Development of a Liquid Chromatographic Method for the Simultaneous Determination of Six Benzodiazepines in Human Plasma After Solid-Phase Extraction

Abstract

A simple and fast procedure is presented for the simultaneous determination of alprazolam, bromazepam, diazepam, lorazepam, lormetazepam, and tetrazepam in human plasma. The drugs were isolated by solid-phase extraction, and the subsequent analysis was carried out by high-performance liquid chromatography coupled with a diode-array detector (HPLC-DAD). This allowed recoveries of around 90% to be obtained with good sensitivity, selectivity, and resolution of the eluting peaks. The detector response at 230 nm was linear within the benzodiazepine concentration range of 20–4000 ng/mL in human plasma, with values of less than 6.7% and 5.4% for precision and accuracy, respectively.

Keywords:

• Benzodiazepines
• HPLC-DAD
• Plasma
• Solid-phase extraction

Notes

^a Low levels, 120 ng/mL.

^b High levels, 2000 ng/mL.

^a Low levels, 120 ng/mL.

^b High levels, 2000 ng/mL.