[Microanalysis of plasma isoniazid and acetylisoniazid by high performance liquid chromatography]

A method for the analysis of isoniazid and acetylisoniazid in plasma or serum has been developed. This report describes a simple, quick and economically optimized reversed-phase high-performance liquid chromatographic assay using a small sample size without solvent extraction step. Isoniazid was condensed with cinnamic aldehyde after trichloroacetic acid deproteinisation. The method correlated well with a fluorimetric procedure. Precision, sensibility and accuracy were good. Common antituberculous drugs did not interfere.