Measurement Uncertainty and Validation for Quantitation of Salbutamol in Human Urine by Gas Chromatography-Tandem Mass Spectrometry.

A simple, rapid, sensitive and specific gas chromatography-tandem mass spectrometry (GC-MS/MS) method was developed for quantitation of salbutamol in human urine using salbutamol-d3 as the internal standard. The processing of urines samples includes deconjugation with enzymatic hydrolysis, solid phase extraction procedure utilizing XAD2 column and liquid-liquid extraction accompanied by the derivatization by means of MSTFA/IODO-TMS/DTE mixture. The GC column was a HP Ultra-1 (17 m × 0.22 mm × 0.11 µm) used to separate the peak of interest. The data for GC-MS/MS were acquired and processed utilizing GC Labs Solution and Insight GCMS Software. The detection of spectra was performed on TQ 8050. This method included a chromatographic run of 13.67 min and the linearity was found over the concentration range of 250-2000 ng/mL with a regression coefficient (r2) of 0.99. The coefficient of variation for intra and interday assay precision was between 1.85 and 2.85% and the accuracy was between 95.50 and 107.04% for low quality control (QC), medium QC and high QC. The recovery was adequate to reliable detect the analyte at or below the level recommended by the World Anti-Doping Agency i.e., threshold 1000 ng/mL. The limit of detection and limit of quantification were found to be 10 and 100 ng/mL, respectively. The expanded measurement uncertainty (Uexp%) was found to be 8.28%.

Process development for the total synthesis of the novel drug metabolite Carboxy toremifene as a standard reference material along with characterization and purity assessment for the Antidoping quality Control Purposes.

Tamoxifen and toremifene are two selective estrogen receptor modulators (SERMs) commonly used to treat breast cancer in women. Toremifene is well-known as a triphenylethylene derivative. Carboxy toremifene is a common metabolite of toremifene and tamoxifen. Since 2005, the World Anti-Doping Agency (WADA) has banned the SERMs category during in and out of competition. These substances are in the S4 category in the WADA prohibited list as "agents with anti-oestrogenic activity." However, there is no commercially accessible carboxy toremifene reference material in the market. This research highlights the novel synthetic procedure, the development of a carboxy toremifene HPLC method, and validation, along with detailed characterization using advanced analytical techniques using 1 H NMR, HRMS, FT-IR-ATR and UV-visible spectroscopy. RP-HPLC-DAD method was developed and validated to assess the purity of carboxy toremifene. Developed reference material has shown 100% purity. Therefore, we recommend that this synthesized carboxy toremifene may be used as reference material to strengthen the WADA-accredited lab to maintain a clean sports mission during sports competitions.