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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.

Exhaled breath analysis is an interesting and promising approach for the diagnostics of various diseases. Being non-invasive, convenient and simple, this approach has tremendous potential utility for further translation into clinical practice. In this study, gas chromatography-mass spectrometry (GC-MS) and quartz microbalance sensor-based "electronic nose" were applied for analysis of the exhaled breath of 40 lung cancer patients and 40 healthy individuals. It was found that the electronic nose was unable to distinguish the samples of different groups. However, the application of GC-MS allowed identifying statistically significant differences in compound peak areas and their ratios for investigated groups. Diagnostic models were created using random forest classifier based on peak areas and their ratios with the sensitivity and specificity of peak areas (ratios) of 85.7-96.5% (75.0-93.1%) and 73.3-85.1% (90.0-92.5%) on training data and 63.6-75.0% (72.7-100.0%) and 50.0-69.2% (76.9-84.6%) on test data, respectively. The exhaled breath samples of lung cancer patients and healthy volunteers could be distinguished by GC-MS with the use of individual compounds, but application of their ratios could help to determine specific differences between investigated groups and the level the influence of individual metabolism features alternating from one person to another as well as daily instrument reproducibility deviations. The electronic nose has to be significantly improved to apply it to lung cancer diagnostics of exhaled breath analysis and the influence of water vapour has to be lowered to increase the sensitivity of the sensors to detect lung cancer biomarkers.

Aim: The purpose of this study was to estimate volatile organic compounds (VOCs) ability to distinguish exhaled breath samples of lung cancer patients and healthy volunteers and to assess the effect of smoking status and gender on parameters. Patients & methods: Exhaled breath samples of 40 lung cancer patients and 40 healthy individuals were analyzed using gas chromatography–mass spectrometry. Influence of other factors on the exhaled breath VOCs profile was investigated. Results: Some parameters correlating with the disease status were affected by other factors. Excluding these parameters allows creating a logistic regression diagnostic model with 83% sensitivity and 81% specificity. Conclusion: Influence of other factors on the exhaled breath VOCs profile has to be taken into account to avoid misleading results.

В данной статье рассмотрен случай внезапной смерти, вероятной причиной которой стало сочетание употребления алкоголя, эфедрина и анаболических стероидов в сочетании с систематическими тяжелыми тренировками. В результате посмертной экспертизы, проведенной с использованием ультравысокоэффективной жидкостной хроматографии в сочетании с тандемным масс-спектрометрическим детектированием, газовой хромато-масс-спектрометрии с источником электронной ионизации и газовой хроматографии с пламенно-ионизационным детектором и дозированиемравновесной паровой фазы.

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.

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., Analytical chemistry; Biomedical engineering; Cancer research; volatile organic compounds, exhaled breath analysis, tumor tissue analysis, lung cancer, thermal desorption, GC-FID, GC-MS

A procedure for the quantification of steroid hormones of various classes in human urine (androgens, estrogens, progestins, corticosteroids) has been described consisting of sample preparation by means of dispersive liquid-liquid extraction after enzymatic hydrolysis with β-glucuronidase from E. Coli followed by ultra-high performance liquid chromatography–high resolution mass spectrometry (quadrupole time-of-flight) detection. Both one-variable-at-a-time and multivariate approaches (full factorial and Box-Behnken designs) were applied to optimize sample preparation conditions. The procedure was validated using synthetic urine in the concentration range of 0.25–500 ng/mL. Then, it was applied to the analysis of real urine samples and the results were compared with those of a common liquid-liquid extraction procedure. The results obtained proved its applicability to the quantification of steroid hormones in human urine with high sensitivity and accuracy.

A method for the determination of catecholamine derivatives in human urine is proposed that includes the derivatization of target compounds on a solid-phase extraction cartridge and determination of the analytes by a UHPLC method with tandem mass-spectrometric detection. 9-Fluorenyl-methoxycarbonyl chloride was used as the derivatization agent. The limits of detection for the analytes were 2.5 ng mL−1 for 9-fluorenyl-methoxycarbonyl-adrenaline, 5 ng mL−1 for 9-fluorenyl-methoxycarbonyl-octopamine, and 25 ng mL−1 for 9-fluorenyl-methoxycarbonyl-dopamine. The proposed procedure was tested on real samples obtained from volunteers.

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.

A simple and sensitive procedure for the quantification of two commonly abused aryl-propionamide-derived selective androgen receptor modulators (SARMs), namely S-4 (GTx-007, andarine) and S-22 (GTx-024, MK-2866, ostarine, enobosarm), has been described. Urine samples were prepared for analysis by means of a dispersive liquid-liquid microextraction using methanol and chloroform as dispersive and extracting solvents, respectively. Factors that might influence the extraction process as well as their optimum conditions were evaluated by Box-Benken and central composite designs. After extraction, the analytes were quantified by UHPLC-MS/MS. The proposed procedure was validated on human urine samples. As a result, for both SARMs the detection limits were observed at 0.05 ng/mL and calibration curves were linear in the concentration range of 0.25-50 ng/mL with the coefficient of determination of 0.998.