Spectrofluorometric determination of zinc with 1,5-bis(2,3-dihydroxyphenylmethylene) thiocarbohydrazone

Abstract

1,5-Bis(2,3-dihydroxyphenylmethylene)thiocarbohydrazone was synthesized; its ionization constants are reported. A procedure is described for the spectrofluorimetric determination of 5–540 ng ml−1 zinc in 60/40 (v/v) ethanol/water medium, acetate-buffered to apparent pH 6.5 (λex=400 nm, λem=508 nm). Interferences were evaluated and the procedure was applied with good results to the determination of zinc in potable waters (0.3–3 μg ml−1) and lubricating oils.