续表1

化合物 保留时间/min碎片1 碎片2 碎片3分子式 m/z 分子式 m/z 分子式 m/z特草灵 18.127 C12H17O 177.127 4 C14H21O 205.158 7 C15H24O 220.182 2甲基立枯磷 18.253 C8H8ClO3PS 249.961 5 C9H11ClO3PS 264.985 0 C9H1137ClO3PS 266.982 0七氯 18.286 C5Cl6 269.812 6 C535Cl537Cl 271.809 6 C535Cl437Cl2 273.806 7四氟苯菊酯 18.376 C7H8Cl 127.030 9 C7H3F4 163.016 5 C15H12ClF4O2 335.045 6甲草胺 18.405 C10H12N 146.096 4 C11H14N 160.112 1 C12H14NO 188.107 0莠灭净 18.442 C5H8N5S 170.049 5 C8H14N5S 212.096 4 C9H17N5S 227.119 9灭草环 18.591 C7H3Cl2O 172.955 5 C8H5Cl2O 186.971 2 C9H4Cl3 216.937 3扑草净 18.604 C6H10N5S 184.065 1 C9H16N5S 226.112 1 C10H19N5S 241.135 6甲霜灵 18.621 C11H14N 160.112 1 C12H16NO2 206.117 6 C13H16NO3 234.112 5八氯二丙醚 18.667 CHCl2 82.945 0 C3H3Cl2 108.960 6 C2HCl3 129.913 8苄草丹 18.767 C7H7 91.054 1 C7H14NO 128.106 9 C14H21NOS 251.133 7坪草丹 18.996 C5H10NO 100.075 7 C7H6Cl 125.015 3 C12H16NOS 222.094 7特丁净 19.066 C6H11N5S 185.073 0 C9H16N5S 226.112 1 C10H19N5S 241.135 6氟硫草定 19.122 C13H15FO2S2 286.049 2 C13H9F5NO2 306.054 8 C14H13F5NO2S 354.058 2杀螟硫磷 19.152 C2H6O2PS 124.982 1 C9H11NO4PS 260.014 1 C9H12NO5PS 277.016 8除草定 19.212 C5H679BrN2O2 204.960 7 C5H681BrN2O2 206.958 7 C7H879BrN2O2 230.976 4利谷隆 19.241 C9HClO 159.971 5 C7H3Cl2NO 186.958 6 C9H10Cl2N2O2 248.011 4甲基嘧啶磷 19.291 C9H14N3O 180.113 1 C10H17N3O3PS 290.072 3 C11H20N3O3PS 305.095 8戊草丹 19.295 C7H7 91.054 2 C11H16N 162.127 7 C12H16NOS 222.094 7乙氧呋草黄 19.298 C10H9O2 161.059 7 C12H15O3 207.101 6 C13H18O5S 286.086 9甲拌磷亚砜 19.431 C2H6O2PS 124.982 1 H2O2PS 96.950 8 C3H8O2PS2 170.969 8禾草丹 19.543 C3H6NO 72.044 4 C5H10NO 100.075 7 C7H6Cl 125.015 3艾氏剂 19.573 C7H2Cl5 260.859 4 C7H235Cl437Cl 262.856 4 C12H735Cl337Cl 292.926 7异丙净 19.580 C6H10N5S 184.065 1 C11H20N5 222.171 3 C11H21N5S 255.151 2马拉硫磷 19.630 C2H6O2PS 124.982 1 C4H3O3 99.007 7 C8H13O4 173.080 8甲拌磷砜 19.746 C2H6O2PS 124.982 1 C3H8O2PS2 170.969 8 C5H12O2PS2 199.001 1异丙甲草胺 19.776 C10H12N 146.096 4 C11H16N 162.127 7 C13H17ClNO 238.099 3乙霉威 19.819 C7H5NO3 151.026 4 C11H13NO3 207.089 0 C14H21NO4 267.146 5倍硫磷 19.888 C2H6O2PS 124.982 1 C10H14O3PS 245.039 6 C10H15O3PS2 278.019 5丁苯吗啉 19.971 C7H14NO 128.107 0 C12H15 159.116 8 C20H31NO 301.240 0毒死蜱 19.978 C5H2Cl3NO 196.919 6 C5H3Cl2NO3PS 257.894 0 C9H11Cl2NO3PS 313.956 9 4,4-二氯二苯甲酮 19.991 C7H4ClO 138.994 5 C13H8ClO 215.025 8 C13H8Cl2O 249.994 7吡咪唑 19.991 C10H8N3 170.071 3 C12H11N4 211.097 8 C12H12N4 212.105 6对硫磷 19.998 C2H6O3P 109.004 9 C8H10NO5PS 263.001 2 C10H14NO5PS 291.032 5异氯磷 20.117 C2H6O2PS 124.982 1 C8H9O3PS 216.000 5 C8H9NO5PS 261.993 4氯酞酸甲酯 20.134 C9H3Cl4O3 298.883 1 C9H335Cl337ClO3 300.880 2 C10H635Cl337ClO4 331.898 6氟噻草胺 20.194 C5H2F3N2O2S 210.978 4 C9H10FN 151.079 2 C8H7FN 136.055 7芬螨酯 20.313 C6H5 77.038 6 C6H5O2S 141.000 5 C12H9ClO3S 267.995 5四氟醚唑 20.343 C8H5Cl2 170.976 3 C13H11ClF4N3O 336.052 1 C13H1137ClF4N3O 338.049 7氟咯草酮 20.419 C8H7F3N 174.052 5 C8H4F3NO 187.023 9 C12H10Cl2F3NO 311.008 6十二环吗啉 20.482 C18H35NO 281.271 3 C9H16NO 154.122 6 C15H28NO 238.216 5增效胺 20.552 C9H10NO2 164.070 6 C5H5NO2 111.031 5 C12H20NO2 210.148 9仲丁灵 20.625 C11H14N3O2 220.108 1 C12H16N3O4 266.113 5 C14H19N3O3 277.142 1双苯酰草胺 20.635 C12H8 152.062 1 C13H11 167.085 5 C16H17NO 239.130 5异艾氏剂 20.648 C7H14Cl3 192.937 3 C7H1435Cl237Cl 194.934 4 C7H235Cl437Cl 262.856 4嘧啶磷 20.880 C11H19N3O3PS 304.087 9 C13H24N3O3PS 333.127 1 C12H21N3O3PS 318.103 6异丙乐灵 20.930 C10H12N3O4 238.082 2 C13H18N3O3 264.134 3 C13H18N3O4 280.129 2甲基异柳磷 20.977 C7H5O2 121.028 4 C8H8O4P 199.015 5 C5H2OS 109.982 4吡唑草胺 21.083 C9H10N 132.080 8 C9H12N 134.096 4 C11H12ClNO 209.060 2二甲戊灵 21.176 C9H10N2O 162.078 8 C9H10N3O3 208.071 7 C11H14N3O4 252.097 9异戊乙净 21.189 C8H14N5S 212.096 4 C10H18N5S 240.127 7 C11H21N5S 255.151 2啶斑肟I 21.322 C7H3Cl2N 170.963 7 C13H8ClN2 227.037 1 C13H8Cl2N2 262.005 9甲苯氟磺胺 21.352 C7H7NS 137.029 4 C9H13N2S 181.079 4 C8H7Cl2FNS 237.965 5氟虫腈亚砜 21.362 C8H4Cl2F3N2 254.969 8 C11H4Cl2F3N4S 350.948 0 C12H4Cl2F6N4S 419.943 2乙菌利 21.385 C7H3Cl2NO 186.958 6 C10H7Cl2NO3 258.979 7 C13H11Cl2NO5 331.000 9地胺磷 21.421 CH3NO3PS 139.956 6 C3H7NO3PS 167.987 9 C5H10NO3PS2 226.983 4

续表1

碎片1 碎片2 碎片3分子式 m/z 分子式 m/z 分子式 m/z异柳磷 21.551 C7H4O2 120.020 6 C7H6O4P 184.999 8 C9H10O4P 213.031 1喹硫磷 21.607 C7H6N2 118.052 5 C8H6N2O 146.047 5 C10H8N2 156.068 2三唑醇 21.610 C4H6N3O 112.050 5 C6H5ClO 128.002 3 C8H14N3O 168.113 1氟虫腈 21.620 C11H4Cl2F3N4S 350.948 0 C11H4Cl2F3N4OS 366.942 9 C12H4Cl2F6N4S 419.943 2稻丰散 21.644 C7H5S 121.010 6 C9H11O2PS2 245.993 3 C10H11O3PS2 273.988 2氟丁酰草胺 21.667 C7H7 91.054 2 C11H14NO 176.107 0 C8H5F4O 193.027 1呋霜灵 21.763 C5H3O2 95.012 8 C15H16NO2 242.117 6 C16H15NO3 269.104 6杀螨醚 21.793 C7H6Cl 125.015 3 C7H637Cl 127.012 0 C13H10Cl2S 267.987 5腐霉利 21.816 C6H8O 96.057 0 C13H11Cl2NO2 283.016 1 C13H1135Cl37ClNO2 285.013 4整形醇 21.932 C12H8 152.062 1 C13H8ClO 215.025 8 C15H11ClO3 274.039 1杀扑磷 22.075 C3H5N2O 85.039 6 C2H6O2PS 124.982 1 C5H6O3P 145.006 6双氯氰菌胺 22.198 C8H7Cl2 172.991 9 C11H10ClN2O 221.047 6 C15H18ClN2O 277.110 2丙虫磷 22.211 C7H8OS 140.029 0 C7H9O4PS 219.995 4 C13H21O4PS 304.089 3啶斑肟II 22.274 C7H3Cl2N 170.963 7 C7H3Cl2NO 186.958 6 C13H8Cl2N2 262.005 9苯硫威 22.327 C3H6NO 72.044 4 C7H14NOS 160.079 1 C6H6O 94.041 3氟吡甲禾灵 22.327 C14H7ClNO4 288.003 4 C16H11ClNO4 316.034 7 C16H13ClF3NO4 375.048 0嘧菌胺 22.572 C14H10N3 220.086 9 C14H13N3 223.110 4 C14H12N3 222.102 6丁草胺 22.689 C11H14N 160.112 1 C11H14NO 176.107 0 C16H14O2 238.098 8灭菌磷 22.708 C8H4NO 130.028 7 C12H3O4S 242.974 7 C12H14NO4PS 299.037 6粉唑醇 22.708 C7H4FO 123.024 1 C13H9F2O 219.061 6 C8H7FN3 164.061 9敌草胺 22.927 C7H14NO 128.107 0 C12H11O 171.080 4 C17H21NO2 271.156 7苯线磷 22.951 C8H10O3PS 217.008 3 C10H15NO3PS 260.050 5 C13H22NO3PS 303.105 3己唑醇 22.990 C8H6Cl2N3 213.993 3 C8H635Cl37ClN3 215.990 4 C11H13Cl2O 231.033 8啶氧菌酯 23.050 C10H9O 145.064 8 C16H8F3NO2 303.050 2 C17H12F3NO3 335.076 4三环唑 23.107 C9H7N3S 189.035 5 C8H6N2S 162.024 6 C8H5N2S 161.016 8氟酰胺 23.113 C17H16F3NO2 323.112 8 C8H4F3O 173.020 9 C7H4F3 145.026 0抑霉唑 23.143 C7H3Cl2O 172.955 5 C7H335Cl37ClO 174.952 7 C10H9Cl2O 215.002 5丙硫磷 23.170 C11H15ClO2PS2 308.993 4 C11H5ClO2PS 266.946 5 C9HClO2PS 238.915 2稻瘟灵 23.236 C8H12O2S2 204.027 3 C9H11O3S2 231.014 4 C12H18O4S2 290.064 1丙溴磷 23.282 C6H4BrClO 205.912 9 C6H5BrO3PS 266.887 5 C11H15BrO3PS 336.965 7烯效唑 23.362 C9H6ClO 165.010 2 C11H937ClN3O 236.040 2 C11H9ClN3O 234.042 9狄氏剂 23.369 C7H2Cl5 260.859 4 C7H235Cl437Cl 262.856 4 C10HCl4O 276.872 1 p,p’-滴滴伊 23.395 C14H8Cl2 245.999 8 C14H835Cl37Cl 247.997 0 C14H835Cl337Cl 317.934 6丙草胺 23.428 C11H14NO 176.107 0 C13H16NO 202.122 6 C16H14O2 238.099 3噁草酮 23.651 C6H3Cl2NO 174.958 6 C11H12Cl2N2O 258.032 1 C15H18Cl2N2O3 344.068 9腈菌唑 23.697 C8H6ClN3 179.024 5 C8H5ClN 150.010 5 C12H10ClN4 245.058 9苄氯三唑醇 23.767 C7H5Cl2 158.976 3 C11H1035Cl37ClN3O 272.016 7 C11H10Cl2N3O 270.019 5噻嗪酮 23.820 C7H6N 104.049 5 C7H8N 106.065 1 C8H16N2S 172.102 9氧环唑 23.840 C9H7Cl2O2 216.981 8 C9H735Cl37ClO2 218.978 9 C7H3Cl2O 172.955 5氟硅唑 23.843 C9H9FN3Si 206.054 4 C13H11F2Si 233.059 3 C16H14F2N3Si 314.092 0甲氧丙净 23.886 C8H14N5S 212.096 4 C9H16N5S 226.112 1 C10H18N5OS 256.122 7氟虫腈砜 23.943 C8H4Cl2F3N2 254.969 8 C11HClF5N4O2S 382.937 9 C12H4Cl2F6N4O2S 451.933 1乙嘧酚磺酸酯 23.986 C10H17N4 193.144 8 C10H17N4O3S 273.101 6 C13H24N4O3S 316.156 4醚菌酯 24.042 C8H6N 116.049 5 C6H11O3 131.073 1 C11H12NO3 206.081 2除草醚 24.135 C12H7ClO 202.018 0 C12H7Cl2NO3 282.979 7 C12H735Cl37ClNO3 284.977 0异狄氏剂 24.148 C11H6Cl3 242.953 0 C7H2Cl5 260.859 4 C7H1235Cl437Cl 262.856 4环丙唑醇 24.152 C7H6Cl 125.015 3 C7H4ClO 138.994 5 C10H9ClN3O 222.042 9环丙嘧啶醇 24.274 C8H9O 121.064 8 C12H11N2O2 215.081 5 C13H12N2O2 228.089 3乙滴滴 24.357 C17H19 223.148 1 C18H20 236.155 4 C17H17 221.132 5虫螨腈 24.434 C13H7BrClF3N2 361.942 8 C13H7Br37ClF3N2 363.940 7 C13H6F3N2 247.047 8乙酯杀螨醇 24.616 C7H4ClO 138.994 5 C7H437ClO 140.991 7 C13H9Cl2O 251.002 5倍硫磷亚砜 24.749 C2H6O2PS 124.982 1 C10H15O3PS2 278.019 5 C10H15O4PS2 294.014 4酯菌胺 24.809 C10H1037ClNO2 213.036 9 C10H10ClNO2 211.039 5 C14H14ClNO3 279.065 7乙环唑 24.812 C7H3Cl2O 172.955 5 C7H5Cl2O2 190.966 1 C11H11Cl2O2 245.013 1 p,p’-滴滴滴 24.908 C13H9Cl2 235.007 6 C13H935Cl37Cl 237.004 8 C13H8Cl 199.030 9麦草氟异丙酯 24.955 C7H4ClFN 156.001 1 C12H14ClFNO2 258.069 2 C15H12ClFNO 276.058 6化合物 保留时间/min

续表1

化合物 保留时间/min 35Cl37Cl 237.004 8丙环唑II 26.375 C7H3Cl2O 172.955 5 C7H5Cl2O2 190.966 1 C12H13Cl2O2 259.028 7戊唑醇 26.723 C7H6Cl 125.015 3 C8H7Cl 138.023 1 C12H13ClN3O 250.074 2氟苯嘧啶醇 26.736 C7H4ClO 138.994 5 C13H9ClFO 235.032 0 C17H12ClFN2O 314.061 7增效醚 27.181 C9H9O2 149.059 7 C11H12O2 176.083 2 C11H13O3 193.085 9苯酰菌胺 27.360 C8H5Cl2O 186.971 2 C8H535Cl37ClO 188.968 3 C11H10Cl2NO 242.013 4氟环唑 27.370 C8H6ClN2 165.021 4 C9H7ClN3 192.032 3 C13H8F 183.060 5拌种咯 27.649 C11H6Cl2N2 235.990 3 C11H635Cl37ClN2 237.987 4 C11H6ClN2 201.021 4异狄氏剂酮 27.669 C11H8Cl5 314.906 3 C11H835Cl437Cl 316.903 4 C11H735Cl337Cl 280.926 7糠菌唑 27.868 C7H3Cl2O 172.955 5 C7H335Cl37ClO 174.952 7 C8H6Br35Cl37ClN3 294.908 7溴螨酯 28.077 C13H9Br2O 338.901 5 C12H9Br2O2 342.897 6 C7H4BrO 182.944 0氟唑菌酰胺 28.266 C6H5F2N2O 159.036 4 C12H6F3N 221.044 7 C18H12F5N3O 381.089 5联苯肼酯 28.279 C17H20N2O3 300.146 8 C14H14N2O3 258.099 9 C11H10N 156.080 8联苯菊酯 28.296 C14H13 181.101 2 C13H9 165.069 9 C13H10 166.077 7甲氧滴滴涕 28.349 C14H12O2 212.083 2 C15H15O2 227.106 7 C16H15ClO2 274.075 5乙螨唑 28.568 C21H23F2NO2 359.169 1 C19H18F2NO2 300.119 4 C18H16F2NO 330.130 0吡螨胺 28.591 C7H8ClN2O 171.032 0 C17H21ClN3O 318.136 8 C18H24ClN3O 333.160 2三氯杀螨砜 28.989 C6H4ClOS 158.966 6 C6H2Cl3OS 226.888 6 C12H635Cl337ClO2S 355.880 8杀螺吗啉 30.376 C13H9 165.069 9 C18H12 228.093 4 C19H15 243.116 8噁唑禾草灵 31.000 C13H8ClNO3 261.018 7 C15H11ClNO3 288.042 2 C18H16ClNO5 361.071 2哒螨灵 31.749 C9H9 117.069 9 C11H15 147.116 8 C15H18ClN2OS 309.092 3喹禾灵 33.577 C16H12ClN2O2 299.058 2 C19H17ClN2O4 372.087 1 C16H1237ClN2O2 301.055 7氟氰戊菊酯I 33.811 C11H13F2O 199.092 9 C8H7F2O 157.045 9 C14H11NO2 225.078 4氟氰戊菊酯II 34.141 C11H13F2O 199.092 9 C8H7F2O 157.045 9 C14H11NO2 225.078 4氟硅菊酯 34.191 C7H16FO2Si 179.088 7 C8H11OSi 151.057 4 C15H15FOSi 258.087 1氰戊菊酯 35.060 C13H9O 181.064 8 C7H6Cl 125.015 3 C14H11NO2 225.078 4丙炔氟草胺 35.077 C15H12FN2O3 287.082 6 C18H15FN2O3 326.106 1 C19H15FN2O4 354.101 0唑虫酰胺 37.147 C7H8ClN2O 171.032 0 C14H13NO 211.099 2 C21H22ClN3O 383.139 5 35Cl37Cl 237.004 8噁霜灵 25.071 C10H13NO 163.099 2 C9H10N 132.080 8 C12H13N2O3 233.092 1乙硫磷 25.167 H2O2PS 96.950 5 C2H6O2PS 124.982 1 C5H12O2PS3 230.973 2麦锈灵 25.187 C6H4I 202.935 2 C7H4IO 230.930 1 C13H10INO 322.980 2灭锈胺 25.422 C8H7O 119.049 1 C14H10O2 210.067 5 C17H19NO2 269.141 0三唑磷 25.618 C8H7N3O 161.058 4 C10H10N3 172.086 9 C8H8N3O3PS 257.001 8呋酰胺 25.751 C9H10N 132.080 8 C12H12NO 186.091 3 C13H14NO3 232.096 8三硫磷 25.864 C7H6ClS 156.987 3 C6H12ClOS2 199.001 1 C10H14ClO2PS2 295.985 6苯霜灵 25.957 C10H14N 148.112 1 C12H16NO2 206.117 6 C18H20NO 266.153 7苯虫醚I 25.990 C12H10O2 186.067 5 C15H13O2 225.091 0 C18H20O4 300.135 6敌瘟磷 25.993 C6H5S 109.010 6 C6H6O2PS 172.982 1 C8H10O2PS 201.013 4喹氧灵 26.010 C15H8FNO 237.058 4 C15H8ClFNO 272.027 3 C15H8Cl2FNO 306.996 1苯腈磷 26.023 C6H6O2P 141.010 0 C6H6OPS 156.987 1 C8H10O2P 169.041 3硫丹硫酸酯 26.046 C535Cl537Cl 271.809 6 C535Cl437Cl2 273.806 7 C9H6Cl6O4S 419.811 2氟草敏 26.139 C12H9ClF3N3O 303.038 1 C12H937ClF3N3O 305.035 5 C7H4F3 145.026 0丙环唑I 26.139 C7H3Cl2O 172.955 5 C7H5Cl2O2 190.966 1 C12H13Cl2O2 259.028 7苯虫醚II 26.235 C12H10O2 186.067 5 C15H13O2 225.091 0 C18H20O4 300.135 6 p,p’-滴滴涕 26.245 C13H9 165.069 9 C13H9Cl2 235.007 6 C13H9碎片1 碎片2 碎片3分子式 m/z 分子式 m/z 分子式 m/z倍硫磷砜 24.971 C2H6O2PS 124.982 1 C10H15O3PS 246.047 4 C10H15O5PS2 310.009 3 o,p’-滴滴涕 25.014 C13H9 165.069 9 C13H9Cl2 235.007 6 C13H9

2 结果与分析

2.1 提取条件的选择

依据国家相关标准中涉及的农药目录,结合我国果蔬种植常用农药种类,选择234 种适合GC分析农药作为目标分析化合物,包含了大多数农药,包含有机磷类、有机氯类、拟除虫菊酯类、苯氧羧酸类、三唑类和酰胺类农药,种类多且极性差异较大,因此选择合适的提取溶剂尤为重要。采用甲醇为溶剂时,提取的色素少,但回收率为0%~56%。采用乙酸乙酯提取,有些有机磷农药如七氯,回收率小于70%。传统的QuEChERS采用乙腈为提取溶剂,乙腈的溶解性好、渗透力强,适合提取的农药极性范围广,对大多数农药的提取效率高。本实验考察了加入氯化钠和乙酸缓冲盐包对234 种化合物的提取效率的影响,以在苹果基质中添 加量为50 μg/kg的回收率作为考察指标。结果显示,加入氯化钠,一些稳定性差的农药回收率低,农药回收率在70%~120%之间的有183 种,其结果与基质的pH值有关,加入乙酸缓冲盐后农药如百菌清回收率从75%提高到86%,敌敌畏回收率由55%提高到75%,甲胺磷回收率从73%提高到89%,所有农药的回收率均在70%~120%之间,满足检测要求。样品中加入乙酸缓冲盐形成的缓冲体系使基质pH值在整个实验过程中保持在5.0~6.0之间,该体系能有效防止对酸碱敏感农药的降解,适合于多种果蔬基质。由于本实验涉及的农药种类较多,因此本实验选择乙腈作为提取溶剂,加乙酸缓冲盐包调节pH值。乙酸缓冲盐体系盐包中含有无水MgSO4,在提取过程中吸水会大量放热,有些有机磷(如甲胺磷、对硫磷和杀螟硫磷等)农药化学性质不稳定,高温易分解,回收率小于70%,而放入冰水浴中,这些化合物回收率大于75%,满足要求。因而在加入乙酸缓冲盐体系盐包后把提取样品的离心管迅速放入冰水浴中2 min,减少热稳定性差农药的回收率。

2.2 净化条件的选择

果蔬基质中含有脂类、色素、糖类和有机酸等,这些物质在提取过程中会和目标物一起提出。如果不进一步净化,目标物会受到干扰而影响定性定量结果。本实验比较QuEChERS净化包和m-PFC柱净化。QuEChERS净化包起主要作用的PSA、十八烷基键合硅胶吸附剂(C18)和石墨化碳黑(graphitized carbon black,GCB)。其中PSA中氨基官能团可与一些酸性基团反应,可以除去极性的有机酸,以及一些糖类和脂类;C18是一种多孔吸附剂,起非极性的物理吸附作用,可以用来去除脂类和固醇。但PSA和C18对色素的净化效果均不能达到要求。GCB能够对果蔬中叶绿素及极性小分子干扰物质有很好的吸附效果,但是GCB非常容易吸附平面结构的目标物,如拟虫菊酯类农药有很强吸附性导致目标物回收率偏低。m-PFC柱中除PSA外,还添加了一定量的MWCNTs。MWCNTs是 一种新型纳米材料,具有极高的强度、极大的韧性和较大的比表面积,对色素、脂肪等干扰物质有特殊的选择性。该材料为管状结构,具有独特的理化性能,吸附性能与GCB不同,机械强度高、耐酸、碱能力强,具有更强的吸附和净化能力。以韭菜样品为例,当添加量为50 μg/kg时,采用m-PFC柱净化和QuEChERS净化包净化,分别对234 种农药回收率进行检测。通过比较可以看出:采用m-PFC柱净化回收率在70%~120%之间的农药大于QuEChERS净化包净化,见表2。采用m-PFC柱净化,所有农药回收率在73.2%~122.4%之间,相对标准偏差(relative standard deviation,RSD)低于10.8%;采用QuEChERS净化包净化,所有农药回收率在63.2%~123.5%之间,RSD低于12.4%。2 种方法的回收率有差异,主要是QuEChERS净化包GCB中吸附作用,所以m-PFC柱净化较QuEChERS净化包净化效率高且对目标物回收率基本无影响。对于色素严重的复杂基质(如韭 菜、菠菜、油菜等),采用m-PFC小柱(复杂基质),和m-PFC小柱(简单基质)相比,将15 mg MWCNTs调整为25 mg MWCNTs,其他材料未变,净化效果更好,所有农药回收率在72.8%~121.3%之间,RSD小于10.4%,回收率能满足筛查要求且和m-PFC小柱(简单基质)无太大差别,但能降低对分析仪器的污染和损害。实验表明,一定量PSA和MWCNTs的配合使用能有效避免基质中杂质的干扰,提高目标物的回收率。同时m-PFC法净化对每个样品的前处理时间可控制在10 min以内,而QuEChERS净化包净化还需要移取上清液后再次离心,每个样品的前处理时间较长。由此可见,m-PFC法可以在较短的时间内准确完成果蔬样品中农药残留的提取净化工作,可大幅度提高前处理速率和效率。所以本实验选择m-PFC柱净化。

表2 韭菜中234 种农药在不同净化方法时的加标回收率(50 μg kg)
Table 2 Recoveries of 234 pesticides in spiked Chinese leek samples cleaned up by different purifification methods (50 μg kg)

m-PFC小柱(复杂基质)<70% 15 0 0 70%~120% 210 231 232>120% 9 3 2回收率农药数量QuEChERS净化包m-PFC小柱(简单基质)

2.3 定性筛查及确证

应用表1建立的谱库进行检索时,化合物的精确质量数偏差、保留时间偏差、同位素分布和同位素丰度比是影响定性判定的主要因素。根据欧盟SANTE/11945/2015[39],使用高分辨质谱确证时,至少需1 个精 确质量数的离子和1 个碎片离子。

定性软件中调用创建的PCDL精确质量数据库进行目标化合物的检索,检索参数如下:质量提取窗口25×10-6,质量偏差5×10-6;保留时间提取窗口0.40 min,保留时间偏差0.15 min;信噪比3;匹配要求:离子信息3 个;共流出比较:0.15 min。根据检索的参数进行打分,检出离子的得分平均值即为该化合物的综合得分,规定化合物的得分大于60且至少3 个离子检出,判别该化合物为阳性。应用本研究建立的谱库,234 种目标化合物均能被准确确证。苹果基质样品234 种的总离子流图(图1a),蕴含着丰富的化学信息,但看不出目标物的色谱峰;苹果基质样品的提取离子流图(图1b),能够很明显看出苹果基质添加234 种目标物的色谱峰,定性和定量分析软件就是根据该信息进行分析,从而达到确认目标物和准确定量的目的。说明GC-QTOF-MS能够从复杂基质中提取有用的信息,其在高通量筛查中具有优势。

图1 苹果基质中添加量为5500 μgg/kg 234 种农药的总离子流图(a)和提取离子流图(bb)
Fig. 1 Total ion current chromatogram (a) and extracted ion chromatograms (b) of 234 pesticides spiked into apple matrix at 50 μg/kg

2.4 基质效应

采用GC-MS法时,基质效应(matrix effect,ME)一般归因于目标物经由热进样口向色谱柱传输过程中由于基质的参与,减少了热不稳定目标物的分解,或者由于基质屏蔽了进样口的活性位点,从而减少了极性目标物被活性位点吸附,从而影响成分复杂样品定性定量分析结果的重现性和准确度。ME评价方法:ME/%=B/A×100,A为在纯溶剂中农药目标物的信号峰面积,B为在样品基质液中添加相同含量的目标物信号峰面积,ME在70%以下认为存在基质抑制效应,在80%~120%之间则认为ME不明显,在120%以上认为存在强基质增强效应[40]。本实验考察12 种典型果蔬样品(白菜、芹菜、番茄、黄瓜、菠菜、韭菜、油菜、柑橘、梨、苹果、葡萄、橙子)的ME,其中联苯菊酯、氰戊菊酯和嘧菌酯在柑橘、橙子、韭 菜和菠菜的ME大于120%,表现为基质增强效应;在其余的8 种基质中为80%~120%之间,ME不明显。氟氰戊菊酯、溴螨酯、腈菌唑和虫螨腈在芹菜和黄瓜的ME大于120%,表现为基质增强效应;在其余的10 种基质ME在80%~120%之间,ME不明显。其他化合物在12 种基质中ME在80%~120%之间,ME不明显。234 种目标物在12 种基质中无基质抑制效应。因此本实验采用空白基质溶液配制标准曲线法进行定量抵消ME的影响,这样不仅前处理步骤简单,定量更准确。

2.5 线性范围、检出限和回收率

以12 种典型基质(白菜、芹菜、番茄、黄瓜、菠菜、韭菜、油菜、柑橘、梨、苹果、葡萄、橙子)进行分析,配制空白基质标准曲线溶液为0.005、0.02、0.05、0.1、0.5 μg/mL,以化合物的相应含量(X)为横坐标,对应峰面积(Y)为纵坐标,绘制标准曲线。各目标化合物在5~500 μg/kg范围的线性关系良好,相关系数(R2)均大于0.990。采用空白样品添加的方式考察方法中234 种农药的检出限均在5~20.0 μg/kg之间,符合多数农药残留的分析要求。为考察方法的准确性,分别在阴性样品基质中添加234 种化合物的混合标准溶液,添加量分别为10、50、100 μg/kg,在优化的条件下进行测定,每个添加水平做6 个平行实验。结果显示,234 种化合物在3 个添加水平下12 种典型果蔬样品的平均加标回收率分别为73.2%~124.8%、75.5%~122.6%和74.8%~121.7%,平均RSD分别为2.4%~13.2%、2.8%~11.4%和2.2%~10.5%。表明该方法回收率和精密度满足国家标准关于农药残留检测方法要求[41],其中韭菜和苹果基质中234 种化合物的相关系数、检出限、平均加标回收率和平均RSD见表3。

2.6 实际样品的测定结果

用1.3节样品前处理方法,对市售的200 例样品(白菜、芹菜、番茄、黄瓜、菠菜、韭菜、油菜、柑橘、梨、苹果、葡萄、橙子)进行检测,其中158 例样品检出农药残留,其中芹菜、韭菜、菠菜、葡萄、柑橘等样品的检出率较高;农药检出率较高的为毒死蜱、苯醚甲环唑、腐霉利、联苯菊酯、甲霜灵、虫螨腈、抑霉唑、哒螨灵、二甲戊灵、丙溴磷、乙螨唑、戊唑醇化合物。其中韭菜样品中有4 批毒死蜱和腐霉利超出食品中农药最大残留限量;芹菜样品中有2 批毒死蜱超出食品中农药最大残留限量;柑橘样品中3 个批次丙溴磷和抑霉唑超过食品中农药最大残留限量;其余化合物均未超过食品中农药最大残留限量[41]。苹果中毒死蜱提取离子流图(图2a),3 个碎片离子能够确认毒死蜱,且保留时间和 PCDL库中接近。毒死蜱标准物质(图2b)和苹果样品中毒死蜱(图2c)的质谱图显示,其质量误差、碎片离子分子式和相对离子丰度进一步确认了苹果中毒死蜱存在。经过实际样品的验证,该方法也适用于草莓、桃、西兰花、金针菇等果蔬中234 种农药残留的检测,同时也为果蔬中农药残留测定提供了靶向性和针对性。

表3 韭菜和苹果中234 种农药的相关系数、检出限、加标回收率和相对标准偏差( =6)
Table 3 Correlation coeffificients (R2 ) , limits of detection, spiked recoveries and RSDs of 234 pesticides in Chinese leek and apple ( = 6)

韭菜回收率/%(RSD/%)10 μg/kg 50 μg/kg 100 μg/kg 10 μg/kg 50 μg/kg 100 μg/kg化合物苹果R2 检出限/(μg/kg)回收率/%(RSD/%) R2 检出限/(μg/kg)甲胺磷 0.993 1 5 72.4(8.1) 76.2(6.4) 78.4(7.1) 0.998 6 5 73.4(9.1) 77.0(6.2) 78.1(5.5)敌敌畏 0.995 2 5 75.6(5.9) 78.9(6.8) 80.4(5.6) 0.997 3 5 73.7(6.2) 74.3(9.4) 79.2(9.4)敌草腈 0.997 7 5 82.2(8.2) 79.6(5.2) 80.5(3.9) 0.998 6 5 74.2(3.3) 78.3(7.4) 79.7(5.6)茵草敌 0.998 0 10 78.5(6.8) 84.6(5.4) 88.3(5.1) 0.999 5 10 80.2(3.3) 83.1(8.4) 88.4(5.5)烯丙酰草胺 0.998 5 10 98.9(4.3) 97.6(6.9) 93.8(4.9) 0.992 5 10 99.5(6.9) 92.6(4.2) 95.2(4.0)速灭磷 0.998 7 20 — 108.6(4.5) 98.5(6.8) 0.998 4 20 — 104.0(4.0) 97.6(6.3)灭草敌 0.998 5 10 98.7(8.5) 98.4(6.9) 89.5(6.6) 0.993 8 5 95.5(6.2) 95.4(4.4) 88.6(7.5)氯唑灵 0.998 1 5 108.9(5.4) 89.2(3.9) 108.7(6.9) 0.999 3 5 102.4(3.3) 87.5(5.4) 103.5(6.8)氯苯甲醚 0.999 3 5 96.7(6.9) 87.7(3.6) 98.5(3.7) 0.998 5 5 94.7(9.3) 84.2(5.5) 94.2(6.3)庚烯磷 0.999 4 5 108.9(5.9) 107.4(8.2) 92.4(9.5) 0.998 0 5 105.5(8.5) 106.4(6.8) 88.3(5.8)燕麦酯 0.998 5 10 106.4(8.3) 94.8(5.6) 95.9(6.9) 0.998 2 5 108.7(3.9) 94.6(3.7) 99.8(6.9)氟啶虫酰胺 0.997 6 10 79.5(4.9) 88.3(5.9) 108.5(3.9) 0.998 4 5 77.9(6.3) 87.2(7.3) 103.3(8.0)四氯硝基苯 0.998 5 5 105.9(5.8) 106.7(8.2) 89.6(3.9) 0.998 3 5 106.3(6.2) 109.3(9.5) 86.2(5.7)毒草胺 0.998 4 10 108.5(4.3) 78.5(6.9) 98.7(6.8) 0.997 4 5 107.9(4.8) 79.4(6.9) 98.5(6.2)残杀威 0.998 4 5 98.7(6.8) 117.8(6.4) 98.5(6.9) 0.998 2 5 94.4(7.3) 110.1(8.5) 97.1(5.5)灭线磷 0.995 5 10 106.8(3.4) 89.5(5.2) 107.8(6.4) 0.998 5 10 102.5(4.3) 89.7(5.6) 103.2(6.4)氟氯氢菊脂 0.998 5 5 108.4(3.5) 82.4(7.6) 108.4(6.3) 0.994 2 5 108.6(3.8) 80.5(6.2) 104.1(5.2)甲基苯噻隆 0.995 4 20 — 86.9(7.6) 98.7(5.8) 0.996 2 20 — 83.5(9.1) 93.5(9.2)杀虫脒 0.998 4 5 106.4(6.5) 85.5(6.9) 107.2(6.8) 0.998 6 5 105.2(7.3) 80.4(9.5) 109.1(7.4)去乙基阿特拉津 0.994 4 5 108.6(3.9) 88.4(5.9) 108.5(6.4) 0.995 1 5 106.5(7.3) 85.6(9.2) 104.2(7.1)2,6-二氯苯甲酰胺 0.998 1 5 96.4(5.6) 98.4(6.9) 98.4(3.9) 0.996 3 5 95.2(5.3) 93.3(8.1) 94.6(5.4)噁虫威 0.997 5 10 84.3(3.8) 78.9(5.7) 109.5(7.4) 0.994 3 5 83.1(5.2) 78.3(9.4) 104.5(9.6)氟乐灵 0.997 5 10 96.8(6.5) 82.5(4.8) 86.9(6.4) 0.992 7 10 92.4(4.8) 75.6(9.2) 84.8(6.8)乙丁氟灵 0.998 3 10 95.0(4.8) 107.2(9.3) 114.4(5.2) 0.996 2 10 98.0(7.1) 102.5(6.7) 114.4(3..9)硫线磷 0.992 2 20 — 100.8(5.5) 105.1(7.4) 0.998 4 20 — 102.2(4.3) 108.7(5.2)治螟磷 0.998 4 5 98.2(4.9) 93.5(5.9) 94.7(5.8) 0.998 8 5 94.3(7.4) 103.5(4.4) 101.7(5.7)猛杀威 0.998 5 5 84.6(8.3) 75.8(9.2) 94.0(8.1) 0.998 3 5 88.5(3.4) 82.8(5.6) 90.0(7.4)甲拌磷 0.998 3 5 104.8(6.6) 109.5(4.5) 108.2(7.2) 0.995 9 5 98.6(2.4) 99.5(9.7) 105.9(7.5)α-六六六 0.998 4 20 — 89.2(5.7) 102.8(4.5) 0.993 2 20 — 88.2(3.5) 101.5(5.4)西玛通 0.995 2 5 92.5(6.6) 90.4(4.2) 94.5(5.3) 0.996 4 5 92.5(6.6) 90.4(4.2) 94.5(5.3)五氯甲氧基苯 0.992 5 5 98.2(3.9) 98.7(8.2) 98.5(8.4) 0.993 1 5 103.4(4.9) 104.2(5.2) 98.2(7.4)乐果 0.998 3 10 108.6(4.7) 95.6(9.6) 94.2(8.3) 0.998 2 10 103.4(4.5) 103.4(9.7) 102.2(5.3)乙氧喹啉 0.998 4 5 108.2(7.8) 97.4(7.5) 107.4(3.9) 0.997 4 5 104.6(7.1) 105.4(5.2) 101.4(3.3)西玛津 0.998 5 5 118.4(5.8) 109.4(6.4) 107.5(3.8) 0.993 4 5 109.9(7.5) 112.5(4.5) 103.3(5.8)扑灭通 0.996 1 5 104.5(7.8) 110.6(9.6) 108.8(9.3) 0.997 4 5 102.9(5.4) 98.6(5.9) 107.7(8.2)绿谷隆 0.998 3 5 108.2(5.9) 99.8(5.9) 97.6(5.8) 0.997 2 5 101.1(5.7) 94.4(8.2.) 95.5(4.9)莠去津 0.998 4 5 102.3(4.4) 105.5(8.1) 107.3(5.2) 0.995 4 5 105.3(6.7) 105.5(4.6) 107.3(8.8)β-六六六 0.996 1 10 104.2(4.8) 105.6(4.7) 107.5(8.3) 0.997 8 10 101.2(5.7) 100.1(7.2) 105.4(3.5)异噁草酮 0.998 4 20 — 97.5(5.3) 103.4(7.5) 0.998 3 20 — 90.5(5.3) 105.8(4.9)扑灭津 0.998 7 5 97.8(6.5) 108.4(4.8) 108.3(6.4) 0.998 4 5 102.3(5.2) 105.4(9.4) 107.3(3.9)特丁通 0.998 8 5 105.7(4.8) 102.4(5.8) 104.8(3.9) 0.998 8 5 107.2(8.4) 96.9(7.6) 97.3(5.5)γ-六六六 0.998 6 10 98.7(5.7) 96.8(4.3) 98.7(6.8) 0.995 5 10 106.3(7.4) 98.4(3.2) 105.4(2.3)灭害威 0.998 5 5 108.4(7.2) 97.4(5.9) 96.9(6.8) 0.998 5 5 102.5(9.8) 78.4(5.1) 98.2(5.8)环莠隆 0.999 3 10 110.3(8.1) 97.2(9.4) 96.3(7.3) 0.998 5 5 104.8(7.2) 98.5(4.9) 98.6(5.7)五氯硝基苯 0.997 3 5 106.2(4.5) 105.8(5.6) 99.3(4.5) 0.996 3 5 102.2(9.2) 109.8(6.2) 111.3(5.3)五氯苯甲腈 0.998 6 5 99.6(7.8) 94.5(8.2) 92.6(10.7) 0.998 4 5 95.1(5.3) 100.4(9.8) 97.6(9.2)杀螟腈 0.998 3 5 106.4(8.2) 100.7(6.2) 110.5(4.7) 0.998 7 5 104.3(8.2) 101.3(5.8) 105.6(8.8)咯喹酮 0.998 6 5 98.9(5.5) 97.8(5.9) 98.6(4.6) 0.998 4 5 95.4(7.8) 92.6(8.8) 95.2(9.9)草达津 0.994 3 5 101.4(5.6) 108.5(4.4) 102.8(4.2) 0.998 4 5 111.5(8.5) 103.5(5.6) 106.7(5.2)地虫硫磷 0.998 5 5 106.8(4.4) 107.8(5.2) 108.5(5.9) 0.996 3 5 107.8(6.9) 104.6(5.4) 113.4(8.8)胺丙畏 0.998 6 5 82.5(6.8) 84.3(7.8) 85.5(8.5) 0.993 4 5 78.5(9.7) 78.8(6.4) 82.6(7.3)炔苯酰草胺 0.993 6 5 80.4(6.4) 79.8(7.5) 84.3(5.6) 0.998 5 5 75.6(7.8) 73.8(8.1) 78.8(5.4)嘧霉胺 0.998 4 5 82.5(5.1) 90.1(6.2) 92.4(5.3) 0.999 4 5 82.5(5.4) 89.8(6.6) 89.7(5.5)

续表3

回收率/%(RSD/%)10 μg/kg 50 μg/kg 100 μg/kg 10 μg/kg 50 μg/kg 100 μg/kg二嗪磷 0.994 5 5 92.2(6.2) 93.5(4.8) 98.5(3.7) 0.998 1 5 88.5(6.4) 82.6(7.3) 93.7(4.1)乙拌磷 0.998 4 10 102.5(7.2) 105.4(6.3) 98.9(5.9) 0.999 1 10 92.6(5.8) 93.8(4.4) 95.6(3.5)δ-六六六 0.998 6 5 108.2(3.6) 108.2(5.1) 98.8(8.1) 0.998 1 5 105.4(7.5) 105.5(4.3) 98.6(7.8)仲丁通 0.998 9 5 96.8(8.2) 99.6(5.6) 90.3(4.9) 0.997 3 5 95.4(6.5) 95.5(4.6) 88.7(7.5)氨氟灵 0.997 7 20 — 87.5(7.4) 103.1(8.3) 0.998 7 20 — 87.5(7.4) 103.1(8.3)百菌清 0.995 5 5 85.6(7.5) 86.5(5.8) 95.4(5.5) 0.998 4 5 93.7(9.1) 84.5(6.5) 93.5(7.6)兹克威 0.998 4 10 102.5(5.8) 104.5(2.8) 94.1(7.2) 0.999 6 10 106.8(8.6) 106.3(6.5) 92.5(7.8)野麦畏 0.993 3 5 108.4(3.8) 101.4(4.5) 103.5(5.8) 0.998 5 5 104.7(7.6) 89.6(5.8) 98.8(8.5)氯唑磷 0.995 4 5 85.7(8.5) 95.4(4.3) 106.5(7.2) 0.998 5 5 88.2(5.3) 87.2(7.4) 101.5(5.8)氟虫脲 0.998 1 5 105.8(7.5) 105.9(8.5) 106.8(5.3) 0.998 6 5 101.5(6.2) 108.8(9.2) 101.7(5.5)丁基嘧啶磷 0.997 2 5 107.5(5.9) 84.8(3.5) 103.9(5.8) 0.998 5 5 105.4(8.5) 76.7(9.2) 93.5(6.2)解草嗪 0.998 4 5 104.8(7.5) 115.4(3.9) 101.8(5.8) 0.999 2 5 94.4(9.5) 112.2(8.3) 97.5(5.4)安硫磷 0.994 2 20 — 89.5(6.8) 109.3(4.9) 0.998 7 10 108.5(5.1) 87.5(7.6) 105.4(8.7)五氯苯胺 0.994 3 5 108.5(4.7) 86.5(4.5) 107.8(8.9) 0.999 4 5 101.5(6.8) 79.4(9.4) 102.8(7.6)氯硫酰草胺 0.997 5 5 96.8(6.4) 87.9(5.4) 97.6(5.8) 0.998 5 5 96.3(5.5) 83.4(9.3) 93.3(7.6)敌稗 0.995 4 5 105.6(2.9) 85.6(5.9) 108.6(4.5) 0.999 1 5 105.8(5.6) 88.2(8.6) 109.3(5.2)环丙津 0.997 6 5 109.7(4.9) 86.8(3.5) 101.8(4.5) 0.998 4 5 106.7(7.2) 85.2(9.1) 104.3(7.2)除线磷 0.994 7 5 76.5(5.2) 81.4(7.2) 82.3(5.4) 0.998 1 5 81.5(4.9) 84.4(5.3) 90.5(4.9)二甲草胺 0.993 1 10 79.5(6.8) 79.2(10.4) 84.1(6.8) 0.994 0 10 75.5(6.8) 80.4(6.5) 84.1(7.8)二甲吩草胺 0.994 3 10 86.3(5.9) 82.8(4.9) 95.3(3.9) 0.998 9 10 84.3(9.5) 86.4(7.3) 89.3(6.3)溴丁酰草胺 0.998 9 10 108.4(3.9) 101.8(3.2) 96.7(5.9) 0.995 6 10 106.5(6.3) 104.6(5.9) 100.2(4.3)呋嘧醇 0.997 4 20 — 85.4(6.3) 88.5(6.8) 0.998 2 20 — 82.4(5.3) 86.6(7.2)麦穗宁 0.998 3 5 84.8(7.5) 86.4(9.4) 98.4(7.5) 0.998 5 5 79.7(9.3) 88.3(5.2) 94.3(5.7)乙草胺 0.995 5 10 105.1(5.1) 87.8(6.4) 94.5(2.4) 0.998 5 10 105.1(5.1) 87.8(6.4) 94.5(2.4)甲基对硫磷 0.994 7 5 97.5(6.4) 96.5(5.8) 101.5(6.2) 0.998 9 5 92.3(6.7) 93.2(6.8) 101.6(5.7)甲基毒死蜱 0.996 4 10 107.2(5.8) 109.1(7.7) 101.5(8.2) 0.998 3 10 103.2(6.3) 105.1(7.4) 111.5(6.8)乙烯菌核利 0.998 9 5 98.9(6.7) 88.4(6.8) 97.6(4.5) 0.996 5 5 96.7(6.8) 87.6(5.5) 95.3(3.7)特草灵 0.994 5 20 — 102.5(4.6) 95.7(5.3) 0.992 1 20 — 101.5(4.6) 91.7(5.3)甲基立枯磷 0.998 8 10 75.4(4.2) 92.4(4.1) 106.4(4.3) 0.991 4 10 72.4(4.2) 93.4(4.1) 101.4(4.3)七氯 0.998 4 5 79.3(9.4) 82.6(7.7) 81.4(6.1) 0.997 6 5 79.5(9.4) 80.5(7.7) 82.5(6.1)四氟苯菊酯 0.998 8 20 — 96.7(6.1) 86.3(7.3) 0.994 2 20 — 95.5(6.1) 81.0(7.3)甲草胺 0.998 3 10 95.5(6.3) 98.6(7.5) 109.2(5.8) 0.993 2 10 95.1(3.8) 98.4(7.5) 107.2(5.8)莠灭净 0.999 4 5 94.3(4.5) 98.7(6.3) 95.6(3.2) 0.994 3 5 91.4(4.5) 92.3(6.3) 97.2(6.2)灭草环 0.999 2 5 107.6(6.3) 104.1(6.6) 96.5(7.3) 0.999 2 5 106.6(8.3) 105.1(7.6) 93.8(7.8)扑草净 0.995 4 5 96.1(4.3) 97.3(8.5) 84.2(6.1) 0.998 1 5 94.1(8.3) 95.3(6.5) 80.2(9.1)甲霜灵 0.996 2 10 105.6(5.7) 109.2(5.1) 97.4(5.3) 0.999 5 5 108.6(5.1) 102.2(6.4) 95.4(5.2)八氯二丙醚 0.998 4 5 79.8(11.1) 109.1(7.3) 96.3(5.5) 0.998 8 5 79.4(10.3) 103.1(5.3) 96.8(3.9)苄草丹 0.997 1 5 86.4(9.1) 82.4(9.3) 104.3(6.1) 0.999 1 5 83.4(5.1) 79.4(9.3) 106.3(9.1)坪草丹 0.994 3 5 82.8(8.6) 105.8(5.1) 96.2(8.3) 0.999 5 5 87.4(6.5) 102.4(3.8) 98.8(6.8)特丁净 0.998 7 5 84.1(7.2) 94.3(6.4) 107.5(6.6) 0.997 7 5 88.2(3.8) 97.9(5.6) 105.4(6.9)氟硫草定 0.998 0 20 — 118.1(4.4) 117.2(7.1) 0.993 4 20 — 114.5(7.9) 113.6(5.8)杀螟硫磷 0.993 6 5 111.6(7.7) 103.8(7.9) 92.1(9.2) 0.995 4 5 113.2(5.8) 106.4(6.3) 97.8(6.8)除草定 0.994 5 5 97.2(9.1) 94.2(6.3) 107.4(8.5) 0.997 5 5 95.4(8.2) 96.4(3.9) 105.6(4.9)利谷隆 0.998 9 5 101.3(5.3) 84.4(4.5) 105.6(7.7) 0.998 6 5 109.3(7.2) 89.5(7.8) 106.6(3.8)甲基嘧啶磷 0.994 2 5 85.5(4.6) 90.7(2.8) 96.9(7.2) 0.999 4 5 86.8(3.7) 95.4(2.9) 96.5(6.2)戊草丹 0.998 4 10 97.5(9.2) 103.4(7.5) 96.6(7.7) 0.998 2 10 96.5(6.2) 109.2(8.5) 98.6(3.6)乙氧呋草黄 0.998 1 5 81.6(9.5) 92.3(3.1) 96.5(5.2) 0.998 5 5 81.9(5.5) 92.8(3.1) 94.5(5.2)甲拌磷亚砜 0.996 5 5 90.4(4.3) 97.2(6.3) 104.2(6.3) 0.997 3 5 92.5(4.3) 98.6(5.3) 100.2(6.3)禾草丹 0.998 5 5 94.5(6.6) 83.7(9.8) 103.9(8.1) 0.994 7 5 94.8(8.6) 83.7(8.8) 107.9(8.1)艾氏剂 0.997 4 20 — 95.3(4.2) 108.5(7.1) 0.998 5 20 — 97.2(6.2) 104.5(7.1)异丙净 0.994 2 5 87.5(4.6) 104.7(3.8) 96.3(8.0) 0.998 7 5 86.5(4.5) 107.6(5.8) 96.9(4.4)马拉硫磷 0.996 4 20 — 103.3(4.3) 96.1(7.3) 0.994 2 20 — 105.4(3.3) 93.1(7.3)甲拌磷砜 0.998 4 5 102.3(9.6) 94.4(6.2) 109.1(4.2) 0.995 3 5 105.7(9.6) 98.6(3.2) 103.1(4.2)异丙甲草胺 0.998 8 20 — 92.5(5.3) 105.5(7.2) 0.993 5 20 — 99.4(7.3) 102.5(4.2)乙霉威 0.998 5 5 98.2(7.3) 95.8(7.6) 113.4(7.2) 0.998 3 5 100.4(6.5) 97.7(5.8) 119.4(3.9)韭菜化合物苹果R2 检出限/(μg/kg)回收率/%(RSD/%) R2 检出限/(μg/kg)

续表3

回收率/%(RSD/%)10 μg/kg 50 μg/kg 100 μg/kg 10 μg/kg 50 μg/kg 100 μg/kg倍硫磷 0.997 4 5 78.5(7.2) 104.1(6.4) 97.3(9.1) 0.994 1 5 76.4(6.3) 108.5(6.4) 99.3(3.2)丁苯吗啉 0.999 2 5 97.7(9.2) 92.5(8.4) 101.3(4.4) 0.995 1 5 97.5(2.2) 94.5(5.4) 101.3(6.1)毒死蜱 0.998 5 5 72.9(6.1) 103.3(8.5) 88.2(4.5) 0.994 6 5 78.4(2.1) 109.3(8.5) 88.2(4.5)4,4-二氯二苯甲酮 0.998 0 5 102.2(7.3) 96.3(7.1) 94.2(8.2) 0.998 9 5 106.2(7.3) 96.3(7.1) 94.2(8.2)吡咪唑 0.996 3 5 118.1(6.4) 105.5(9.1) 80.2(7.4) 0.998 3 5 114.1(6.4) 113.5(9.1) 80.2(7.4)对硫磷 0.997 8 5 94.9(9.2) 113.1(8.2) 99.3(6.4) 0.993 5 5 92.9(9.2) 115.4(8.2) 103.3(4.4)异氯磷 0.998 8 5 105.3(4.2) 121.3(9.2) 92.1(9.1) 0.998 4 5 102.3(4.2) 109.3(5.2) 95.1(6.1)氯酞酸甲酯 0.999 2 5 87.8(6.4) 97.9(6.8) 88.6(8.2) 0.995 2 5 89.8(4.8) 94.9(6.5) 87.6(6.2)氟噻草胺 0.996 7 10 94.4(6.7) 108.5(9.6) 102.4(8.2) 0.998 3 10 91.4(5.7) 107.5(9.3) 102.4(4.2)芬螨酯 0.997 8 5 89.6(7.5) 111.4(7.3) 100.5(5.2) 0.998 4 5 85.4(7.5) 108.4(2.3) 104.5(6.2)四氟醚唑 0.998 5 5 95.2(6.2) 114.3(5.6) 100.4(9.8) 0.996 5 5 97.4(5.2) 114.3(2.6) 83.4(4.8)氟咯草酮 0.995 9 5 95.7(7.8) 103.1(6.3) 99.3(9.1) 0.998 5 5 92.5(5.2) 113.1(7.3) 99.3(6.4)十二环吗啉 0.997 7 5 75.6(6.7) 86.5(6.2) 84.5(6.4) 0.993 1 5 71.6(6.7) 82.5(5.2) 88.5(5.4)增效胺 0.993 5 10 85.1(7.4) 78.5(7.2) 77.4(7.5) 0.998 4 10 79.1(3.4) 83.5(5.2) 74.4(6.3)仲丁灵 0.995 5 10 87.3(3.1) 85.4(6.2) 92.3(6.2) 0.998 5 10 86.5(3.1) 87.4(3.5) 92.3(5.4)双苯酰草胺 0.998 9 5 109.4(7.1) 81.6(3.6) 95.3(7.1) 0.997 8 5 103.4(4.1) 85.4(3.6) 98.7(3.1)异艾氏剂 0.994 5 5 106.2(6.2) 87.5(6.6) 89.7(7.5) 0.998 5 5 103.2(6.2) 84.5(6.4) 86.7(7.5)嘧啶磷 0.998 5 5 79.8(8.2) 89.4(7.1) 92.5(5.3) 0.999 5 5 81.4(6.2) 88.6(6.4) 94.5(3.8)异丙乐灵 0.999 4 10 105.6(8.1) 86.2(6.4) 97.5(4.6) 0.993 8 10 108.6(5.2) 88.2(6.2) 94.5(3.8)甲基异柳磷 0.999 5 20 — 97.4(6.1) 104.2(5.5) 0.998 4 20 — 93.5(6.4) 101.4(5.8)吡唑草胺 0.999 6 10 84.3(7.2) 96.3(8.4) 81.2(7.3) 0.998 9 5 85.9(6.5) 97.5(6.2) 88.2(5.3)二甲戊灵 0.998 7 10 95.6(6.2) 85.3(5.4) 98.3(5.1) 0.993 5 10 98.5(4.8) 87.5(3.8) 94.6(6.4)异戊乙净 0.999 4 5 106.3(9.5) 109.1(6.4) 91.6(6.3) 0.998 4 5 108.2(5.4) 108.1(4.8) 95.6(3.6)啶斑肟 0.998 8 10 78.9(6.2) 97.2(6.1) 101.4(5.2) 0.994 2 10 79.5(7.8) 99.5(4.5) 108.4(6.8)甲苯氟磺胺 0.998 8 10 82.9(9.6) 82.1(9.4) 82.5(8.2) 0.998 5 5 79.5(2.7) 81.6(9.4) 87.9(6.7)氟虫腈亚砜 0.993 8 5 104.5(9.2) 99.2(6.1) 80.5(9.3) 0.998 5 5 109.4(6.5) 98.7(3.5) 85.9(4.7)乙菌利 0.998 7 5 95.4(6.4) 98.4(8.2) 108.6(5.1) 0.994 4 5 103.4(5.8) 96.7(4.5) 112.6(6.8)地胺磷 0.999 8 20 — 97.6(6.2) 97.5(8.1) 0.998 2 20 — 92.6(6.2) 97.5(8.1)异柳磷 0.991 3 20 — 108.5(7.1) 96.7(7.2) 0.998 9 20 — 108.6(8.1) 93.5(8.6)喹硫磷 0.992 3 5 94.6(8.4) 96.4(6.2) 84.7(9.1) 0.998 5 5 96.4(5.2) 96.4(5.8) 85.4(7.2)三唑醇 0.994 6 20 — 102.5(9.1) 95.8(6.2) 0.990 4 20 — 106.5(7.4) 104.5(2.2)氟虫腈 0.998 4 5 79.9(9.2) 103.5(7.2) 96.6(5.4) 0.999 3 5 83.4(4.5) 107.3(3.2) 99.3(3.4)稻丰散 0.993 6 20 — 78.0(6.2) 82.1(7.1) 0.994 2 20 — 86.0(7.5) 84.1(6.1)氟丁酰草胺 0.993 1 10 73.8(6.1) 74.2(9.3) 79.1(9.5) 0.997 4 10 80.8(7.1) 75.2(3.5) 88.1(4.5)呋霜灵 0.997 4 5 74.2(8.2) 78.3(8.2) 79.7(4.3) 0.997 7 5 84.3(4.2) 90.3(7.2) 79.6(4.6)杀螨醚 0.992 0 5 78.2(7.2) 83.1(9.3) 88.4(6.1) 0.998 6 5 83.2(7.4) 95.1(6.3) 100.4(4.1)腐霉利 0.998 2 5 94.2(6.9) 92.1(4.2) 95.5(4.0) 0.991 2 5 99.2(6.5) 95.1(4.7) 93.5(6.0)整形醇 0.998 4 5 103.5(6.1) 104.1(4.0) 97.2(6.3) 0.997 4 5 108.2(4.1) 108.1(7.0) 95.2(4.3)杀扑磷 0.998 3 20 — 95.3(4.3) 88.5(7.4) 0.998 3 20 — 98.3(4.7) 84.5(6.4)双氯氰菌胺 0.998 2 5 102.3(3.2) 87.4(5.3) 103.4(6.2) 0.998 1 5 105.3(3.8) 83.4(5.6) 110.4(5.2)丙虫磷 0.992 5 5 94.8(9.2) 84.3(5.4) 94.3(6.2) 0.999 4 5 95.3(4.2) 94.3(7.4) 114.3(2.2)苯硫威 0.998 2 5 104.3(5.1) 89.4(4.2) 93.1(8.2) 0.998 5 5 109.3(5.3) 83.4(4.6) 103.1(4.2)氟吡甲禾灵 0.997 4 5 74.2(6.4) 87.2(7.4) 103.3(8.1) 0.998 7 5 94.4(6.5) 88.2(3.4) 104.2(5.1)嘧菌胺 0.998 2 5 101.4(6.1) 109.4(9.1) 86.3(5.5) 0.999 2 5 104.4(6.7) 105.4(4.1) 96.3(6.5)丁草胺 0.993 1 10 105.3(5.1) 76.5(8.1) 93.2(9.2) 0.993 6 10 104.3(4.1) 86.5(8.6) 96.2(3.2)灭菌磷 0.998 4 5 94.5(7.2) 110.2(8.1) 97.2(5.2) 0.998 5 5 97.5(7.6) 100.2(5.1) 95.2(3.2)粉唑醇 0.994 3 20 — 87.3(7.4) 105.1(7.1) 0.997 6 20 — 84.3(7.8) 107.1(5.1)敌草胺 0.994 5 5 103.3(5.2) 79.2(9.1) 102.1(5.2) 0.991 2 5 105.3(5.6) 82.2(5.1) 113.1(4.2)苯线磷 0.993 2 5 96.5(5.5) 83.4(9.2) 93.4(9.3) 0.992 3 5 96.1(8.5) 93.4(6.2) 94.4(9.4)己唑醇 0.995 4 5 105.3(7.4) 80.5(9.6) 109.2(7.3) 0.998 8 5 101.3(4.4) 82.5(5.6) 103.2(7.6)啶氧菌酯 0.993 0 10 106.4(7.4) 85.5(9.3) 104.1(7.2) 0.998 5 10 103.4(6.4) 96.5(4.3) 103.1(3.2)三环唑 0.993 1 5 95.1(4.3) 93.2(9.1) 94.5(6.4) 0.991 4 5 99.4(4.4) 103.7(7.3) 102.8(4.4)氟酰胺 0.994 2 5 89.1(8.2) 84.3(9.4) 102.5(9.6) 0.998 4 5 110.1(4.2) 93.3(9.5) 104.3(7.6)抑霉唑 0.998 5 5 92.4(6.5) 75.6(9.7) 84.8(6.9) 0.995 5 5 102.4(8.5) 115.6(4.7) 94.8(6.4)丙硫磷 0.998 8 20 — 107.2(9.3) 123.4(9.5) 0.998 5 20 — 107.2(9.3) 123.4(9.5)韭菜化合物苹果R2 检出限/(μg/kg)回收率/%(RSD/%) R2 检出限/(μg/kg)

续表3

回收率/%(RSD/%)10 μg/kg 50 μg/kg 100 μg/kg 10 μg/kg 50 μg/kg 100 μg/kg稻瘟灵 0.994 1 5 95.4(6.1) 80.2(9.4) 105.1(7.4) 0.998 5 5 97.3(5.4) 100.2(6.4) 108.4(3.4)丙溴磷 0.997 4 5 104.3(7.4) 113.5(9.6) 104.7(8.2) 0.994 5 5 112.3(6.4) 104.5(9.4) 99.7(3.2)烯效唑 0.992 9 20 — 85.8(9.2) 94.0(8.1) 0.990 5 20 — 103.8(7.2) 108.2(4.1)狄氏剂 0.998 5 5 113.5(8.4) 99.5(9.1) 105.2(4.3) 0.992 1 5 112.5(6.4) 109.5(9.4) 108.2(7.3)p,p’-滴滴伊 0.998 6 5 105.3(7.1) 81.2(9.5) 106.5(7.4) 0.998 4 5 103.3(3.1) 81.2(9.4) 103.9(6.4)丙草胺 0.992 5 10 92.5(6.6) 90.4(4.2) 94.5(5.3) 0.994 1 10 99.5(4.6) 100.4(6.2) 98.8(5.5)噁草酮 0.990 1 5 93.4(6.1) 94.2(4.5) 96.9(6.2) 0.993 5 5 94.4(6.1) 94.2(4.1) 96.3(4.2)腈菌唑 0.998 5 10 103.4(4.5) 75.6(9.7) 84.2(8.3) 0.998 3 5 112.4(4.6) 95.6(2.7) 104.2(3.3)苄氯三唑醇 0.998 3 5 104.2(7.3) 87.4(8.2) 101.4(5.3) 0.994 8 5 108.2(8.3) 84.4(8.2) 103.4(7.3)噻嗪酮 0.998 7 10 109.5(7.6) 92.7(4.8) 93.3(8.2) 0.998 4 5 112.5(7.8) 97.4(6.8) 98.2(4.2)氧环唑 0.999 2 5 97.5(9.5) 84.6(9.7) 108.8(9.3) 0.998 5 5 111.1(3.2) 96.5(9.4) 104.8(6.3)氟硅唑 0.998 5 5 101.1(4.3) 94.4(6.3) 95.5(4.2) 0.993 8 5 112.1(6.3) 95.3(8.4) 98.2(7.2)甲氧丙净 0.998 5 10 87.3(4.4) 84.5(8.1) 107.3(5.2) 0.998 7 5 101.3(4.6) 95.5(5.1) 103.2(5.9)氟虫腈砜 0.993 4 5 94.2(8.2) 97.1(4.4) 108.6 (8.3) 0.999 3 5 112.1(4.2) 108.3(7.4) 108.9(8.4)乙嘧酚磺酸酯 0.998 3 5 106.5(4.4) 83.5(5.3) 109.4(9.5) 0.998 9 5 104.5(4.7) 94.3(4.3) 107.4(6.5)醚菌酯 0.998 4 20 — 102.4(9.4) 95.3(6.4) 0.992 5 20 — 115.4(7.4) 103.3(5.4)除草醚 0.998 5 5 107.5(8.4) 96.5(7.1) 88.3(4.2) 0.998 2 5 104.5(8.6) 97.4(4.1) 84.3(6.2)异狄氏剂 0.998 3 10 96.3(7.4) 98.4(7.2) 95.4(6.3) 0.996 7 10 104.3(4.4) 112.2(6.2) 97.4(6.7)环丙唑醇 0.998 2 20 — 78.4(9.1) 92.2(7.3) 0.998 5 20 — 89.7(4.1) 102.3(5.3)环丙嘧啶醇 0.999 4 5 110.3(8.1) 97.2(9.4) 96.3(7.3) 0.998 0 5 114.2(6.1) 111.2(9.3) 106.3(8.3)乙滴滴 0.997 5 10 86.2(9.2) 72.8(9.2) 99.3(8.3) 0.998 5 10 96.4(5.4) 82.8(7.2) 105.3(4.3)虫螨腈 0.998 5 10 95.1(6.3) 90.4(9.5) 87.6(11.3) 0.998 3 5 105.3(7.3) 100.5(8.5) 97.4(10.2)乙酯杀螨醇 0.994 8 5 96.5(5.4) 80.3(4.3) 109.5(9.6) 0.999 5 5 103.5(4.2) 100.7(6.3) 102.4(5.5)倍硫磷亚砜 0.998 4 10 95.5(7.6) 92.3(8.5) 95.5(9.0) 0.991 4 5 104.5(7.6) 112.3(2.7) 105.6(2.9)酯菌胺 0.996 1 5 81.4(8.4) 93.5(8.6) 86.7(6.8) 0.994 4 5 94.4(8.8) 89.5(9.6) 106.4(7.8)乙环唑 0.998 2 5 95.1(6.3) 97.2(7.4) 96.5(8.6) 0.993 1 5 105.3(6.8) 103.2(6.4) 109.4(6.6)p,p’-滴滴滴 0.998 4 10 78.6(9.6) 78.4(6.3) 82.8(7.2) 0.998 6 10 88.5(9.8) 88.7(4.3) 92.6(5.3)麦草氟异丙酯 0.993 4 10 75.5(9.2) 73.4(8.9) 78.1(8.2) 0.998 7 5 85.2(7.2) 83.6(9.3) 98.6(6.2)倍硫磷砜 0.998 9 5 82.7(5.1) 89.3(6.2) 89.2(5.3) 0.997 5 5 92.6(5.5) 109.3(6.8) 99.4(6.3)o,p’-滴滴涕 0.993 6 10 88.2(8.4) 82.3(9.3) 93.2(6.1) 0.994 0 10 98.3(8.5) 102.3(7.3) 103.2(5.1)噁霜灵 0.998 5 10 92.5(5.6) 93.5(5.4) 95.3(4.5) 0.998 4 10 102.3(5.9) 104.9(4.4) 110.7(8.5)乙硫磷 0.998 9 20 — 105.2(4.4) 98.5(7.2) 0.998 2 20 — 106.2(7.3) 108.5(5.4)麦锈灵 0.998 8 5 95.3(6.1) 95.6(4.4) 88.5(7.2) 0.990 5 5 105.3(8.1) 107.6(4.5) 98.6(8.2)灭锈胺 0.993 6 5 102.3(8.4) 87.5(7.4) 103.1(8.3) 0.993 5 5 109.3(8.6) 97.4(7.6) 108.1(5.3)三唑磷 0.992 7 20 — 84.1(6.2) 93.2(7.3) 0.995 6 20 — 94.1(6.5) 103.2(8.3)呋酰胺 0.998 5 5 106.7(8.3) 106.1(6.4) 88.1(9.2) 0.993 1 5 105.6(5.3) 116.1(8.4) 108.1(9.6)三硫磷 0.994 5 5 104.5(7.1) 89.4(5.2) 93.5(8.3) 0.998 3 5 106.5(7.8) 99.4(8.2) 103.4(6.3)苯霜灵 0.995 5 10 108.2(6.3) 97.5(7.2) 103.5(8.4) 0.998 4 10 111.2(6.7) 107.3(6.2) 109.5(5.4)苯虫醚 0.998 6 5 101.3(6.2) 108.3(9.2) 86.9(5.3) 0.998 3 5 108.3(6.5) 101.3(8.2) 96.5(7.3)敌瘟磷 0.990 5 5 105.3(8.2) 86.8(9.1) 93.4(8.2) 0.994 3 5 115.3(4.2) 106.8(9.3) 103.8(5.2)喹氧灵 0.998 3 5 104.5(9.1) 112.6(8.2) 97.7(5.3) 0.996 2 5 96.5(9.5) 102.9(4.2) 98.6(7.3)苯腈磷 0.992 5 10 108.5(7.1) 87.4(7.3) 105.3(8.1) 0.998 4 10 106.5(3.8) 88.4(7.5) 95.3(7.1)硫丹硫酸酯 0.991 2 5 101.6(6.2) 89.1(9.1) 102.2(7.2) 0.993 2 5 105.4(8.2) 109.5(9.4) 108.2(5.2)氟草敏 0.995 1 5 96.5(5.2) 103.3(9.1) 93.1(7.2) 0.993 6 5 96.9(4.2) 93.8(9.5) 93.9(6.2)丙环唑 0.994 5 5 102.1(7.3) 90.2(8.7) 107.3(7.2) 0.995 5 5 106.8(7.8) 100.6(8.5) 99.3(6.2)p,p’-滴滴涕 0.993 3 20 — 91.4(9.2) 102.3(5.8) 0.998 3 10 103.5(7.2) 101.4(9.8) 92.3(6.8)戊唑醇 0.998 2 10 105.8(6.2) 109.4(10.2) 104.1(6.3) 0.994 8 10 95.8(6.9) 99.4(6.2) 94.1(4.3)氟苯嘧啶醇 0.997 3 5 74.3(9.1) 76.4(7.2) 84.3(5.2) 0.993 6 5 79.3(5.1) 86.4(7.7) 94.3(5.9)增效醚 0.998 7 10 102.2(8.1) 81.8(6.8) 96.2(7.0) 0.994 4 10 107.2(6.1) 91.8(6.6) 106.2(7.5)苯酰菌胺 0.994 5 20 — 84.2(5.2) 86.3(7.1) 0.998 8 20 — 94.2(8.2) 96.3(7.6)氟环唑 0.998 4 5 89.8(9.2) 88.4(5.1) 94.4(5.3) 0.995 5 5 99.8(7.2) 108.4(5.9) 104.4(8.3)拌种咯 0.998 5 5 104.1(5.1) 88.8(6.4) 94.5(4.6) 0.994 4 5 94.1(5.5) 98.8(7.4) 104.5(9.6)异狄氏剂酮 0.990 2 10 92.2(6.4) 93.1(6.7) 101.5(5.1) 0.998 5 5 98.2(6.8) 93.9(6.5) 108.5(7.1)糠菌唑 0.992 1 5 117.2(7.2) 109.1(8.3) 101.5(7.4) 0.993 4 5 103.2(7.5) 99.1(8.7) 111.5(5.4)溴螨酯 0.991 2 5 105.4(5.1) 107.6(3.3) 105.2(3.1) 0.993 2 5 102.4(5.9) 109.6(3.6) 101.2(4.1)韭菜化合物苹果R2 检出限/(μg/kg)回收率/%(RSD/%) R2 检出限/(μg/kg)

续表3

注:—.未检出。

韭菜回收率/%(RSD/%)10 μg/kg 50 μg/kg 100 μg/kg 10 μg/kg 50 μg/kg 100 μg/kg氟唑菌酰胺 0.998 7 5 103.1(6.1) 102.5(4.2) 91.7(4.3) 0.998 9 5 105.1(6.6) 102.9(4.8) 101.7(7.3)联苯肼酯 0.998 3 5 102.8(4.2) 103.4(5.1) 101.4(5.3) 0.998 7 5 108.8(4.8) 113.4(5.6) 111.4(6.3)联苯菊酯 0.998 2 10 119.5(9.4) 120.5(8.7) 112.5(8.1) 0.992 5 10 117.5(9.8) 116.5(3.7) 121.6 (6.1)甲氧滴滴涕 0.998 5 5 102.1(9.3) 105.5(6.2) 101.0(8.3) 0.993 5 5 107.1(7.3) 99.5(6.4) 91.0(6.3)乙螨唑 0.998 5 5 95.1(6.3) 98.4(7.2) 107.2(5.2) 0.997 7 5 99.1(6.3) 108.4(7.9) 103.2(7.2)吡螨胺 0.994 2 5 95.4(4.5) 102.3(6.5) 101.2(6.1) 0.998 0 5 101.4(4.5) 112.3(6.8) 99.2(6.7)三氯杀螨砜 0.993 1 5 107.3(8.3) 104.1(7.2) 96.5(7.3) 0.998 8 5 105.3(4.5) 107.1(6.2) 98.5(7.8)杀螺吗啉 0.993 5 20 — 95.7(6.1) 90.2(9.2) 0.998 9 20 — 85.3(7.1) 95.2(6.2)噁唑禾草灵 0.992 4 5 108.5(5.3) 106.2(5.1) 95.9(5.2) 0.991 3 5 104.6(7.3) 106.2(5.9) 105.4(7.2)哒螨灵 0.998 2 5 99.4(11.1) 103.1(7.3) 96.4(5.5) 0.996 8 5 93.4(11.7) 105.1(7.5) 106.4(7.5)喹禾灵 0.995 4 5 84.4(9.2) 79.5(9.3) 86.3(9.1) 0.993 7 5 83.4(6.2) 89.4(9.5) 96.3(6.1)氟氰戊菊酯 0.994 2 20 — 105.0(9.1) 106.2(8.3) 0.998 4 20 — 108.0(6.1) 110.2(5.3)氟硅菊酯 0.993 5 20 — 95.3(4.4) 104.5(6.6) 0.993 4 20 — 98.3(7.4) 105.5(2.6)氰戊菊酯 0.996 1 5 121.6(9.8) 118.1(8.4) 121.2(9.1) 0.998 4 5 119.7(8.8) 118.1(5.4) 120.2(9.3)丙炔氟草胺 0.995 3 5 111.3(7.7) 103.8(8.4) 92.1(9.3) 0.993 3 5 108.6(8.2) 103.4(8.3) 95.1(5.2)唑虫酰胺 0.994 3 5 97.3(8.1) 94.2(4.3) 103.4(8.5) 0.998 2 5 96.0(9.3) 94.2(9.4) 105.4(8.4)化合物苹果R2 检出限/(μg/kg)回收率/%(RSD/%) R2 检出限/(μg/kg)

图2 苹果样品中毒死蜱提取离子色谱对应的碎片离子响应值(aa)、毒死蜱标准物质谱图(b)和苹果样品中毒死蜱谱图(cc)
Fig. 2 Extracted ion chromatograms of chlorpyrifos in apple sample (a),mass spectrum of chlorpyrifos standards (b) and mass spectrum of chlorpyrifos in apple sample (c)

2.7 回溯性分析

GC-QTOF-MS常采集全谱,能够更全面地采集数据,数据采集与PCDL库中的化合物数目无关,因此采集完成可对数据进行回顾与重新分析,扩大目标范围。分析样品时把新的化合物戊菌唑保留时间、分子式、精确相对分子质量和CAS号等信息加入到234 种PCDL库中并采用实际样品进行验证,该化合物在各基质中线性大于0.990,在3 个添加水平(10、50、100 μg/kg)下的平均加标回收率为80.2%~120.4%,平均RSD为2.8%~10.1%,均满足检测相关要求。实际样品中3 例葡萄样品检出戊菌唑,检出量范围为0.052~0.15 mg/kg,未超过食品中农药最大残留限量。该方法可对目标化合物进行扩充和分析而不用重新采集实时数据,具有灵活性,便于农药残留高通量筛查和定量分析,是未来农产品风险监测技术的发展方向。

3 结 论

本实验建立了基于m-PFC柱净化,采用GC-QTOFMS快速测定果蔬中234 种农药残留的分析方法。m-PFC柱净化比传统QuEChERS前处理操作简便高效,能够有效降低复杂基质的干扰;GC-QTOF-MS通过保留时间、精确分子质量及定量离子与定性离子比率等信息进行定性分析,重复性好和准确度高,避免了假阳性和假阴性的出现。同时,GC-QTOF-MS采集全谱,可以对数据进行回顾和重新分析,扩展农药化合物筛查分析范围。该方法大大提高了检测的效率和检测的准确度,能够对农药多残留进行高通量快速筛查和定量,为果蔬中多种农药残留的风险监测提供了一种有力的技术手段。

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Rapid Screening of 234 Pesticide Residues in Vegetables and Fruits by Multi-plug Filtration Cleanup Method Combined with Gas Chromatography-Quadrupole Time of Flight Mass Spectrometry

MENG Zhijuan, HUANG Yunxia, DI Pengyue, ZHAO Limin, NIU Lisha, FAN Sufang*, LI Qiang*, ZHANG Yan
(Key Laboratory of Food Safety of Hebei Province, Hebei Food Inspection and Research Institute, Shijiazhuang 050091, China)

Abstract: A new method for screening pesticide residues in vegetables and fruits by multi-plug filtration cleanup (m-PFC)method combined with gas chromatography-quadrupole time of flight mass spectrometry (GC-QTOF-MS) was developed.The samples were extracted with acetonitrile, purified by m-PFC, and detected by GC-QTOF-MS. Qualitative analysis was carried out by retention time and accurate mass measurements in full scan mode and quantitation was performed using matrix-matched standard calibration, which could effectively eliminate matrix interference. Twelve typical samples (Chinese cabbage, celery, tomato, cucumber, spinach, Chinese leek, pakchoi, tangerine, pear, apple, grape, and orange) were used to evaluate the method. Good linearity was achieved for 234 pesticides in the concentration range of 5 to 500 μg/kg with correlation coef ficients greater than 0.990. The results showed that the limits of detection of this method were in the range of 5-20 μg/kg. The average recoveries at three spiked levels of 10, 50, and 100 μg/kg were in the range of 73.2%-124.8%, 75.5%-122.6% and 74.8%-121.7%, with relative standard deviations (RSDs) of 2.4%-13.2%, 2.8%-11.4% and 2.2%-10.5%, respectively. The method could effectively improve the detection ef ficiency of high-resolution mass spectrometry for high throughput screening of pesticide residues in vegetables and fruits, thereby having great potential for practical application.

Keywords: gas chromatography-quadrupole time of flight mass spectrometry; multi-plug filtration cleanup; pesticide residues; rapid screening; vegetables and fruits

收稿日期:2019-12-27

基金项目:“十三五”国家重点研发计划重点专项(2018YFC1603400);河北省科技计划项目(19225503D);国家市场监管总局技术保障专项(2019YJ009);河北省市场监督管理局科研计划项目(2020ZC06)

第一作者简介:孟志娟(1986—)(ORCID: 0000-0002-1664-1561),女,工程师,硕士,研究方向为食品质量与安全。E-mail: 912638213@qq.com

*通信作者简介:

范素芳(1985—)(ORCID: 0000-0002-5156-9251),女,高级工程师,博士,研究方向为食品质量与安全。E-mail: fansufang840502@sina.com

李强(1981—)(ORCID: 0000-0001-5744-1403),男,正高级工程师,硕士,研究方向为食品质量与安全。E-mail: liqiang@nepp.com.cn

DOI:10.7506/spkx1002-6630-20191227-328

中图分类号:O657.63

文献标志码:A

文章编号:1002-6630(2020)16-0272-14

引文格式:孟志娟, 黄云霞, 邸鹏月, 等. 快速滤过型净化法结合气相色谱-四极杆-飞行时间质谱同时筛查果蔬中234 种农药残留[J].食品科学, 2020, 41(16): 272-285. DOI:10.7506/spkx1002-6630-20191227-328. http://www.spkx.net.cn

MENG Zhijuan, HUANG Yunxia, DI Pengyue, et al. Rapid screening of 234 pesticide residues in vegetables and fruits by multi-plug filtration cleanup method combined with gas chromatography-quadrupole time of flight mass spectrometry[J].Food Science, 2020, 41(16): 272-285. (in Chinese with English abstract) DOI:10.7506/spkx1002-6630-20191227-328.http://www.spkx.net.cn