Quantification of steroid hormones in human urine by DLLME and UHPLC-HRMS detection.

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 ß-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.

Investigation of different approaches for exhaled breath and tumor tissue analyses to identify lung cancer biomarkers.

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 novel approach to the quantification of urinary aryl-propionamide-derived SARMs by UHPLC-MS/MS.

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.