为了评估非职业接触的普通人群对环境中苯系物的暴露量，有必要对其尿液中苯系物代谢产物（MOBCs）的浓度进行测定。然而现有的测定方法普遍存在目标分析物种类少、基质效应高、检测灵敏度低、同位素内标获取困难等问题。为了解决上述问题，本项目拟将花粉固相萃取和稳定同位素标记技术引入MOBCs分析中。首先利用花粉表面富含多种官能团的性质,将其作为SPE吸附剂，通过氢键、亲水以及π-π相互作用选择性的分离和纯化尿样中的MOBCs；接着采用N,N-二甲基乙二胺（DMED）和 d4-DMED对目标MOBCs进行衍生，从而将质谱易电离的叔胺基团和轻/重同位素标签引入MOBCs，以提高检测灵敏度和准确度；最后结合高效液相色谱串联质谱分析，建立尿样中多种MOBCs高灵敏的同时测定的新方法。本项目的实施可为苯系物环境暴露生物监测以及科学制定综合的苯系物生物限值标准提供技术支撑。

To assess the exposure of non-occupational population to benzene series, it is necessary for monitoring the metabolites of benzene series (MOBCs) in their urine. However, some disadvantages in previous reports for the analysis of MOBCs were existed, such as few target analytes, high matrix effect, low detection sensitivity and difficulty of obtaining isotope internal standards. To solve the above problems, the current project intends to introduce pollen solid phase extraction and stable isotope labeling technology into MOBCs analysis. First, we employ pollen as SPE adsorbent due to its characteristics of multiple functional groups on the surface, which can selectively separate and purify MOBCs from urine by hydrogen bond, hydrophilic and π-π interaction. Then, the target MOBCs are derivatized by N,N-dimethyl ethylenediamine, (DMED) and d4-DMED, so that the easily ionized tertiary amine group and light/heavy isotope label are introduced into MOBCs to improve detection sensitivity and accuracy in electrospray ionization mass spectrometry analysis. Finally, combined with HPLC-MS/MS analysis, we will develop a new and high sensitive method for the simultaneous determination of various MOBCs in urine. The implementation of this project will provide technical support not only for assessing the exposure of non-occupational population to benzene series in the environment, but also for the scientific development of the comprehensive biological limit value of benzene series.