茜素紫褪色分光光度法测定食品中溴酸钾的含量

Study on Spectrophotometric Determination of Potassium Bromate by Oxidation-Decoloration of AlizarinViolet

研究了在盐酸介质中,溴酸钾氧化茜素紫的适宜反应条件,建立了新的测定痕量溴酸钾的分光光度法.结果表明:褪色溶液最大吸收波长为460nm,表观摩尔吸收系数为1.9×104L.mol-1.cm-1,溴酸钾在1mg.L-1～20mg.L-1范围内符合比尔定律,加标回收率为95%～103%,相对标准偏差为2.4%,检出限为1.02mg.L-1.该法用于食品中溴酸钾含量的测定,结果满意.

Using the oxidation-decoloration of alizarin violet by potassium bromate in hydrochloric acid medium, the appropriate conditions were studied and a new method for the determination of the trace potassium hromate was established.The experimental resuits showed that the maximum absorption peak is located at 460 nm with an apparent molar absorption coefficient of 1.9 ×10^4L. mol-1. cm-1. The linear range is 1-20mg.L-1 ,the recovery was from 95% to 103% ,relative standard deviation was 2.3% ;detection limit was 1.02 mg. L-1. The proposed method has been applied in determining of trace potassium bromate in food sample with satisfactory results.