Yamada Nobuyuki, Takahata Jutaro, Sasaki Kumiko, Toyoda Masatake, Nakamura Ryuji, Yoshida Kikuyoshi
Sendai City Institute of Public Health: 2-5-10, Oroshi-machi-higashi, Wakabayashi-ku, Sendai-shi 984-0002, Japan.
Shokuhin Eiseigaku Zasshi. 2002 Aug;43(4):196-201. doi: 10.3358/shokueishi.43.196.
We studied a gas chromatographic method for the determination of dichlorvos (DDVP) and trichlorfon (DEP) in agricultural products. DDVP and DEP were extracted from agricultural products with acetone and re-extracted with ethyl acetate instead of dichloromethane. DDVP and DEP were eluted in one fraction on a silica gel column using n-hexane-acetone (1:1). DEP is a thermally labile compound, so it was derived to a more thermally stable compound by acylation with N-methylbis(trifluoroacetamide) and pyridine in acetone at 60 degrees C for 2 hours. DDVP and the DEP-TFA derivative were determined simultaneously by GC-FPD. The recoveries of DDVP and DEP from agricultural products spiked at levels of 0.1 microgram/g were 72.6-117.7% and 86.2-106.6%, respectively. The detection limits were 0.03 microgram/g in powdered tea and < or = 0.01 microgram/g in other samples. An interlaboratory study by 6 laboratories was conducted to validate this proposed method for 6 crops. Repeatability ranged from 3.1 to 7.8% for DDVP and from 3.4 to 8.3% for DEP, and reproducibility, from 6.9 to 15.5% for DDVP, and from 7.9 to 21.8% for DEP. Precision values were well within statistically predicted levels.
我们研究了一种气相色谱法，用于测定农产品中的敌敌畏（DDVP）和敌百虫（DEP）。用丙酮从农产品中提取DDVP和DEP，并用乙酸乙酯而非二氯甲烷进行再提取。在硅胶柱上，使用正己烷 - 丙酮（1:1）将DDVP和DEP一次性洗脱。DEP是一种热不稳定化合物，因此在60℃下于丙酮中用N - 甲基双（三氟乙酰胺）和吡啶酰化2小时，将其转化为更热稳定的化合物。通过气相色谱 - 火焰光度检测器（GC - FPD）同时测定DDVP和DEP - TFA衍生物。在添加水平为0.1微克/克的农产品中，DDVP和DEP的回收率分别为72.6 - 117.7%和86.2 - 106.6%。在茶叶粉中的检测限为0.03微克/克，在其他样品中≤0.01微克/克。由6个实验室进行了一项实验室间研究，以验证该方法对6种作物的适用性。DDVP的重复性范围为3.1%至7.8%，DEP的重复性范围为3.4%至8.3%；DDVP的再现性范围为6.9%至15.5%，DEP的再现性范围为7.9%至21.8%。精密度值完全在统计预测水平之内。
