A simple microanalytical technique for the determination of paracetamol and its main metabolites in blood spots

The use of blood spot collection cards is a simple way to obtain specimens for analysis of drugs with a narrow therapeutic window. We describe the development and validation of a microanalytical technique for the determination of paracetamol and its glucuronide and sulphate metabolites from blood spots. The method is based on reversed phase high-performance liquid chromatography with ultraviolet detection. The limit of detection of the method is 600 pg on column for paracetamol. Intra- and inter-day precision of the determination of paracetamol was 7.1 and 3.2% respectively. The small volume of blood required (20 mul), combined with the simplicity of the analytical technique makes this a useful procedure for monitoring paracetamol concentrations. The method was applied to the analysis of blood spots taken from neonates being treated with paracetamol. (C) 2002 Elsevier Science B.V. All rights reserved.