Simultaneous Determination of Six Benzodiazepines in Spiked Soft Drinks by High Performance Liquid Chromatography with Ultra Violet Detection (HPLC-UV)

A high performance liquid chromatographic method with ultra violet detection for simultaneous analysis of six benzodiazepines (BZDs) (chlordiazepoxide, diazepam, clonazepam, midazolam, flurazpam, and lorazepam) has been developed for forensic screening of adulterated non-alcoholic drinks. Samples were analyzed after a simple procedure for preparation using pH adjustment and filtering. Isocratic elution on a C18 column (250mm x 4.6 mm, 5 mu m) in the temperature 45 degrees C with a mobile phase consisting of 15mM phosphate buffer: methanol (50:50 v/v) at a flow rate 1.4 mL/min has been done. The column eluent was monitored with a UV detector at 245 nm. This allowed a rapid detection and identification as well as quantization of the eluting peaks. Calibration curves for all drugs in the range of 0.5-10 mu g/mL that all the linear regression and has more than 0.996. Recovery rates for the BZDs were in the range 93.7-108.7%. The limits of detection were calculated between 0.01-0.02 mu g/ mL. Also, the limits of quantification were 0.03-0.05 mu g/mL. Within-day and between-day coefficient of variation for all BZDs at all concentrations in the range of 0.45-7.69 % was calculated. The procedure can provide a simple, sensitive and fast method for the screening of six BZDs in adulterated soft drinks in forensic analysis.