Direct detection of acetaminophen in urine by liquid chromatography with electrochemical detection using dual electrodes. Preliminary application to a single-dose pharmacokinetic study

A method for the direct determination of acetaminophen in urine based on liquid chromatography with series dual-electrode detection has been developed. No sample pretreatment steps are required except for filtration. The method gives a linear range from 0.5 to 300 μg ml^?1 and a detection limit of 0.2 μg ml^?1 (10 μl). The analysis time of the assay is less than 7 min. The pharmacokinetics of acetaminophen in urine from a subject who had orally ingested 450 mg (table form) of the drug were studied and various pharmacokinetic parameters were determined.