天青A-溴酸钾体系催化光度法测定微量甲醛

Determination of trace formaldehyde by catalytic spectrophotometry with azur A-KBrO_3

研究了在H2SO4介质中，微量甲醛对KBrO3氧化天青A有较强的催化作用，建立了催化光度法测定微量甲醛的新方法。方法的线性范围为0．035～O．66mg/L，检出限为0．016mg/L。该方法用于米粉、粉丝等食品中甲醛的测定，测定结果的相对标准偏差（RSD）小于5％，加标回收率为98．5％～101．2％。

A new catalytic spectrophotometric method for the detemtination of trace formaldehyde has been proposed. The method is based on the catalytic effect of trace formaldehyde on the reaction between potassium bromate and Azur A. The detection limit is 0.016 mg/L with linear range of 0.035 -0.66mg/L. The method has been applied to the determination of trace formaldehyde in rice flour and vermicelli. The RSD is less than 5 %. The recoveries are between 98.5% and 101.2%.