Human sweat can be collected non-invasively with low infectivity; however, its application as a determination method has been challenged due to the presence of trace amounts of chiral metabolites. Moreover, its application as a biological fluid for disease diagnosis has not been previously reported. In this study, the human dried sweat spot paper (DSSP) method was proposed for the derivatization of a novel mass spectrometric chiral probe, -[1-Oxo-5-(triphenylphosphonium) pentyl]-(S)-3-aminopyrrolidine (OTPA), determination and resolution of DL-lactic acid (DL-LA) enantiomers in human elbow sweat. The methodological validation revealed the resolution (Rs) as 1.78, the limit of detection (S/N = 3) as 20.83 fmol, good linearity (R ≥ 0.9996), and the intra-day and intra-day stability with RSD ranging from 0.53 to 10.85 %, while the average recovery rate of D-LA and L-LA were 104.00 % ± 4.68 % and 107.41 % ± 8.34 %, respectively, with high accuracy. In addition, the method was applied for the determination of DL-LA in the sweat on elbow of 10 healthy volunteers and 30 diabetic patients. The results demonstrated that the D/L ratio and L/D ratio were significantly different ( < 0.0001). In addition, a moderate positive linear correlation between the D/L-LA ratio in human sweat and fasting blood glucose level (r = 0.7744, < 0.0001) was observed, thereby suggesting that the D/L ratio of lactate in human sweat correlate the glucose level in human fasting blood. The D/L lactate ratio in human sweat could be used as a potential biomarker for diabetes screening. The method can be used to screen for diabetes by providing a dry sweat paper to test equipment and has the potential to be a non-invasive early-warning diagnostic tool for diabetes.

中文翻译：

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基于新型质谱探针标记的干汗点纸 (DSSP) 方法，用于检测和解析作为糖尿病潜在生物标志物的 DL-乳酸对映体


人体汗液可无创采集，传染性低；然而，由于存在微量手性代谢物，其作为测定方法的应用受到了挑战。此外，其作为生物液体用于疾病诊断的应用此前尚未见报道。在这项研究中，提出了人体干汗斑纸（DSSP）方法用于衍生化新型质谱手性探针，-[1-Oxo-5-(三苯基膦)戊基]-(S)-3-氨基吡咯烷(OTPA) ）、人肘汗液中DL-乳酸（DL-LA）对映体的测定和解析。方法学验证显示分离度（Rs）为1.78，检测限（S/N=3）为20.83fmol，线性良好（R≥0.9996），日内和日内稳定性RSD范围为0.53至10.85%，而D-LA和L-LA的平均回收率分别为104.00%±4.68%和107.41%±8.34%，准确度较高。此外，还应用该方法测定了10名健康志愿者和30名糖尿病患者肘部汗液中DL-LA的含量。结果表明，D/L 比和 L/D 比显着不同 (< 0.0001)。此外，观察到人体汗液中的 D/L-LA 比率与空腹血糖水平之间呈中度正线性相关（r = 0.7744，< 0.0001），从而表明人体汗液中乳酸的 D/L 比率与空腹血糖水平相关。人类空腹血液中的葡萄糖水平。人体汗液中的 D/L 乳酸比可作为糖尿病筛查的潜在生物标志物。该方法可通过提供干汗纸给测试设备来筛查糖尿病，并有潜力成为糖尿病的非侵入性早期预警诊断工具。