Improved cleanup and determination of dialkyl phosphates in the urine of children exposed to organophosphorus insecticides
Improved cleanup and determination of dialkyl phosphates in the urine of children exposed to organophosphorus insecticides
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DOI：
10.1093/jat/23.4.230
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发表时间：
1999-07-01
影响因子：
2.5
通讯作者：
Kalman, DA
中科院分区：
文献类型：
--
作者：
Moate, TF;Lu, C;Kalman, DA
有机磷杀虫剂的二烷基磷酸盐尿代谢物的分析已被用于估计非职业暴露人群（包括儿童）的剂量。必须继续改进分析方法，以便准确和可重复地测量小于10 ng/mL的这些代谢物。二烷基磷酸酯通常通过气相色谱法（GC）和火焰光度检测器以其五氟苄基溴衍生物的形式测定。本文介绍了一种改进的尿液预净化方法，采用固相萃取、衍生化和气相色谱分析。该方法包括定量测定以下磷酸二烷基酯代谢物：磷酸二甲酯、磷酸二乙酯、硫代磷酸二甲酯、硫代磷酸二乙酯和二硫代磷酸二甲酯。尿液样品的额外净化允许增加样品量并提高灵敏度，同时最大限度地减少与衍生化相关的干扰和变异性。样品等分试样量为5 mL，磷酸二甲酯和磷酸二乙酯的定量限为10 ng/mL尿液，硫代磷酸二甲酯、硫代磷酸二乙酯和二硫代磷酸二甲酯的定量限为2 ng/mL尿液。该方法灵敏度水平允许在非职业暴露人群中约75%的个体中定量测定痕量磷酸二烷基酯。这种简化的方法增加了样品通量，提供了用于分析的干净提取物，并且不需要定制的玻璃器皿。
Analysis of dialkylphosphate urinary metabolites of organophosphorus insecticides has been used to estimate dose in nonoccupationally exposed populations, including children. Analytical methods must continue to be improved in order to accurately and reproducibly measure less than 10 ng/mL of these metabolites. Dialkyl phosphates are commonly determined as their pentafluorobenzyl bromide derivatives via gas chromatography (GC) with flame photometric detection. Presented here is an improved method for precleanup of urine using solid-phase extraction, followed by derivatization and GC analysis. The method includes the quantitative determination of the following dialkyl phosphate metabolites: dimethylphosphate, diethylphosphate, dimethylthiophosphate, diethylthiophosphate, and dimethyldithiophosphate. Additional cleanup of urine samples allows for increasing sample size and improving sensitivity while minimizing interferences and variability associated with derivatization. Sample aliquot size was 5 mL with limits of quantitation of 10 ng/mL of urine for dimethylphosphate and diethylphosphate and 2 ng/mL of urine for dimethylthiophosphate, diethylthiophosphate, and dimethyldithiophosphate. This level of method sensitivity allows for quantitative determination of trace dialkyl phosphates in approximately 75% of individuals in nonoccupationally exposed populations. This streamlined method increases sample throughput, provides a clean extract for analysis, and requires no custom glassware.