Determination of potassium bromate in bread and kamaboko by photometric ion chromatography.

Abstract
Photometric ion chromatography is a novel method by using the photometer as a detector. A feature of this method is the use of light absorbing ion in the mobil phase, and the appearance of transparent sample ion in the effluent is detected by "trough"in the base line absorbance. We applied this technique by using a conventional HPLC system equipped with a commercially available ion exchange separation column to the determination of bromate in such foodstuffs as bread and kamaboko. Sample solution was prepared by aqueous extraction and mixed with acetone for removal of proteins. After evaporation of the organic solvent, the aqueous solution was dechlorinated by a DOWEX column (Ag-form), and then was subjected to chromatography. Samples of bread and kamaboko were spiked with 5.4 ppm and 8.4 ppm of bromate, respectively, and examined by the above method. The average recoveries were 88.3% in bread and 82.9% in kamaboko, and the coefficients of variation were 7.7% and 7.9%, respectively. The detection limit was 1 ppm. The above findings indicate that bromate can be detected by HPLC using conventional instrumentation, and the sensitivity of this system is comparable to conductimetric detection