Department of Analytical Chemistry, Faculty of Chemistry, University of Valencia, València, Spain.
J Chromatogr A. 2011 May 20;1218(20):3013-21. doi: 10.1016/j.chroma.2011.03.045. Epub 2011 Mar 26.
The in vivo metabolism of the xenobiotic agent 2-ethylhexyl 4-(N,N-dimethylamino)benzoate (EDP), a UV filter commonly used in sunscreen cosmetic products, was studied by targeting metabolomics analysis in human urine. The metabolomic study involved the use of urine from male and female volunteers before and after application of an EDP-containing sunscreen cosmetic. The metabolism of EDP in urine was studied by using the triple quadrupole detector in a combination of Precursor Ion Scanning and Neutral Loss Scanning modes, with and without enzymatic hydrolysis. Detected metabolites were subsequently confirmed as glucuronide conjugates of 4-(N,N-dimethylamino)benzoic acid and 4-(N-methylamino)benzoic acid by liquid chromatography-time-of-flight/mass spectrometry (LC-TOF/MS) in the accurate mass mode. In this way, the existence of phase II metabolism in the detoxification of EDP by effects of the lipophilic character of this sunscreen agent was confirmed. Hence, to study the in vivo metabolism of EDP, a fully automated method using a solid-phase extraction (SPE) workstation connected on-line to a liquid chromatograph and a triple quadrupole mass analyzer (LC-MS/MS) was developed. The ensuing hyphenated method is very simple and requires minimal human intervention. Following thorough optimization of the SPE and LC-MS/MS conditions, the analytical procedure was validated and standard addition calibration used for the quantitative correction of matrix effects. The proposed method was applied to determine the phase I metabolites of EDP in urine samples and afforded limits of detection from 0.1 to 1.1 ng and accuracy of 91-107% with relative standard deviations in the range 1.5-8.7% (sample volume: 100 μL). Based on the results of in vivo percutaneous absorption of a single application of the sunscreen, about 0.5% of the amount of the applied EDP is excreted in urine.
本研究采用靶向代谢组学分析方法，研究了一种在防晒霜等化妆品中常用的外源性物质 2-乙基己基 4-（N,N-二甲基氨基）苯甲酸酯（EDP）在人体尿液中的代谢情况。代谢组学研究涉及使用男性和女性志愿者在使用含 EDP 的防晒霜前后的尿液。使用三重四极杆检测器，结合前体离子扫描和中性丢失扫描模式，以及有无酶水解，对 EDP 在尿液中的代谢产物进行了研究。随后，通过液相色谱-飞行时间/质谱（LC-TOF/MS）在精确质量模式下对检测到的代谢产物进行了确证，确证其为 4-（N,N-二甲基氨基）苯甲酸和 4-（N-甲基氨基）苯甲酸的葡萄糖醛酸缀合物。由此证实，由于该防晒霜的亲脂性，EDP 通过 II 相代谢解毒。因此，为了研究 EDP 的体内代谢情况，开发了一种使用固相萃取（SPE）工作站与液相色谱和三重四极杆质谱（LC-MS/MS）在线连接的全自动方法。该联用方法非常简单，需要的人工干预最少。在对 SPE 和 LC-MS/MS 条件进行了彻底优化后，对分析程序进行了验证，并采用标准加入校准法对基质效应进行了定量校正。该方法应用于测定尿液中 EDP 的 I 相代谢产物，检出限为 0.1-1.1ng，准确度为 91%-107%，相对标准偏差为 1.5%-8.7%（样品体积：100μL）。基于单次应用防晒霜经皮吸收的体内研究结果，约有 0.5%的应用 EDP 以尿液形式排泄。
