ISTerre, Université Grenoble Alpes, CNRS, CS 40700, 38058 Grenoble, France.
Laboratoire Chrono Environnement, Université de Franche-Comté, CNRS , 25030 Besançon, France.
Environ Sci Technol. 2016 Oct 4;50(19):10721-10729. doi: 10.1021/acs.est.6b03468. Epub 2016 Sep 22.
Humans are contaminated by mercury in different forms from different sources. In practice, contamination by methylmercury from fish consumption is assessed by measuring hair mercury concentration, whereas exposure to elemental and inorganic mercury from other sources is tested by analysis of blood or urine. Here, we show that diverse sources of hair mercury at concentrations as low as 0.5 ppm can be individually identified by specific coordination to C, N, and S ligands with high energy-resolution X-ray absorption spectroscopy. Methylmercury from seafood, ethylmercury used as a bactericide, inorganic mercury from dental amalgams, and exogenously derived atmospheric mercury bind in distinctive intermolecular configurations to hair proteins, as supported by molecular modeling. A mercury spike located by X-ray nanofluorescence on one hair strand could even be dated to removal of a single dental amalgam. Chemical forms of other known or putative toxic metals in human tissues could be identified by this approach with potential broader applications to forensic, energy, and materials science.
人类通过不同的来源以不同的形式接触汞。在实践中，通过测量头发中的汞浓度来评估因食用鱼类而导致的甲基汞污染，而通过分析血液或尿液来检测来自其他来源的元素汞和无机汞。在这里，我们通过高能量分辨率 X 射线吸收光谱表明，浓度低至 0.5ppm 的不同来源的头发汞可以通过与 C、N 和 S 配体的特定配位来单独识别。海鲜中的甲基汞、用作杀菌剂的乙基汞、来自牙科汞合金的无机汞和外源性大气汞以独特的分子间构型与头发蛋白结合，这得到了分子建模的支持。通过 X 射线纳米荧光在一根头发丝上定位的汞峰值甚至可以追溯到单个牙科汞合金的去除。通过这种方法可以识别人体组织中其他已知或推测的有毒金属的化学形态，可能具有更广泛的法医、能源和材料科学应用。
