Risk of unintentional antidoping rule violations by consumption of hemp products.

Consumption of hemp products is continuously growing, with an expanding scope of applications. Suppliers operate through different distribution channels, but the Internet is a major retail platform. Hemp products are prepared from cannabis plants and, therefore, might contain a variety of different natural cannabinoids. According to the regulations of the World Anti-Doping Agency, all natural and synthetic cannabinoids are prohibited in-competition, with the explicit exemption of cannabidiol. Therefore, an investigation of 23 hemp products for the presence of cannabinoids was performed to determine the likelihood of unintentional violations of anti-doping regulations. An assay for the detection of 16 cannabinoids in nutritional supplements was developed and validated. The sample preparation consisted of QuEChERS extraction, trimethylsilylation, and analysis by gas chromatography/tandem mass spectrometry. All 23 commercially available hemp products were analyzed, and assay characteristics such as selectivity, limit of detection, limit of identification, limit of quantification, linearity, imprecision, recovery, and accuracy were determined. Twenty of 23 hemp products included a variety of cannabinoids at, occasionally, substantial concentrations, with four products covering the entire spectrum of tested cannabinoids. An ethics committee-approved single-dose administration study was conducted with the commercially available hemp products, investigating the presence of 16 cannabinoids in urine collected pre- and post-consumption. Variable patterns of cannabinoids or their metabolites in urine were observed. In 30% of the urine samples collected 8 h after ingestion, the presence of a prohibited cannabinoid would have resulted in an unintentional violation of anti-doping regulations.

Simplified quantification of insulin, its synthetic analogs and C-peptide in human plasma by means of LC-HRMS.

The quantification of peptide hormones by means of liquid chromatography (LC) coupled to mass spectrometry (MS) or other techniques (e.g. immunoassays) has been a challenging task in modern analytical chemistry. Especially for insulin, its synthetic analogs, and C-peptide, reliable determinations are urgently needed due to their diagnostic value in the management of diabetes and insulin resistance and because of the illicit use of insulin as a performance-enhancing agent in professional sports or as an effective toxin in forensic toxicology. The concomitant measurement of C-peptide and insulin offers an established tool for the diagnostic workup of hypoglycemia (endogenous vs. exogenous hyperinsulinemia), characterizing hepatic insulin clearance, and the assessment of beta-cell function (insulin secretion). Thus, the present approach offers the possibility to determine human insulin and its synthetic analogs (lispro, glulisine, aspart, glargine metabolite, degludec, detemir, porcine, and bovine) and C-peptide simultaneously after sample preparation utilizing protein precipitation and a mixed-mode cation-exchange solid-phase extraction, and subsequent detection by LC-high resolution MS. The method was fully validated regarding the following parameters: specificity, limit of detection (0.2 ng/mL), limit of quantification (0.6 ng/mL), recovery (40-90%), accuracy (78-128%), linearity, precision (< 21%), carry over, robustness, and matrix effects. The proof-of-concept was shown by analyzing authentic plasma samples from adults with class II obesity and prediabetes collected in the course of an oral glucose tolerance test. All sample preparation steps were controlled by two stable isotope-labeled internal standards, namely [[2 H10 ] Leu B6, B11, B15, B17 ]-insulin, and [[13 C6 ] Leu 26, 30 ] C-peptide.