Quantification of salicylate in serum by use of salicylate hydroxylase

In this enzymatic method for salicylate in serum, Pseudomonas salicylate hydroxylase (EC 1.14.13.1) is used. This stable enzyme catalyzes the stoichiometric, unidirectional conversion of salicylate and NAD(P)H to catechol and NAD(P)+ in the presence of molecular oxygen. The concentration of salicylate in a clinical sample is determined by measuring the delta A at 340 nm as compared with a standard. This new method is rapid, highly specific, requires 40 microL or less of sample, and we saw no interference by any of 61 commonly used drugs. Lipemic, icteric, or hemolyzed samples can be used. Furthermore, this method does not involve extraction, deproteinization, or derivatization. Results are precise and agree well with those obtained by the Trinder test.