Evaluation of multiple reaction monitoring cubed performed by a quadrupole-linear ion trap mass spectrometer for quantitative determination of 6-sulfatoxymelatonin in urine.

Liquid chromatography (LC) - mass spectrometry quantitative analysis of substances in biological samples is usually performed in the multiple reaction monitoring (MRM) variant. In complex biological matrices, strong interferences can be observed when using the LC-MRM method. Interference levels can be significantly reduced by using LC - multiple reaction monitoring cubed (MRM3). 6-sulfatoxymelatonin (6-SM) is a metabolite of melatonin, an important regulator of many biological processes. The quantitative analysis of 6-SM in urine allows monitoring of the melatonin level in the blood. The aim of the present work was to evaluate the LC-MRM3 method for the quantitative determination of 6-SM in urine. We found that for 6-SM in aqueous solutions, under some parameters of the MRM3 experiment, the effect of degradation of the MRM3 signal is observed. When analyzing 6-SM in urine, this signal degradation effect was significantly reduced. We have shown that optimization of such parameters of the MRM3 method as the linear ion trap fill time, the number of scans to sum, and the range of triple-stage scan allows obtaining the LC-MRM3 method, which is comparable to the LC-MRM in sensitivity and significantly exceeds it in selectivity.

Skin Microbiota in Contact Sports Athletes and Selection of Antiseptics for Professional Hygiene.

BACKGROUND: The aim of this study was to assess changes in skin microbiota of wrestlers during training sessions and to determine the sensitivity of hemolytic bacterial isolates to antiseptics. METHODS: The main skin bacterial isolates obtained from the skin of 15 wrestlers were identified by cultivation method, with the following MALDI Biotyper and 16S rRNA gene sequencing methods. The sensitivity of hemolytic isolates to antiseptics (Veltosept-2, Cutasept F, Chlorhexidine, Miramistin, and Hydrogen Peroxide) was evaluated by measuring the size of bacterial growth inhibition zone on agar plates. RESULTS: Opportunistic bacteria of the species Bacillus cereus, Staphylococcus aureus, S. epidermidis, and S. saprophyticus were the most commonly found species in skin microbiota of wrestlers before and after training sessions. Representatives of all these species mostly had a hemolytic activity. An alcohol-containing antiseptic Veltosept-2 showed the strongest inhibitory effect on the bacterial isolates of athletes' skin microbiota most frequently detected in this study. CONCLUSIONS: The general increase in the bacterial colonization of wrestlers' skin, as well as the presence of hemolytic forms of opportunistic bacteria in cutaneous microbiota, indicates dysbiotic changes and a decrease in the protective features of the host organism. Veltosept-2 application can reduce the incidence of skin infections in contact sports athletes with the highest efficiency.