Simultaneous determination of diazepam,nordiazepam and oxazepam in hair by HPLC
Objective:To establish an HPLC analysis method for the determination of diazepam,nordiazepam and oxazepam in hair samples.Methods:The determination of drug content and related substances was performed by high performance liquid chromatography(HPLC).Ultrasonic method combined with liquid-liquid extraction method was used as the pretreatment method.The chromatographic column was Athena C18-WP column(250 mm ×4.6 mm,5 μm);the mobile phase was the mixture of methanol:0.02 mol·L-1 sodium dihydrogen phosphate(adjusted to pH 3.4 with phosphoric acid):acetonitrile(30∶43∶27,v/v/v)in an isometric elution;the column temperature was 50 ℃;the flow rate was 0.7 mL·min-1;the running time was 30 min;the injection volume was 20 μL.The detection wavelength was 254 nm.The internal standard was clonazepam.Results:The linearity of all the analytes were good in the concentration range of 0.1 to 25 ng·mg-1(r＞0.995).The limit of quantitative was 0.1 ng·mg-1 and the limit of detection was 0.05 ng·mg-1.The intra-batch accuracies were 88.2％-103.9％(n=6)and the inter-batch accuracies were 88.5％-106.2％with imprecisions ≤9.19％.The recoveries were stable for three anlytes,which met the requirement of methodology.The present method was applied to the authetic hair samples,in which the concentrations of diazepam,norazepam and oxazepam were(0.307±0.016)ng·mg-1,(0.244±0.012)ng·mg-1 and(0.478±0.053)ng·mg-1 respectively.Besides,Cnorazepam/Cdiazepam was 0.795,which was in consistent with the literature reported.Conclusion:The es-tablished HPLC method is fast and easy to operate,with good reproducibility,applicability,and reliability.
NETL
NSTL
万方数据
