Determination of testosterone concentrations in rat plasma using liquid chromatography–atmospheric pressure chemical ionization mass spectrometry combined with ethyl oxime and acetyl ester derivatization

Simultaneous quantitation of testosterone, estradiol, ethinyl estradiol, and 11‐ketotestosterone in fathead minnow fish plasma by liquid chromatography/positive atmospheric pressure photoionization tandem mass spectrometry

“…Recently, the sensitive and selective LC/MS/MS (including APPI, APCI and ESI) technique has been widely used for simultaneous or separate quantitation of TES, E2, and EE2, and 11‐KT in plasma or in environmental samples 24–26, 32, 34–41. Most of these published methods require large amounts of plasma (ranging from 50 to 500 µL) and liquid‐liquid extraction steps.…”

Determination of salivary 17-ketosteroid sulfates using liquid chromatography–electrospray ionization-mass spectrometry

“…To determine the extent to which the saliva matrix affects the quantification, the slopes of the above calibration curves were compared to those of the curves prepared with the matrix sample [11,13]. As a result, the slopes of the latter were (2.245 ± 0.095) × 10 −3 (mean ± S.D., n = 5, CV 4.2%) for DHEAS, (2.627 ± 0.085) × 10 −3 (CV 3.2%) for AS and (3.162 ± 0.065) × 10 −3 (CV 2.1%) for EAS, which were practically identical to the slopes of the curves constructed using the standard solutions.…”

Comparison of three derivatization reagents for the simultaneous determination of highly hydrophilic pyrimidine antitumor agents in human plasma by LC–MS/MS

“…Along with many successful applications, a number of limitations of API have been reported to analyze some chemicals, which cannot produce free gas ions efficiently or which have low proton affinity [1][2][3][4].…”