摘要
A new fluorescent reagent 2,4-dihydroxyacetophenone benzoylhydrazone (DHAPBH) was synthesized and its ionization constants were established spectrophotometrically. The fluorescent reaction of this reagent with cadmium was studied. The cadmium ion can form a stable binary chelate with DHAPBH, having a mole ratio of 1 :2 in the pH range of 3.6-4.4. Based on this chelation reaction, a highly sensitive spectrofiuorimetric method was developed for determination of trace amounts of cadmium in a water-ethanol (7:3 in volume ratio) medium at pH = 4.0. Under these conditions, the Cd-DHAPBH complex has excitation and emission maxima at 306 and 437 nm, respectively. The linear range of the method is from 0.36 to 140μtg·L^-1 and the detection limit is 0.27 μtg·L^-1 of cadmium. Interferences of other ions were studied. The method was successfully applied to the determination of cadmium in mineral water, tap water, fiver water, and wastewater.
A new fluorescent reagent 2,4-dihydroxyacetophenone benzoylhydrazone (DHAPBH) was synthesized and its ionization constants were established spectrophotometrically. The fluorescent reaction of this reagent with cadmium was studied. The cadmium ion can form a stable binary chelate with DHAPBH, having a mole ratio of 1 :2 in the pH range of 3.6-4.4. Based on this chelation reaction, a highly sensitive spectrofiuorimetric method was developed for determination of trace amounts of cadmium in a water-ethanol (7:3 in volume ratio) medium at pH = 4.0. Under these conditions, the Cd-DHAPBH complex has excitation and emission maxima at 306 and 437 nm, respectively. The linear range of the method is from 0.36 to 140μtg·L^-1 and the detection limit is 0.27 μtg·L^-1 of cadmium. Interferences of other ions were studied. The method was successfully applied to the determination of cadmium in mineral water, tap water, fiver water, and wastewater.
基金
This work was financially supported by the Educational Commission of Gansu Province, China (No. 029-04)