ABSTRACT Inspired by a previous ‘Sauna, sweat and science’ study [Zech et al. Isot Environ Health Stud. 2015;51(3):439–447] and out of curiosity and enthusiasm for stable isotope and sauna research we aimed at answering the question ‘do we sweat (isotopically) what we drink’? We, therefore, pulse-labelled five test persons in a sauna experiment with beverages that were 2H-enriched at about +25,600 ‰. Sweat samples were collected during six sauna rounds and the hydrogen isotope composition δ2Hsweat was determined using an isotope ratio mass spectrometer. Before pulse labelling, δ2Hsweat – reflecting by approximation body water – ranged from –32 to –22 ‰. This is ∼35 ‰ enriched compared to usual mid-European drinking water and can be explained with hydrogen-bearing food as well as with the respiratory loss of 2H-depleted vapour. The absence of a clearly detectable 2H pulse in sweat after pulse labelling and δ2Hsweat results of ≤+250 ‰ due to a fast 2H equilibration with body water are moreover a clearly negative answer to our research question also in a short-term consideration. Given that the recovery of the tracer based on an isotope mass balance calculation is clearly below 100 %, we finally answer the question ‘where did the rest of the tracer go?’ GRAPHICAL ABSTRACT

中文翻译：

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桑拿、汗水和科学 II – 我们喝的东西会出汗吗？

摘要 受先前“桑拿、汗水和科学”研究的启发 [Zech 等人。Isot 环境健康梭哈。2015;51(3):439–447] 出于对稳定同位素和桑拿研究的好奇心和热情，我们旨在回答“我们喝什么会出汗（同位素）”这个问题？因此，我们在桑拿实验中对 5 名测试人员进行了脉冲标记，其中的 2H 浓度约为 +25,600 ‰。在六轮桑拿期间收集汗液样品，并使用同位素比质谱仪测定氢同位素组成 δ2Hsweat。在脉冲标记之前，δ2Hsweat – 由近似体水反射 – 范围从 –32 到 –22 ‰。与通常的中欧饮用水相比，这大约富含 35‰，可以用含氢食物以及 2H 耗尽蒸汽的呼吸损失来解释。脉冲标记后汗液中没有明显可检测的 2H 脉冲，并且由于 2H 与体内水分快速平衡，δ2Hsweat 结果≤+250 ‰，这也是对我们研究问题的短期考虑的明显否定答案。鉴于基于同位素质量平衡计算的示踪剂回收率明显低于 100%，我们最终回答了“其余示踪剂去哪儿了？”这个问题。图形概要 我们终于回答了“其余的示踪剂去了哪里？”这个问题。图形概要 我们终于回答了“其余的示踪剂去了哪里？”这个问题。图形概要