Ultrasound-assisted emulsification microextraction of oxazepam,alprazolam and diazepam from urine samples followed by quantification with HPLC analysis

The applicability of the (usaeme) method was evaluated by the extraction and determination of alprazolam,oxazepam and diazepam from urine samples. ultrasound-assisted emulsification microextraction (usaeme) based on applying a low density organic solvent was developed for the simultaneous determination of alprazolam,oxazepam and diazepam. toluene (35.0 μl) was injected slowly into a home-designed centrifuge glass vial containing a sample that was located inside the ultrasonic water bath. the resulting emulsion was centrifuged. the separated phase (about 20 μl) was completely transferred to another test tube with conical bottom using 50 μl hplc syringe and after evaporation,the residue was dissolved in 20 μl hplc grade methanol and injected into the separation system. under the optimum conditions,the enrichment factor 302,311 and 386 was obtained for oxazepam,alprazolam and diazepam from urine samples,respectively. the calibration graphs were linear in the range of 1.0-500 μg l -1 for diazepam,2.0-500 μg l -1 for oxazepam and alprazolam. detection limits were 0.6,0.6 and 0.2 μg l -1 for oxazepam,alprazolam and diazepam respectively in urine samples.