[A sensitive, specific colorimetric method for determining paracetamol in human plasma (author's transl)].

A sensitive and specific colorimetric assay for paracetamol (acetaminophen) in plasma is described. After a selective column extraction (Extrelut) and hydrolysis, paracetamol is determined by the (modified) Axelrod and Brodie procedure. The whole processing is performed in a centrifuge tube. This method yields a high recovery (90%), saves time and only 1 ml of plasma is needed. Due to low blank values, the limit of detection is as low as 0.2 microgram/ml. At a concentration of 10 and 2 microgram/ml the coefficient of variation is 4% and 10%, respectively. In contrast to the often used extraction method, no emulsions are formed with this column procedure. One person is able to perform 50 analysis per day.