Spectrophotometric screening method for acetaminophen in serum and plasma
Liu, T.Z.; Oka, K.H.
Clinical Chemistry 26(1): 69-71
1980
ISSN/ISBN: 0009-9147 PMID: 7356576 Document Number: 165784
A simple, economical procedure for rapidly detecting acetaminophen, an analgesic antipyretic, in serum or plasma is described. The method is based on the reduction by the drug of ferric 2,4,6-tris(2-pyridyl)-s-triazine, at an acidic pH, to ferrous 2,4,6-tris(2-pyridyl)-S-triazine complex, which absorbs maximally at 593 nm. Absorbance and acetaminophen concentration are linearly related from 25-400 mg/l, and so therapeutic and toxic concentrations can be measured. The method is accurate; day-to-day CV for 2 pooled control specimens (103 and 227 mg/l) were 4.4 and 6.6%. Correlation studies, with an established nitration method and with the free-radical diphenylpicrylhydrazyl dye method, showed correlation coefficients of 0.985 and 0.915, respectively. Of 25 commonly used drugs tested, only levodopa, oxyphenylbutazone and phenylephrine interfere significantly. Interference from salicylate, salicylamide and phenylbutazone was insignificant.