A novel method for iodate determination using cadmium sulfide quantum dots as fluorescence probes.

We have developed a novel method for the determination of iodate based on the carboxymethyl cellulose-capped CdS quantum dots (QDs). Factors affecting the iodate detection were investigated, and the optimum conditions were determined. Under the optimum conditions, the relative fluorescence intensity of CdS quantum dots was linearly proportional to IO(3)(-) over a concentration range from 1.0 × 10(-8) to 1.0 × 10(-5) mol L(-1) with a correlation coefficient of 0.9987 and a detection limit of 6.0 nmol L(-1). Iodide, being oxidized by bromine to form iodate, was detected indirectly. The method was successfully applied to the determination of iodate and total amount of iodine in table salt samples. The related mechanism was also discussed.