DETERMINATION OF 5 BENZODIAZEPINES IN AQUEOUS-SOLUTION AND BIOLOGICAL-FLUIDS USING SOLID-PHASE MICROEXTRACTION WITH CARBOWAX(TM) DVB FIBER COATING/

A method using direct solid-phase microextraction (SPME) coupled with gas chromatography (GC) and GC/mass spectrometry (GC/MS) for the deter mination of five benzodiazepines (diazepam, nordiazepam, oxazepam, tem azepam, and lorazepam) in aqueous solution, urine, and serum was devel oped. The Carbowax(TM)-divinylbenzene (CAX/DVB) coated fiber extracted all five benzodiazepines in the highest amounts compared to the other fiber coatings examined: poly(arcylate) (PA), 100 mu m poly(dimethyls iloxane) (PDMS), and poly(dimethylsiloxane)/divinylbenzene (PD MS/DVB) . The highest amount of all five and benzodiazepines extracted was und er conditions of saturated salt with pH 7 and sampling at 45 degrees C with agitation. The method was linear over the range of 0.1-2 mu g/mL of sample using the CAX/DVB coated fiber. The limits of detection wer e determined as 0.02 mu g/L, 0.03 mu g/mL, and 0.1 mu g/mL of sample f or diazepam and nordiazepam, oxazepam and lorazepam, and temazepam. Th e standard deviation values of intraday and interday measured for the five benzodiazepines were all less than 12.5%. The new method was also applied to the analysis of the above target analytes in urine and ser um. (C) 1998 John Wiley & Sons, Inc.