Rapid spectrofluorimetric determination of plasma salicylate with edta and terbium

A rapid single-reagent spectrofluorimetric assay for salicylate in human blood plasma is reported. The method is based on ternary complex formation with terbium and EDTA in alkaline solution; it requires only 10 μl of plasma, and protein precipitation is not necessary. Within-assay relative standard deviations were better than 2.5%, and correlation with the Trinder method was excellent. The procedure is particularly suited for emergency use in cases of suspected aspirin poisoning.