Simultaneous determination of clomipramine and four benzodiazepines in human plasma by HPLC-DAD after solid phase extraction / 中国药理学通报

ABSTRACT

Aim To establish a novel,highly sensitive,rapid and cost-effective HPLC method to simultaneously determine tri-cyclic antidepressant clomipramine and four benzodiazepines of diazepam,alprazolam,clonazepam,oxazepam in human plasma pretreated by solid phase extraction.Methods The assay was achieved by using C8 column (4.6 mm ×1 50 mm,5 μm)kept at 45 ℃,mobile phase 73.226.8 V/V (50 mmol·L -1 ,pH 3.0 phosphate bufferacetonitrile)with flow rate of 1 .2 ml· min -1 ,and UV detection was set at λ220 nm.Solid phase ex-traction was performed on C1 cartridges.Results The calibra-tion curve was demonstrated to be linear (r >0.9994)in the ranges of 5 ~200 μg·L -1 for alprazolam and clonazepam,1 0 ~500 μg·L -1 for diazepam,20 ~500 μg· L -1 for clomipra-mine,and 7.5 ~2000 μg·L -1 for oxazepam;the limit of detec-tion (LOD)was 1 .5,1 .4,3.0,5.5 and 2.2 μg·L -1 for al-prazolam,clonazepam,diazepam,clomipramine and oxazepam respectively.Intra-day and inter-day precision revealed a coeffi-cient of variation of 2.2% ~1 2.6% and 2.1 % ~1 3.2%,re-spectively.Extraction yield ranged from 81 .1 % ~1 00.1 % for all analytes.Conclusion The developed method is accurate, reproducible,convenient,and suitable for routine therapeutic drug monitoring of clomipramine and the four benzodiazepines.