Paracetamol (acetaminophen) analysis by high performance liquid chromatography: interference studies and comparison with an enzymatic procedure.

A simple, robust, high performance liquid chromatographic method for serum paracetamol determination in both the therapeutic and overdose concentration ranges is described. The within- and between-batch precision of the method was better than CV 5% at both micromolar and millimolar concentrations, and recovery of added paracetamol from drug-free serum exceeded 96%. No interference from any of the other drugs, drug metabolites, and dietary constituents tested was found. Performance data in the overdose concentration range has been compared with that from the enzymatic kit procedure, and results from the two assays showed good correlation (r = 0.97).