Rapid determination of procainamide and its N-acetyl derivative in human plasma by high-pressure liquid chromatography.

A rapid, specific, high-pressure liquid chromatographic method for the determination of procainamide and its N-acetyl derivative in plasma was developed. The procedure is fast enough (15 min from receipt of blood to reporting value) to be used for emergency determinations. The sensitivity, precision, and accuracy are sufficient for routine monitoring of therapeutic levels in patients. The assay is specific enough to be valid in the presence of a number of drugs and dietary substances present in clinical samples.