Department of Environmental and Occupational Health, College of Medicine, National Cheng Kung University, 138 Sheng-Li Road, Tainan 704, Taiwan.
Instrumentation Center, National Taiwan University, No. 1, Sec. 4, Roosevelt Rd. Taipei 106, Taiwan.
Anal Chim Acta. 2019 Apr 4;1052:84-95. doi: 10.1016/j.aca.2018.11.009. Epub 2018 Nov 13.
Urine and hair are used for assessing human exposure to toxicants. Urine tests can show acute toxicant exposure. Hair analysis can be used to determine chronic toxicant exposure after months to years; however, compared to urine, hair analysis in exposure assessments is much less frequently investigated. Urine and hair are different matrices, and their mechanisms of toxicant metabolite incorporation are different. The toxicant metabolites present in urine and hair may also be different. To clarify this issue, a procedure was developed to identify toxicant metabolites in rat samples using a mass spectrometry-based metabolomic data processing method. Di-(2-propylheptyl) phthalate (DPHP), an industrial plasticizer, was used as the model toxicant. The developed procedure identified not only known DPHP metabolites (mono-(propyl-6-oxo-heptyl) phthalate, mono-(propyl-6-hydroxyheptyl) phthalate, and mono-(propyl-6-carboxyhexyl) phthalate) but also novel metabolites that were structurally related to DPHP in the rat samples, indicating that the developed procedure successfully identified toxicant metabolites in in vivo samples. Among the 62 tentative metabolites identified from the 7-day urine and the 28-day hair samples, 33 were detected in only the urine samples, 19 were detected in only the hair samples, and 10 were identified in both the urine and hair samples. A total of 15 out of the 62 metabolites were confirmed as DPHP structure-related metabolites based on MS/MS analysis. Among the 15 DPHP structure-related metabolites, only 2 metabolites were present in both the urine and hair samples. These results suggested that the metabolites identified in urine could not be applied to exposure assessments based on hair analysis.
尿液和头发可用于评估人体暴露于有毒物质的情况。尿液检测可显示急性有毒物质暴露。毛发分析可用于确定数月至数年后的慢性有毒物质暴露情况；然而，与尿液相比，毛发分析在暴露评估中的研究要少得多。尿液和头发是不同的基质，其有毒物质代谢物的掺入机制也不同。尿液和头发中存在的有毒物质代谢物也可能不同。为了阐明这个问题，开发了一种使用基于质谱的代谢组学数据处理方法来鉴定大鼠样本中毒物代谢物的程序。邻苯二甲酸二（2-丙基庚基）酯（DPHP），一种工业增塑剂，被用作模型有毒物质。所开发的程序不仅鉴定了已知的 DPHP 代谢物（单-（丙基-6-氧庚基）邻苯二甲酸酯、单-（丙基-6-羟基庚基）邻苯二甲酸酯和单-（丙基-6-羧基己基）邻苯二甲酸酯），还鉴定了大鼠样本中与 DPHP 结构相关的新型代谢物，表明该程序成功地鉴定了体内样本中的有毒物质代谢物。在 7 天尿液和 28 天头发样本中鉴定出的 62 种暂定代谢物中，33 种仅在尿液样本中检测到，19 种仅在头发样本中检测到，10 种在尿液和头发样本中均检测到。基于 MS/MS 分析，从 62 种代谢物中总共确认了 15 种 DPHP 结构相关代谢物。在这 15 种 DPHP 结构相关代谢物中，只有 2 种代谢物同时存在于尿液和头发样本中。这些结果表明，尿液中鉴定出的代谢物不能应用于基于毛发分析的暴露评估。
