Highly sensitive spectrofluorimetric determination of trace amounts of lead with new fluorescent reagent 3-methoxy-4-hydroxybenzaldene-hydrazinecarbothioamide

A new fluorescent reagent, 3-methoxy-4-hydroxybenzaldene-hydrazinecarbothioamide (MHHTA), was synthesized. The fluorescent reaction of this reagent with lead was also studided.Based on this, a highly sensitive spectrofluorimetric method was developed for determination of trace amounts of lead at pH 9.6. Under optimal conditions, the Pb-MHHTA complex had excitation and emission peaks at 368 and 450 nm, respectively. The liner range of the method was from 3.0 to 45.0 μg/L with a detection limit of 0.72 μg/L for lead. Interference of other ions was studided. The method was successfully applied to the determination of lead in pig liver and wheat flour samples.