Correction of the urinary testosterone to epitestosterone ratio measurement in antidoping analyses by chromatographic and mass spectrometric techniques.

The ratio of testosterone (T) to epitestosterone (E) determined in urine samples is the main biomarker used to prove T and precursors abused by athletes. Analytically, the correction of the ratio is required by the World Anti-Doping Agency. This work describes a series of experiments aimed to study when it is appropriate to correct the T/E ratio value, using different mass spectrometric techniques since only reports on GC-MS exist. Analyses using external calibrators, controls, and routine samples were performed by three different techniques GC-MS, GC-MSn , and LC-MSn . A statistical comparison of the T/E was performed after the application of two corrections previously published: Isotopic contribution peak area correction (corr_1) and use of a verified internal deuterated internal standard (TD3/ED3) correction (corr_2) and the ratio based on T and E concentrations. The use of external calibration samples introduces biases that influence not only the T and E concentrations but also the T/E ratio, even when both methods of correction are applied. The correction after applying corr_1 method barely contributed to the accuracy of the T/E calculation. Nevertheless, the application of the corr_2 method increased the accuracy between 5% and 6% when comparing theoretical and experimental T/E values. Finally, the best results were obtained by the ratio calculated directly from the estimated concentrations of T and E. Attention must be paid when the T/E is measured by LC-MSn since different acquisition modes produced significantly different results, even in MS/MS when the same transition is used for T and E.

Carbon isotope ratio of endogenous urinary steroids of the Cuban population of athletes studied for doping purposes.

The aim of this work was to validate the gas chromatography/combustion/isotope ratio mass spectrometry method in Havana Antidoping Laboratory and verify its implementation with a study of the Cuban population. The method was precise and accurate inside the linear working range; the limit of quantification and the uncertainty were compliant with TD2019IRMS. The study of the Cuban population showed no differences in δ13 C values between females and males. Only three values of Δδ13 C showed significant differences between sexes (PD-T, OHA-T, and 11-keto-Et-T). The values of δ13 C between -17.8‰ and -21.2‰ (upper and lower limits based on normal distribution) were consistent with other populations where C4 plant derivatives prevail in the diet.

"Application of the ultra micro analytical system (SUMA) technology for the detection of urinary hCG in antidoping control".

The Ultra Micro Analytical System (SUMA) is an ELISA-based analytical platform, developed andmanufactured by the Cuban Immunoassay Center (IC), which is primarily used in clinical medicine applications. In this article, we describe the validation of the UMELISA HCG kits, which are based on SUMA, as a pre-screening procedure for the detection of human Chorionic Gonadotrophin (hCG) in urine for anti-doping purposes. Validation of assay performance parameters showed satisfactory results, in accordance with the criteria established by the World Anti-Doping Agency (WADA): intra-assay repeatability (6.7-9.7%), inter-assay reproducibility (7.8-10.5%), accuracy (91-98%), limit of detection (2.7 IU/L), and linearity. Relative sensitivity and specificity and Predictive Positive and Negative Values were used to evaluate the Efficacy showing a value of 97.6%. A Kappa Index analysis was applied to check agreement with the commercially available, reference assay COBASe411 (Roche), which is often applied in WADA-accredited anti-doping laboratories for measurement of intact (heterodimeric) hCG in urine. UMELISA HCG kits are considered as fit for anti-doping control purposes.

Cuantificación simultánea de andrógenos, estrógenos, corticoides y pregnanos mediante cromatografía de gases acoplada a espectrometría de masas / Simultaneous quantification of androgens, estrogens, corticoids and pregnanes thorugh the gas chromatography-mass spectrometry method

Introducción: la evaluación de hormonas en pacientes de endocrinología y bioquímica clínica, entre otros, se realiza actualmente por métodos de inmunoensayo con las desventajas inherentes a este tipo de análisis (ejemplo: reacciones cruzadas). Con la aplicación de la espectrometría de masas acoplada a cromatografía de gases es posible aumentar la sensibilidad y especificidad de los análisis. Objetivo: validar un ensayo que permita la cuantificación de 21 hormonas mediante la técnica de cromatografía de gases-espectrometría de masas con propósitos de pesquizaje. Métodos: el ensayo se basó en una extracción en fase sólida con columnas DetectabuseTM y posterior extracción líquido-líquido a pH básico. Los derivados trimetilsilil se analizaron con un cromatógrafo de gases Hewlett-Packard 6890 acoplado a un espectrómetro de masas cuadrupolar serie 5973. La columna capilar fue HP Ultra-1 (17 m x 0,20 mm x 0,11 µm). La adquisición fue realizada en modo SIM (monitoreo selectivo de iones). Resultados: los resultados del proceso de validación cumplieron con los criterios de aceptación de una manera adecuada correspondiente a un método con propósitos de pesquizaje. El método resultó ser específico para los 21 compuestos estudiados, lineal (r2= 0,900-0,996) y preciso (CV entre 1,4-9,6 por ciento). El rendimiento de extracción se mantuvo entre 69-117 por ciento. La robustez con variación de disolvente mostró recobrados entre 69-139 por ciento. Conclusiones: los resultados demuestran que la técnica analítica desarrollada para la cuantificación de los 21 compuestos esteroidales en orina, es exacta, específica, lineal, precisa y robusta para su aplicación con propósitos de pesquizaje en estudios endocrinológicos clínicos(AU)

Introduction: the evaluation of hormones on endocrinology and clinical biochemistry patients, among others, is presently performed, using inmunoassays with its intrinsic disadvantages such as cross reactions. The application of gas chromatography coupled to mass spectrometry allows increasing the sensitivity and specificity of this analysis. Objective: to validate an assay for quantitation of 21 hormones by the analytical technique of gas chromatography - mass spectrometry for screening purposes. Methods: the assay followed a solid-phase extraction using DetectabuseTM columns and subsequently liquid-liquid extraction at basic pH. Trimethylsilyl derivatives were evaluated on Hewlett-Packard 6890 gas chromatograph coupled to serial 5973 quadrupolar mass spectrometer. The capillary column was HP Ultra-1 (17 m x 0.20 mm x 0.11 µm). Data was gathered following SIM mode (selective ion monitoring). Results: the results of the validation process adequately fulfilled the acceptance criteria for screening purposes. The assay proved to be specific for all studied compounds, linear (r2= 0.900-0.996) and precise (VC 1.4-9.6 percent). The extraction yield was kept at 69-117 percent. The robustness assay with varying dissolvent showed extraction yields ranging 69-139 percent. Conclusions: results of the validation process show that the developed assay to simultaneously quantify 21 steroidal compounds in urine is exact, linear, precise, robust and specific for its application in clinical endocrine studies for screening purposes(AU)

Cuantificación simultánea de andrógenos, estrógenos, corticoides y pregnanos mediante cromatografía de gases acoplada a espectrometría de masas / Simultaneous quantification of androgens, estrogens, corticoids and pregnanes thorugh the gas chromatography-mass spectrometry method

INTRODUCCIÓN: la evaluación de hormonas en pacientes de endocrinología y bioquímica clínica, entre otros, se realiza actualmente por métodos de inmunoensayo con las desventajas inherentes a este tipo de análisis (ejemplo: reacciones cruzadas). Con la aplicación de la espectrometría de masas acoplada a cromatografía de gases es posible aumentar la sensibilidad y especificidad de los análisis. OBJETIVO: validar un ensayo que permita la cuantificación de 21 hormonas mediante la técnica de cromatografía de gases-espectrometría de masas con propósitos de pesquizaje. MÉTODOS: el ensayo se basó en una extracción en fase sólida con columnas DetectabuseTM y posterior extracción líquido-líquido a pH básico. Los derivados trimetilsilil se analizaron con un cromatógrafo de gases Hewlett-Packard 6890 acoplado a un espectrómetro de masas cuadrupolar serie 5973. La columna capilar fue HP Ultra-1 (17 m x 0,20 mm x 0,11 µm). La adquisición fue realizada en modo SIM (monitoreo selectivo de iones). RESULTADOS: los resultados del proceso de validación cumplieron con los criterios de aceptación de una manera adecuada correspondiente a un método con propósitos de pesquizaje. El método resultó ser específico para los 21 compuestos estudiados, lineal (r2= 0,900-0,996) y preciso (CV entre 1,4-9,6 por ciento). El rendimiento de extracción se mantuvo entre 69-117 por ciento. La robustez con variación de disolvente mostró recobrados entre 69-139 por ciento. CONCLUSIONES: los resultados demuestran que la técnica analítica desarrollada para la cuantificación de los 21 compuestos esteroidales en orina, es exacta, específica, lineal, precisa y robusta para su aplicación con propósitos de pesquizaje en estudios endocrinológicos clínicos(AU)

INTRODUCTION: the evaluation of hormones on endocrinology and clinical biochemistry patients, among others, is presently performed, using inmunoassays with its intrinsic disadvantages such as cross reactions. The application of gas chromatography coupled to mass spectrometry allows increasing the sensitivity and specificity of this analysis. OBJECTIVE: to validate an assay for quantitation of 21 hormones by the analytical technique of gas chromatography - mass spectrometry for screening purposes. METHODS: the assay followed a solid-phase extraction using DetectabuseTM columns and subsequently liquid-liquid extraction at basic pH. Trimethylsilyl derivatives were evaluated on Hewlett-Packard 6890 gas chromatograph coupled to serial 5973 quadrupolar mass spectrometer. The capillary column was HP Ultra-1 (17 m x 0.20 mm x 0.11 µm). Data was gathered following SIM mode (selective ion monitoring). RESULTS: the results of the validation process adequately fulfilled the acceptance criteria for screening purposes. The assay proved to be specific for all studied compounds, linear (r2= 0.900-0.996) and precise (VC 1.4-9.6 percent). The extraction yield was kept at 69-117 percent. The robustness assay with varying dissolvent showed extraction yields ranging 69-139 percent. CONCLUSIONS: results of the validation process show that the developed assay to simultaneously quantify 21 steroidal compounds in urine is exact, linear, precise, robust and specific for its application in clinical endocrine studies for screening purposes(AU)