DETERMINATION OF ZINC BY FLOW-INJECTION WITH FLUOROMETRIC DETECTION IN A MICELLAR MEDIUM

A room-temperature flow injection spectrofluorimetric method is presen ted for the determination of Zn(II), based on the use of salicylaldehy de thiocarbohydrazone in the presence of Triton X-100 and sodium aceta te-acetic acid buffer. Various physical and chemical variables affecti ng the reaction in the flow system were evaluated. The proposed method is very selective. The calibration graph is linear over the range 10- 1000 ng/ml, with a detection limit of 5 ng/ml and a relative standard deviation at the 50 ng/ml level of 1.8 %. The method was successfully applied to the determination of Zn(II) in drinking waters and biologic al samples.