Elucidating important factors and corresponding method optimization for sensitive detection of small peptide drugs in human urine by solid-phase extraction and UPLC-HRMS: The influence of MS scan modes, protein precipitants, and ammonium formate.

Small peptide hormones are widely used in sports as performance-enhancing substances, making it crucial to develop sensitive analytical methods for their detection in doping control analysis. Various factors significantly affect analytical sensitivity, such as the selection of ultra-performance liquid chromatography (UPLC) mobile phase, high-resolution mass spectrometry (HRMS) scanning modes, and extraction solvents for pretreatment. Herein, comparative study approach was utilized to investigate the sensitivity of each peptide analyte under both full scan and parallel reaction monitoring (PRM) modes of HRMS and assess the effects of some protein precipitants as a part of extraction solvents on solid-phase extraction (SPE).

Gas chromatography properties and mass spectrometry fragmentation of anabolic androgenic steroids in doping control.

This study aimed to investigate the gas chromatographic properties and mass spectrometric fragmentations of anabolic androgenic steroids (AASs) after trimethylsilylated derivatization. A total of 113 AASs were analyzed through gas chromatography-mass spectrometry in the full-scan mode. New fragmentation pathways yielding 129, 143 and 169 ions were analyzed.

A comprehensive and high-throughput screening method for multiple prohibited substances by UPLC-QE Plus-HRMS and HPLC-QQQ-MS in human urine for doping control.

Since the World Anti-Doping Agency's (WADA) Prohibited List is updated on an annual basis, screening methods must be continually adapted to align with these changes. In accordance with Technical Document-MRPL 2022, a newly combined, comprehensive, rapid and high-throughput doping control screening method has been developed for the analysis of 350 substances with different polarities in human urine using ultra-high performance liquid chromatography coupled with Q Exactive Plus Hybrid Quadrupole-Orbitrap mass spectrometer (UPLC-QE Plus-HRMS) and ultra-high performance liquid chromatography coupled with triple quadrupole mass spectrometer (UPLC-QQQ-MS). The limits of detection were in the range of 0.

Quantification of Ephedrine Substances in Human Urine by Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry.

An accurate quantitative method for four prohibited ephedrine substances in human urine has been established, based on ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS). The quantitative bias caused by pretreatment operations and matrix effects was reduced by the dilute and shoot pretreatment method. The good separation of isomers was achieved with the advantages of the UPLC instrument and Agilent Poroshell 120 EC-C8 UPLC column.

Doping control analysis of small peptides in human urine using LC-HRMS with parallel reaction monitoring mode: screening and confirmation.

This study described a reliable analytical method, which combines solid-phase extraction (SPE) with liquid chromatography-high resolution mass spectrometry (LC-HRMS) employing the parallel reaction monitoring (PRM) mode, for screening 41 small peptides and 3 non-peptide growth hormone secretagogues in human urine. Additionally 36 small peptides and 3 non-peptide growth hormone secretagogues were also confirmed in the same way. For the whole screening procedure, the PRM mode was applied to the HRMS detection of small peptides, which reduces the background noise from matrix compounds to a large extent and thus improves the selectivity and reliability of the peptide analytes.

Metabolic Profiles of 5F-MDMB-PICA in Human Urine, Serum and Hair Samples Using LC-Q Exactive HF-MS.

In 2020, 5F-MDMB-PICA (5F-MDMB-2201) was one of the most common synthetic cannabinoids (SCs) identified in drugs seized by the Beijing Drug Control Agency, and it was categorized as Schedule II by the United Nations Office on Drugs and Crime in March 2020. It is difficult to detect 5F-MDMB-PICA in biological matrices due to its fast metabolic rate in vivo. In this work, 5F-MDMB-PICA metabolic profiles were investigated by liquid chromatography--quadrupole exactive high field orbitrap mass spectrometer (LC-Q Exactive HF MS), with accurate mass measurements in human urine, serum and pubic hair.

Enantiomeric analysis of clenbuterol in Chinese people by LC-MS/MS to distinguish doping abuse from meat contamination.

Follow-up investigations are often required for clenbuterol-positive cases. A method to distinguish doping abuse from meat contamination was developed. A total of 26 volunteers were recruited to ingest clenbuterol contaminated-pork and clenbuterol tablets.

Doping control analysis of 13 steroids and structural-like analytes in human urine using Quadrupole-Orbitrap LC-MS/MS with parallel reaction monitoring (PRM) mode.

Anabolic androgenic steroids (AASs) and structural-like substances are commonly prohibited substances found in doping control studies that can be difficult to accurately detect. In the present study, 11 AASs and 2 structural-like substances that are commonly detected were examined. Currently, such analytes are detected using low resolution GC-MS/MS or LC-MS/MS, with detection not always possible.

New long term metabolite in human urine for metenolone misuse by liquid chromatography quadrupole time-of-flight mass spectrometry.

In this study, metenolone metabolic profiles were investigated. Metenolone was administered to one healthy male volunteer. Liquid-liquid extraction and direct-injection were applied to processing urine samples.

A Sensitive Dilute-and-Shoot Approach for the Simultaneous Screening of 71 Stimulants and 7 Metabolites in Human Urine by LC-MS-MS with Dynamic MRM.

A novel, reliable and sensitive liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was developed with dynamic multiple reaction monitoring (dMRM) mode for the simultaneous screening of 71 stimulants and 7 metabolites in human urine using unsophisticated MS instruments (Agilent triple-quadruple 6410 B mass spectrometer). With a known retention time of an analyte, dMRM algorithm monitors each MRM transition only around its expected retention time. Therefore, dMRM enables the maximization of dwell times and provides much higher sensitivity and reproducibility than the conventional multiple reaction monitoring mode (cMRM).

New clostebol metabolites in human urine by liquid chromatography time-of-flight tandem mass spectrometry and their application for doping control.

In this study, clostebol metabolic profiles were investigated carefully. Clostebol was administered to one healthy male volunteer. Urinary extracts were analyzed by liquid chromatography quadrupole time-of-flight mass spectrometry (MS) using full scan and targeted MS/MS techniques with accurate mass measurement for the first time.

New potential biomarkers for mesterolone misuse in human urine by liquid chromatography quadrupole time-of-flight mass spectrometry.

In this paper, mesterolone metabolic profiles were investigated carefully. Mesterolone was administered to one healthy male volunteer. Urinary extracts were analyzed by liquid chromatography quadruple time-of-flight mass spectrometry (LC-QTOFMS) for the first time.

Structural elucidation of new urinary tamoxifen metabolites by liquid chromatography quadrupole time-of-flight mass spectrometry.

In this study, tamoxifen metabolic profiles were investigated carefully. Tamoxifen was administered to two healthy male volunteers and one female patient suffering from breast cancer. Urinary extracts were analyzed by liquid chromatography quadruple time-of-flight mass spectrometry using full scan and targeted MS/MS techniques with accurate mass measurement.

Quantitative analysis of glycerol levels in human urine by liquid chromatography-tandem mass spectrometry.

Glycerol has the latent capacity to act as a plasma volume expander and disguise blood doping practices. Therefore, it has been prohibited in sports as a masking agent by the World Anti-Doping Agency (WADA) since January 2010 and a urinary threshold (1mg/mL) was recommended recently [1]. The purpose of this study was to establish and validate a novel quantitative method for the determination of urinary glycerol concentrations using a liquid chromatography-tandem mass spectrometry approach.

An improved liquid chromatography-tandem mass spectrometric method to quantify formoterol in human urine.

Formoterol is a new threshold substance in the prohibited list 2012 according to World Anti-Doping Agency. Extracted by ethyl acetate using formoterol-D6 as internal standard, formoterol underwent a constant flow rate gradient elution separation in reversed-phase liquid chromatography. Subsequently, mass spectrometry analysis was conducted by tandem mass spectrometry in the multiple reaction monitoring mode.

Mass spectrometric identification and characterization of new clomiphene metabolites in human urine by liquid chromatography-quadrupole time-of-flight tandem mass spectrometry.

Clomiphene, a selective estrogen receptor modulator, is prohibited by World Anti Doping Agency (WADA) out-of-competition and in-competition. As it is extensively metabolized, further investigation of clomiphene metabolic profile will be essential to routine anti-doping analysis. The metabolic pathway and the different metabolites of clomiphene in human urine collected from three healthy volunteers during 1 week were studied by liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOFMS) based on accurate mass measurement.

Mass spectrometric identification and characterization of new fluoxymesterone metabolites in human urine by liquid chromatography time-of-flight tandem mass spectrometry.

In this study fluoxymesterone urinary profiles were investigated by liquid chromatography quadrupole time-of-flight tandem mass spectrometry (LC-QTOFMS) with accurate mass measurement. Twelve metabolites including the parent drug were detected in two fluoxymesterone positive control urine samples. Three parameters were employed for evaluation of the accuracy of the chemical formulae in positive full scan experiment, which contained error between actual and calculated mass weights of prontonated and isotopic molecules together with abundance match between prontonated and isotopic molecules.

Efficient and green synthesis of bis(indolyl)methanes catalyzed by ABS in aqueous media under ultrasound irradiation.

Ultrasound-promoted synthesis of bis(indolyl)methanes catalyzed by ABS via the reaction of indole or N-methylindole with aromatic aldehyde was carried out in excellent yields in aqueous media at 23-25°C, providing a simple and efficient synthesis of these compounds.