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In clinical practice, exhaled air analysis is a promising approach for diagnosing lung cancer due to a possibility of rapid and noninvasive sampling. We analyzed the exhaled air of 80 patients with lung cancer to identify differences in the profiles of volatile organic compounds in patients with different histological types and localization of cancer using gas chromatography–mass spectrometry. Some volatile organic compounds and their ratios have been identified, statistically signficant differences in concentrations of which have been found in samples with different localization and histological type.

The results of applying various statistical methods of analysis to the processing of a large array of data obtained using a validated method of gas chromatographic analysis with tandem mass-spectrometric detection are considered. The findings are an integral part of a human steroid profile, and they are used as characteristics in doping control laboratories. The applicability of statistical methods of analysis to detect the degradation of urine samples in the course of storage based on chemometric approaches is considered; the factors that are most influenced during the degradation of urine samples are identified, and the capabilities and limitations of various statistical methods in operations with large data arrays are demonstrated.

A procedure for the determination of AICAR (5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside, Acadesine), an AMP-activated protein kinase agonist prohibited by the World Anti-Doping Agency since 2009, in urine has been proposed including sample clean-up from matrix components by means of solid-phase extraction and detection of the analyte by ultra-high performance liquid chromatography–tandem mass-spectrometry with heated electrospray ionization ion source. Due to the endogenous nature of AICAR, standard additions approach was applied to quantify AICAR and evaluate matrix effects. The limit of detection was 5 ng/mL, calibration curves were linear in the concentration range of 50–5000 ng/mL. The proposed procedure was applied to the analysis of real samples.

The possibility of determining volatile organic compounds contained in exhaled air by concentrating them in sorption tubes, two-stage thermal desorption, and gas-chromatographic determination with a flame-ionization detector on various chromatographic columns was studied. It has been established that Tenax TA is an optimal sorbent for the preconcentration, and the highest separation efficiency is achieved on a PLOT CP-Porabond-Q column. The preconcentration of analytes with no breakthrough was achieved upon passing a 0.5-L sample through a sorbent at a rate of 200 mL/min.

A procedure for the determination of a selective androgen receptor modulator andarine (S-4) and a nonpeptide growth hormone secretagogue ibutamoren (MK-677) in urine has been developed including sample preparation by the “dilute-and-shoot” procedure, separation of analytes by ultra-high performance liquid chromatography in the gradient elution mode, and mass-spectrometric detection with heated electrospray ionization. The limits of detection are in the range of 0.5–2.5 ng/mL, the calibration curves are linear in the range of 2.5–250 ng/mL for andarine and 5–250 ng/mL for ibutamoren. The proposed procedure was used for the analysis of urine samples obtained from volunteers after a single administration of these drugs containing 15 mg of active substances.