An HPLC method for the determination of salicylic acid, phenacetin and paracetamol in serum, with indications; two case-reports of intoxication

Abstract

Acetylsalicylic acid, paracetamol and phenacetin are the most frequently used non-narcotic analgesics in The Netherlands. Two new case reports, an intoxication by salicylate ointment and a paracetamol overdose, are described.

Indications and methods for the determination of these compounds are discussed. We describe a newHplc method for the simultaneous determination of salicylic acid, paracetamol and phenacetin in serum. Some other analgesics, like aminophenazone, phenazone and dipyrone can be determined by this method at the same time, 100Μl of serum is mixed with 600Μl methanol, centrifuged and an aliquot is injected into theRP-5C18Hplc column. A methanol—buffer pH=3.0 (40 + 50) mixture is used as mobile phase. Salicylamide can be used as internal standard. Coefficients of variation of 3.4% for salicylic acid, 1.9% for paracetamol and 3.4% for phenacetin are found and recoveries from calf's serum are 98–101% (n=10 per drug at 50 mg/l serum).

In neonatology the sample volume can be decreased from 100Μl to 10Μl. This method has proved to be reliable and suitable in clinical pharmacy and toxicology.