等电位间隔电位滴定法测定葡萄酒中游离二氧化硫

Determination of free sulfur dioxide in wine by the equal potential interval potentiometric titration

目的:建立等电位间隔电位滴定法测定葡萄酒中游离SO2的方法。方法:采用间接碘量滴定,以等电位间隔法识别滴定终点。结果:方法 RSD≤0.5%,游离二氧化硫回收率在94.50%～103.7%,与自动电位滴定法比较,相对误差小于1.0%。结论:间接碘量法无需碘标准溶液,等电位间隔电位滴定法识别滴定终点准确可靠,重现性好,适合葡萄酒中游离二氧化硫含量的测定。

Objective： To establish a method for determination of free sulfur dioxide in wine by the equal potential interval potentiometrie titration. Methods： According to indirect iodimetry, the end - point of titration could be judged with the equal potential interval potentiometrie titration. Results： The RSD was 0.3 % -0.5 %, the recovery rate for free sulfur dioxide was 94.50% - 103.7%. Compared with automatic potentiometric titration, the relative deviation for free sulfur dioxide was less than 1.0%. Conclusion ： The indirect iodimetry is simple, accurate without iodine standard solution. The equal potential interval potentiometric titration is accurate, reliable with good repeatability. It is suitable for determination of free sulfur dioxid in wine.