The Application Studies Of Organic Mass Spectrometry On Drug Analysis

Mass spectrometry(MS)could not only provide high sensitivity and reliable detection for various samples,but also offer much information about the structure and identity of analytes.Rapid analysis of complicated sample is always one of the goals of mass spectrometric scientists and an important development trendency of mass spectrometric technique.Based on its rapid,sensitive,accurate character and easy coupling with other analytical technique,the development of organic mass spectrometry shows the advantages in the widely applied area.In the present study, several applications were developed and validated for the determination of four different drug in human plasma by ion trap mass spectrometer or tri-quadrupole tandem mass spectrometer coupled with high-performance liquid chromatography.1.Based on LC/MS technique,a simple and rapid method for the quantification of azithromycin in human plasma is developed.Herein a simple sample preparation method of protein precipitation with methanol was employed.The calibration curves were linear over the concentration range 4.69-600ng/mL and the recovery ranged from 87.41 to 99.97%for the analyte.This method was applied to a biocquivalence study after administration of 500mg azithromycin to 20 healthy voluntecrs.2.A simple and sensitive LC-MS/MS method for the quantification of troxerutin in human plasma is developed and validated.Perchloric acid was employed for protein precipitation.Due to the high polarity,troxerutin could only achieve suitable retention on a Phenomenex Synergi Fusion RP column.The lower limit of quantification was 31.25pg/mL for the analyte,precision below 12.28%and relative error was not more than±12.8%.This method was applied to a bioequivalence study after an administra- tion of 300mg troxerutin to 18 healthy volunteers.3.A sensitive LC-MS/MS method for the determination of levonorgestrel in human plasma using liquid-liquid extraction(LLE)with ethyl acetate,was developed. It was found that levenorgestrel yielded strong retention on C₁₈column,and higher signal-to-noise ratio was observed using acetonitrile as the mobile phase than using methanol as the mobile phase.The proposed method was validated over the concentration range 0.625-40ng/mL and applied successfully to the analyses of samples obtained from a bioequivalence study.4.Simultaneous determination of hydrochlorothiazide and valsartan in human plasma by LC-MS/MS method was described,which was proved to be economical and efficient.The method was found to be suitable for application to a bioequivalence study after oral administration of dispersible tablet containing 12.5mg hydrochlorothiazide and 80mg valsartan to 20 healthy volunteers.