Shida Shizuka S, Nemoto Satoru, Matsuda Rieko
a Division of Foods , National Institute of Health Sciences , Tokyo , Japan.
J Environ Sci Health B. 2015;50(3):151-62. doi: 10.1080/03601234.2015.982381.
A sensitive and efficient method has been developed for the simultaneous determination of 73 multi-class acidic pesticides, such as phenoxy acid and sulfonylurea herbicides, in vegetables and fruits. The sample preparation procedure was carefully optimized for the efficient removal of co-extracted matrix components. The method involves extraction of acidic pesticides with acetonitrile containing hydrochloric acid, removal of water from crude extract by salting out, and sequential cleanup by octadecylsilyl silica gel and silica gel columns. For samples containing high amounts of pigments, such as spinach, additional cleanup using a graphitized carbon column was performed prior to liquid chromatography-mass spectrometry (LC-MS/MS) analysis. Recovery tests were performed for five times for each sample of cabbage, spinach, potato, eggplant, orange, and apple fortified at 0.01 mg kg-1. Out of the 73 tested pesticides, 70 for cabbage, 67 for spinach, 69 for potato, 67 for eggplant, 64 for orange, and 70 for apple were within the range of 70-120%, with relative standard deviations below 25%. Nitenpyram and pyrasulfotole showed low recoveries for all the samples tested, probably due to low recoveries from silica gel column. The developed method effectively removed co-extracted matrix components and was highly selective, with no interfering peaks found in the chromatograms of blank samples. The overall results indicate that the developed method is suitable for the quantitative analysis of acidic pesticide residues in vegetables and fruits.
已开发出一种灵敏且高效的方法，用于同时测定蔬菜和水果中的73种多类酸性农药，如苯氧羧酸类和磺酰脲类除草剂。仔细优化了样品制备程序，以有效去除共萃取的基质成分。该方法包括用含盐酸的乙腈萃取酸性农药，通过盐析从粗提物中除去水分，以及依次用十八烷基硅烷硅胶柱和硅胶柱进行净化。对于含有大量色素的样品，如菠菜，在液相色谱 - 质谱联用（LC-MS/MS）分析之前，使用石墨化碳柱进行额外净化。对在0.01 mg kg-1水平下加标的卷心菜、菠菜、土豆、茄子、橙子和苹果的每个样品进行了五次回收率测试。在所测试的73种农药中，卷心菜的70种、菠菜的67种、土豆的69种、茄子的67种、橙子的64种和苹果的70种回收率在70 - 120%范围内，相对标准偏差低于25%。烯啶虫胺和吡蚜呋酮在所测试的所有样品中回收率较低，可能是由于从硅胶柱中的回收率较低。所开发的方法有效去除了共萃取的基质成分，具有高度选择性，空白样品色谱图中未发现干扰峰。总体结果表明，所开发的方法适用于蔬菜和水果中酸性农药残留的定量分析。
