Assay of bromhexine in human plasma by capillary gas--liquid chromatography with nitrogen-selective detection and selected ion monitoring.

A specific, sensitive method for the determination of bromhexine in human plasma is described. It comprises a selective extraction procedure and a specific determination with capillary gas--liquid chromatography and nitrogen-selective flame ionization detection. The detection limit of the assay is about 0.5 ng/ml. The specificity of the assay was checked by gas chromatography--mass spectrometry. The method is applied to the pharmacokinetics of bromhexine in humans.