Determination of midazolam by high-performance liquid chromatography.

In a previous communication [l] we reported a procedure for the serum determination of midazolam using gas chromatography (GC) with a nitrogenselective detector. GC with nitrogen-selective detection resulted in a selective procedure for the direct determination of midaxolam with a sensitivity of 50 ng/ml. We present, in this paper, a procedure for the direct determination of midazolam and its major metabolite (1-hydroxymethylmidazolam) using high-performance liquid chromatography (HPLC) with ultraviolet (W) detection. The sensitivity of the assay is increased by the use of HPLC and better linearity was observed in the lower (ng/ml) concentration range.