食品科学

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固定时间-离子选择性电极浓度直读法快速测定腐竹中的硼砂

高向阳,魏姜勉,张 娜   

  1. 1.郑州科技学院食品科学与工程学院,河南 郑州 450064;2.河南农业大学食品科学技术学院,河南 郑州 450002
  • 出版日期:2013-09-25 发布日期:2013-09-27

Rapid Determination of Borax in Yuba by Fixed-Time Direct-Reading Ion Selective Electrode Method

GAO Xiang-yang,WEI Jiang-mian,ZHANG Na   

  1. 1. School of Food Science and Engineering, University for Science and Technology Zhengzhou, Zhengzhou 450064, China;
    2. College of Food Science and Technology, Henan Agricultural University, Zhengzhou 450002, China
  • Online:2013-09-25 Published:2013-09-27

摘要:

为建立一种快速测定食品中硼砂的新方法,以腐竹为样品,经酸化、氟化,使硼砂转化为氟硼酸根,用氟硼酸根离子选择性电极固定时间浓度直读法测定。结果表明:酸化和氟化过程分别需1mol/L硫酸1.00mL,4mol/L氢氟酸4.00mL,当氟化温度80℃、氟化时间5min时,样品测定的相对标准偏差为0.076%(n=11)、加标回收率为93.04%~104.2%、氟硼酸根离子的最低检出限为1.12×10-5mol/L。该法成本低廉、无需作图、简便迅速,利于样品的现场快速分析,结果满意。

关键词: 离子选择性电极, 浓度直读, 硼砂, 腐竹, 固定时间法, 快速测定

Abstract:

A fixed-time direct-reading ion selective electrode method was proposed for the rapid determination of borax
in yuba. Samples were acidified and fluorinated to form fluoroborate ion, which were measured by the method. Upon
acdification with 1.00 mL of 1 mol/L sulfuric acid and fluorination at 80 ℃ for 5 min with 4.00 mL of 4 mol/L hydrofluoric
acid, avrage recovery rates for spiked samples ranged from 93.04% to 104.2%, with RSD of 0.076% (n = 11). The detection
limit for fluoroborate ion was 1.12 × 10-5 mol/L. The method is cheap, simple, quick, calibration-curve-free and useful for
on-site determination with satisfying results.

Key words: ion-selective electrode (ISE), direct concentration reading, borax, yuba, fixed time method, rapid determination