Simultaneous determination of simvastatin and simvastatin acid in human plasma using LC-MS/MS
Fan Tang · Zhongguo xiandai yixue/Zhongguo xiandai yixue zazhi · 2012
【Objective】 To establish a simple,sensitive and selective liquid chromatography coupled with electrospray ionization mass spectrometry method for the determination of simvastatin(Ⅰ) and simvastatin acid(Ⅱ).【Methods】 After extraction,using D3 simvastatin(Ⅲ) and D3 simvastatin acid(Ⅳ) as internal standard,solute was separated on symmetry shield,(150 mm × 3.9 mm),RP8,5 μ column with a mobile phase consisting of acetonitrile: 50 mm ammonium acetate,pH 3.0(80 : 20).Detection was performed on an atmospheric pressure ionization single quadruple massspectrometry.The high-performance liquid chromatography(HPLC) system interfaced with the MS/MS system with a Turbo Ion-spray interface.【Results】 Quantification of simvastatin and simvastatin acid were realized by computing peak area ratio(Ⅰ/Ⅲ and Ⅱ/Ⅳ) of the extract analyzed in MRM mode and comparing them with calibration curve(r =0.9994 for simvastatin and r =0.9996 for simvastatin acid).Accuracy and precision for the assay were determined by calculating the intra batch and inter batch variation at four concentration 0.25,0.75,20,60 ng/mL for simvastatin and 0.25,0.75,15,45 ng/ mL for simvastatin acid;the intra batch relative standard deviation(RSD) was less than 15% and ranged from 3.40 to 14.75%,respectively;the inter batch RSD was less than 15% and ranged from 11.59 to 1.47%.The limit of detection was 0.25 ng/mL for simvastatin and 0.25 ng/mL for simvastatin acid in human plasma.【Conclusion】LC-MS/MS can be applied for simultaneous determination of simvastatin and its active metabolites simvastatin acid in human plasma with its simplity and high sensitivity.