Search

Abstract: A simple and rapid assay based on hydrophilic interaction liquid chromatography with tandem mass spectrometry has been first developed and validated for simultaneous determination of caprolactam (CA) and 6-aminocaproic acid (6-ANCA) in human urine using 8-aminocaprylic acid as internal standard. A 20μL aliquot of urine was injected directly into the liquid chromatography tandem mass spectrometry (LC–MS–MS) system. The analytes were separated on a Phenomenex Luna HILIC column with gradient elution. Detection was performed on Triple Quadrupole LC–MS in positive ions multiple reaction monitoring mode using electrospray ionization. The calibration curves were linear (r 2 ≥0.995) over the concentration range from 62.5 to 1250ng/mL for CA and 31.25 to 1000ng/mL for 6-ANCA. The detection limits of CA and 6-ANCA were 62.5 and 15.6ng/mL, respectively. The intra-day and inter-day precisions were within 8.7% and 9.9%, respectively. The intra-day and inter-day accuracy were between 5.3% and 3.5%, and between 6.1% and 6.6%, respectively. The method proved to be simple and time efficient, and was successfully applied to evaluate the kinetics of caprolactam in one unusual case of caprolactam poisoning. [Copyright &y& Elsevier]

Abstract: The urine specimens of numerous athletes were found to be positive for mephentermine both in-competition and out-of-competition in Taiwan. The donor of one specimen claimed she had only taken Mucaine® (contains oxethazaine) for relieving symptomatic peptic ulcer and gastritis. Oxethazaine is not included in the prohibited list of the World Anti-Doping Agency; however, its metabolized compounds, mephentermine and phentermine, are included in that list. This study applied LC–MS–MS to analyze the excretions of three volunteers who ingested oxethazaine and presented positive results for mephentermine and/or phentermine. Thus, oxethazaine is the source of mephentermine and phentermine. Moreover, the results showed that 48 brands of gastric medicines containing oxethazaine were legally imported or locally manufactured in Taiwan, information which could be useful for limiting the misuse of oxethazaine by athletes. The data suggested that the sports associations should warn athletes about the risks of taking oxethazaine. [Copyright &y& Elsevier]