流动注射褪色光度法测定食品中的亚硫酸盐

Determination of sulfite in foodstuffs by flow injection discoloration spectrophotometry

基于亚硫酸盐在碱性条件下与碱性品红的褪色反应，建立了流动注射光度分析测定食品中亚硫酸盐的新方法。在38样／h采样频率下检出限为0．016μg/mL，SO3^2-质量浓度在0．04～1．5μg/mL范围符合朗伯比耳定律，测定1．2μg/mL SO3^2- 11次，相对标准偏差为0．41％。该法可用于食品中亚硫酸盐的测定。

A new method for the determination of sulfite in foodstuffs by flow injection analysis is described, which is based on the discoloration of basic fuchsine in an alkaline medium. The calibration graph is linear in range of 0.04 1.5μg/mL SO3^2- . A detection limit of 0.016μg/mL is achieved at a sampling frequency of 38/h. The relative standard deviation is 0.41% for the determination of 1.2μg/mL SO3^2- （n = 11）. The proposed method has been applied to the analyses of several foodstuffs with satisfactory results.