Qualitative- and quantitative analysis of the metabolome of sweat sampled from the fingertips

Max Lennart Feuerstein
2018 unpublished
Within the scope of this work, an untargeted metabolomics method for the investigation of blood and sweat sampled from the fingerprints was developed using an UPLC-MS (Ultra Performance Liquid Chro-matography- mass spectrometry) platform. An internal compound database containing 95 small molecules was developed by tandem mass spectrometric (MS2) analysis of diluted coffee, extracted choc-olate, as well as sweat samples and blood extracts obtained from seven individuals, before- and after the
more » ... sumption of coffee or chocolate. During two intervention studies the pharmacokinetic profiles of the most abundant xenobiotics present in coffee and chocolate, as well as the primary- and secondary metabolites of caffeine (CF), were investigated in sweat and blood. Based on the kinetic data, the distinction of coffee and chocolate consumption was possible using CF-, theobromine (TB)- and paraxanthine (PX) levels in sweat as marker substances. The chromatographic method was optimized and a method for the quantitation of CF and its primary metabolites in sweat was established and validated. During a field study the developed method was used to control the compliance of volunteers participating in a double-blind study at the Centre of Chronobiology of the Psychiatric Hospital of the University of Basel (UPK Basel). Every volunteer took part in three phases of the study either ingesting CF or a placebo or underwent a withdrawal phase. Phases were composed of two ambulatory parts separated by a stationary part. Sampling devices were prepared at the Department of Analytical Chemistry of the University of Vienna and were sent to the UPK Basel prior to sampling, where sampling itself was carried out by our partners during the stationary part of the study, while subjects sampled themselves during the ambulatory part. Sweat samples were sent back to Vienna, where CF and its metabolites were extracted and quantified. Based on the CF-, TB- and PX content in sweat, we were able to successfully correlate sets of samples to the correspon [...]
doi:10.25365/thesis.52442 fatcat:biklfa3gqzba3m4of73gsy5gga