Mercadante R, Polledri E, Scurati S, Moretto A, Fustinoni S
Department of Clinical Sciences and Community Health, Università degli Studi di Milano and Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico , Milan, Italy.
Chem Res Toxicol. 2014 Nov 17;27(11):1943-9. doi: 10.1021/tx500291t. Epub 2014 Oct 10.
Tebuconazole (TEB) is a fungicide used in agriculture; the objective of this work was to identify and quantify TEB metabolites in human urine. Samples from seven vineyard workers exposed to TEB were submitted to liquid chromatography interfaced with a triple quadrupole mass spectrometer, equipped with an electron spray source, and a linear ion trap to gain a profile of candidate metabolites. Based on the presence of the ion m/z 70 in the MS/MS spectra, which corresponds to protonated triazole (a specific moiety of TEB), and the isotopic pattern of the molecular ions, typical of molecules with one chlorine atom, hydroxyl and carboxyl derivatives of TEB, that is, TEB-OH and TEB-COOH, were identified as major metabolites, both as free molecules and as glucuronide (Glc) conjugates. The mean molar fractions were 0.67, 0.13, 0.13, and 0.07 for TEB-O-Glc, TEB-OH, TEB-COO-Glc, and TEB-COOH. Urine samples were submitted to hydrolysis with β-glucuronidase, and the free compounds were quantified in the presence of deuterated TEB (TEB-d6) as the internal standard (IS), by multiple reaction monitoring (MRM) mode. The assay was linear in the ranges of 0.2-600 μg/L and 0.1-240 μg/L for TEB-OH and TEB-COOH, respectively; precision, accuracy, and the limit of quantification (LOQ) were <3.1%, 98-103%, and 0.3 μg/L for both analytes. An evaluation of matrix effects showed that the use of TEB-d6 controlled these sources of bias. The urinary levels of TEB-OH and TEB-COOH in specimens collected from farmers exposed to TEB ranged from 10 to 473 and from 3 to 159 μg/L, respectively.
戊唑醇（TEB）是一种农业用杀菌剂；本研究的目的是鉴定和定量人尿液中的TEB代谢物。采集了7名接触TEB的葡萄园工人的样本，将其提交给与配备电子喷雾源的三重四极杆质谱仪和线性离子阱联用的液相色谱仪，以获取候选代谢物的图谱。基于MS/MS谱图中m/z 70离子的存在（其对应于质子化三唑，TEB的一个特定部分）以及分子离子的同位素模式（这是具有一个氯原子的分子的典型特征），鉴定出TEB的羟基和羧基衍生物，即TEB-OH和TEB-COOH为主要代谢物，它们既以游离分子形式存在，也以葡糖醛酸（Glc）共轭物形式存在。TEB-O-Glc、TEB-OH、TEB-COO-Glc和TEB-COOH的平均摩尔分数分别为0.67、0.13、0.13和0.07。尿液样本用β-葡糖醛酸酶进行水解，并以氘代TEB（TEB-d6）作为内标（IS），通过多反应监测（MRM）模式对游离化合物进行定量。TEB-OH和TEB-COOH的测定在0.2 - 600 μg/L和0.1 - 240 μg/L范围内分别呈线性；两种分析物的精密度、准确度和定量限（LOQ）分别<3.1%、98 - 103%和0.3 μg/L。基质效应评估表明，使用TEB-d6可控制这些偏差来源。从接触TEB的农民采集的样本中，TEB-OH和TEB-COOH的尿液水平分别为10至473 μg/L和3至159 μg/L。
