Development of early noninvasive methods for lung cancer diagnosis is among the most promising technologies, especially using exhaled breath as an object of analysis. Simple sample collection combined with easy and quick sample preparation, as well as the long-term stability of the samples, make it an ideal choice for routine analysis. The conditions of exhaled breath analysis by preconcentrating volatile organic compounds (VOCs) in sorbent tubes, two-stage thermal desorption and gas-chromatographic determination with flame-ionization detection have been optimized. These conditions were applied to estimate differences in exhaled breath VOC profiles of lung cancer patients and healthy volunteers. The combination of statistical methods was used to evaluate the ability of VOCs and their ratios to classify lung cancer patients and healthy volunteers. The performance of diagnostic models on the test data set was greater than 90 % for both VOC peak areas and their ratios. Some of the exhaled breath samples were analyzed using gas chromatography coupled with mass spectrometry (GC-MS) to identify VOCs present in exhaled breath at lower concentration levels. To confirm the endogenous origin of VOCs found in exhaled breath, GC-MS analysis of tumor tissues was conducted. Some of the VOCs identified in exhaled breath were found in tumor tissues, but their frequency of occurrence was significantly lower than in the case of exhaled breath.

A simple and sensitive procedure for the quantification of meldonium in milk and meat by UHPLC-HRMS is presented. Some products were investigated to contain this substance due to using a veterinary drug called “Emidonol”. According to the instruction for this drug, it can be used for injection (for cows) and as an additive in drinking water for chickens. Although meldonium is not a threat for human health, it is strictly prohibited in professional sports according to WADA Prohibited List. Sample preparation conditions were optimized for both matrices that allowed to eliminate matrix effects and achieve reproducible and accurate results. Protein precipitation with dilution were applied for milk samples, while chicken meat and liver were homogenized with quartz sand to achieve satisfactory meldonium recovery. The results of milk and meat samples analysis purchased at the farmers’ fair are presented in this article. Meldonium concentration in raw milk was investigated to be up to 880 ng/mL. However, pasteurization can be used for partial cleanup from meldonium (up to 2 times). The same research was conducted for chicken meat and liver. Thermal treatment shows a good result for a meat cleanup. The proposed method was partially validated, limits of detection and quantification were established for each matrix.

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Exhaled breath analysis is interesting and promising approach for diagnostics of various diseases. Being noninvasive, convenient and simple, this approach has tremendous potential utility for further translation into clinical practice....

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