气体扩散耦合顺序注射光度分析法测定葡萄酒中的二氧化硫*

依据在微碱性条件下,亚硫酸根离子可与孔雀绿溶液发生加成反应并使其褪色的原理,建立了气体扩散耦合顺序注射分光光度法测定葡萄酒中二氧化硫的新方法。当接收液流速为1.2mL/min和4.2mL/min时,方法的线性响应范围分别为1.0-5.0μg/mL和5.0-50.0μg/mL,方法的检出限为0.33μg/mL,相对标准偏差（RSD）≤0.43%,对葡萄酒样中二氧化硫测定的加标回收率为98.7%-104.7%。

Determination of Sulfur Dioxide in Wine Samples by Spectrophotometry Coupled to Gas Diffusion Sequential Injection System

A SIA system combined with gas diffusion separation was developed for the determination of sulfur dioxide in wine samples based on addition reaction of sulfite ion and malachite green solution in weak alkaline medium.Under the optimum experimental conditions,the linear ranges were 1.0-5.0μg/mL and 5.0-50.0μg/mL when the flow rates were 1.2 mL/min and 4.2 mL/min in receptor medium,respectively.The detection limit（3σ）was 0.33μg/mL with the relative standard deviation（n=7）no more than 0.43%.The recovery was in the range of 98.7% -104.7%.The method was successfully applied to the determination of sulfur dioxide in wine samples.