Analysis of benzodiazepines and tricyclic antidepressants in serum using a common solid-phase clean-up and a common mobile phase.
A single, rapid and specific solid-phase clean-up procedure was developed for the analysis of benzodiazepines and tricyclic antidepressants using a carefully selected wash step and specific sequential elution. Benzodiazepines were eluted from the solid-phase column using as mixture of water-methanol-acetonitrile (2:3:3) followed by the elution of tricyclic antidepressants with methanol containing 0.6% diethylamine. A 30% solution of acetonitrile in phosphate buffer containing dimethyloctylamine was used as a common isocratic mobile phase for the analysis of benzodiazepines and tricyclic antidepressants on a reversed-phase column and detection was carried out at 242 nm. The sensitivity limit of the assay for benzodiazepines and tricyclic antidepressants was 25 ng/ml in serum with recoveries of 95-105% for benzodiazepines and 76-95% for tricyclic antidepressants. The results were linear for benzodiazepines over the range 50-2000 ng/ml and for tricyclic antidepressants over the range 25-500 ng/ml. Analysis for benzodiazepines and tricyclic antidepressants gave good precision, with a coefficient of variation of less than 5.0%. The method described here will be suitable for use in a clinical setting, where there is a concomitant use of benzodiazepines and tricyclic antidepressants.
Mazhar
M
M
Clinical HPLC Group, Bio-Rad Laboratories, Clinical Division, Hercules, CA 94547.
Binder
S R
SR
D014151:Anti-Anxiety Agents / Q000097:blood*; D000929:Antidepressive Agents, Tricyclic / Q000097:blood*; D001569:Benzodiazepines; D002851:Chromatography, High Pressure Liquid; D006801:Humans; D013056:Spectrophotometry, Ultraviolet
D014151:Anti-Anxiety Agents; D000929:Antidepressive Agents, Tricyclic; D001569:Benzodiazepines