Chloromethane emissions in human breath.
Chloromethane emissions in human breath.
复制标题
DOI：
10.1016/j.scitotenv.2017.06.202
复制
发表时间：
2017-12
期刊：
影响因子：
--
通讯作者：
F. Keppler;J. Fischer;Tobias Sattler;D. Polag;Nicole Jaeger;H. Schöler;M. Greule
中科院分区：
文献类型：
--
作者：
F. Keppler;J. Fischer;Tobias Sattler;D. Polag;Nicole Jaeger;H. Schöler;M. Greule
氯甲烷（CH3Cl）是目前大气中含量最丰富的氯化有机化合物，约为万亿分之550（pptv），被认为是造成约16%的卤素催化平流层臭氧破坏的原因。虽然已知甲烷的排放来自牛等动物，但尚未报告甲烷的形成和人类的释放。在这项研究中，一个预浓缩单元加上气相色谱仪直接连接到质谱仪被用来精确地测量浓度的CH3Cl在呼出气中的pptv水平从31个人类受试者的年龄范围从3到87岁。我们提供的分析证据表明，所有受试者呼出的CH3Cl的范围为2.5至33十亿分之一的体积，水平显着超过吸入空气的一个因素高达60。如果这些排放量的平均值是世界人口的典型值，那么来自人类的大气CH3Cl的全球来源约为0.66 Gg yr− 1（0.33至1.48 Gg yr− 1），不到全球大气源强度的0.03%。在人体内观察到的氯化甲基的内源性形成可能会引起生物化学家和医学科学家的兴趣，因为CH3Cl也被认为是一种有效的甲基化剂，因此可能是未来医学研究诊断计划中的重要目标化合物。
Chloromethane (CH3Cl), currently the most abundant chlorinated organic compound in the atmosphere at around ~ 550 parts per trillion by volume (pptv), is considered responsible for approximately 16% of halogen-catalyzed stratospheric ozone destruction. Although emissions of CH3Cl are known to occur from animals such as cattle, formation and release of CH3Cl from humans has not yet been reported. In this study a pre-concentration unit coupled with a gas chromatograph directly linked to a mass spectrometer was used to precisely measure concentrations of CH3Cl at the pptv level in exhaled breath from 31 human subjects with ages ranging from 3 to 87 years. We provide analytical evidence that all subjects exhaled CH3Cl in the range of 2.5 to 33 parts per billion by volume, levels which significantly exceed those of inhaled air by a factor of up to 60. If the mean of these emissions was typical for the world's population, then the global source of atmospheric CH3Cl from humans would be around 0.66 Gg yr− 1(0.33 to 1.48 Gg yr− 1), which is less than 0.03% of the total annual global atmospheric source strength. The observed endogenous formation of a chlorinated methyl group in humans might be of interest to biochemists and medical scientists as CH3Cl is also known to be a potent methylating agent and thus, could be an important target compound in future medical research diagnostic programs.