Direct determination of zolpidem and its main metabolites in urine using capillary electrophoresis with laser-induced fluorescence detection.

Zolpidem is a new sleep inducer belonging to the imidazopyridine class. We wish to report a method for the determination of zolpidem and its main metabolites in urine without extraction using capillary electrophoresis with UV laser-induced fluorescence detection with a He-Cd laser. A 10-nl sample of urine can be directly applied to the capillary. The separation is carried out within 10 min, and the limit of detection is 2 ng/ml. This procedure is very simple and fast. No organic solvents are necessary.