摘要
A sensitive, accurate and selective liquid chromatography-tandem mass spectrometry method （LC-MS/MS） was developed and validated for the simultaneous quantitation of atorvastatin （AT） and its equipotent hydroxyl metabolites, 2-hydroxy atorvastatin （2-AT） and 4-hydroxy atorvastatin （4-AT）, in human plasma. Electrospray ionization （ESI） interface in negative ion mode was selected to improve the selectivity and the sensitivity required for this application. Additionally, a solid phase extraction （SPE） step was performed to reduce any ion-suppression and/or enhancement effects. The separation of all compounds was achieved in less than 6 min using a C18 reverse-phase fused-cores column and a mobile phase, composed of a mixture of 0.005%formic acid in water：acetonitrile：methanol （35：25：40, v/v/v）, in isocratic mode at a flow rate of 0.6 mL/min. The method has lower limit of quantitation （LLOQ） of 0.050 ng/mL for all analytes. The method has shown tremendous reproducibility, with intra-and inter-day precision less than 6.6%, and intra- and inter-day accuracy within 74.3% of nominal values, for all analytes, and has proved to be highly reliable for the analysis of clinical samples.
A sensitive, accurate and selective liquid chromatography-tandem mass spectrometry method （LC-MS/MS） was developed and validated for the simultaneous quantitation of atorvastatin （AT） and its equipotent hydroxyl metabolites, 2-hydroxy atorvastatin （2-AT） and 4-hydroxy atorvastatin （4-AT）, in human plasma. Electrospray ionization （ESI） interface in negative ion mode was selected to improve the selectivity and the sensitivity required for this application. Additionally, a solid phase extraction （SPE） step was performed to reduce any ion-suppression and/or enhancement effects. The separation of all compounds was achieved in less than 6 min using a C18 reverse-phase fused-cores column and a mobile phase, composed of a mixture of 0.005%formic acid in water：acetonitrile：methanol （35：25：40, v/v/v）, in isocratic mode at a flow rate of 0.6 mL/min. The method has lower limit of quantitation （LLOQ） of 0.050 ng/mL for all analytes. The method has shown tremendous reproducibility, with intra-and inter-day precision less than 6.6%, and intra- and inter-day accuracy within 74.3% of nominal values, for all analytes, and has proved to be highly reliable for the analysis of clinical samples.
