Department of Occupational Health, School of Public Health, Hamadan University of Medical Sciences, PO Box 65175-4171, Hamadan, 6517838695, Iran.
Department of Analytical Chemistry, Bu-Ali Sina University, Hamadan, Iran.
Arch Toxicol. 2018 Jan;92(1):213-222. doi: 10.1007/s00204-017-2057-z. Epub 2017 Sep 4.
Mandelic acid (MA) is a major metabolite of ethylbenzene and styrene. For the first time, a selective, fast, and easy-to-use procedure was developed for the determination of MA in urine samples. The new procedure is based on MIMEPS, the combination of a molecularly imprinted polymer (MIP) and microextraction by packed sorbent (MEPS). High-performance liquid chromatography with ultraviolet detection (HPLC-UV) was used for the separation and determination of MA. The bulk polymerization method was used to synthesize the MIP, and the MIP and non-imprinted polymer (NIP) were characterized by Fourier transform infrared spectroscopy. The selectivity of the MIP was investigated in the presence of interferents. In addition, we investigated the various parameters that affect the performance of the MEPS, including the pH of the sample, the number of extraction cycles, sample volume, and the types and volumes of the washing and elution solvents. A six-point calibration curve was obtained in the range of 0.2-20 µg/mL (R = 0.9994). The extraction recovery was more than 88.8%. The limit of detection and the limit of quantitation were 0.06 and 0.2 µg/mL, respectively. The intra- and inter-day precisions were in the range of 3.6-4.7% and 3.8-5.1%, respectively. The accuracy was -8.4 to -11.1%. The optimized procedure was selective, sensitive, and rapid, and it was both user friendly and environmentally friendly. The sample preparation process took only about 5 min, so the MIMEPS-HPLC-UV procedure is recommended as an alternative for the biomonitoring of workers exposed to ethylbenzene and/or styrene.
扁桃酸（MA）是乙苯和苯乙烯的主要代谢物。本文首次建立了一种选择性强、快速、简便的尿液样品中 MA 测定方法。新方法基于分子印迹聚合物（MIP）和填充固相微萃取（MEPS）的组合（MIMEPS）。采用高效液相色谱-紫外检测（HPLC-UV）对 MA 进行分离和测定。采用本体聚合方法合成 MIP，并用傅里叶变换红外光谱对 MIP 和非印迹聚合物（NIP）进行了表征。考察了在存在干扰物的情况下 MIP 的选择性。此外，还考察了影响 MEPS 性能的各种参数，包括样品的 pH 值、萃取循环次数、样品体积以及洗涤和洗脱溶剂的种类和体积。在 0.2-20 µg/mL 范围内得到了六点校准曲线（R = 0.9994）。萃取回收率大于 88.8%。检测限和定量限分别为 0.06 和 0.2 µg/mL。日内和日间精密度分别在 3.6-4.7%和 3.8-5.1%范围内。准确度为-8.4 至-11.1%。优化后的方法具有选择性、灵敏性和快速性，操作简便，对环境友好。样品制备过程仅需约 5 min，因此推荐 MIMEPS-HPLC-UV 方法作为乙苯和/或苯乙烯接触工人生物监测的替代方法。
