红葡萄酒中二氧化硫残留量测定方法的改进研究

目的]改进测定葡萄酒中二氧化硫含量的直接碘量滴定法。方法]在测定前对红葡萄酒进行预处理,选用交联聚乙烯吡咯烷酮去除葡萄酒的颜色对滴定终点判断的干扰,再进行直接碘量法滴定,并对改进新方法的精密度和准确度进行检验以评价新方法的可行性和实用性。结果]交联聚乙烯吡咯烷酮对红葡萄酒有较明显的脱色效果,在较大程度上消除了葡萄酒的深红色对滴定终点的干扰,使滴定终点前后颜色变化明显,提高了终点判断的准确性。结论]该方法既弥补了直接碘量滴定法的不足,又可在葡萄酒中直接进行滴定测试,简便快捷、准确、重复性好。

Study on the Improved Determination Method of Sulfur Dioxide Residue in Red Wine

Objective] To improve the method of direct iodometric titration to determine the sulfur dioxide content in red wine.Method] The red wind was firstly pretreated by cross-linked polyvinyl pyrrolidone to remove the large interference of the wine color to judge the reaction end point,and then determined by the direct iodometric tritration,the precision and accuracy of the improved method were tested to evaluate the practicability of this method.Result] The cross-linked polyvinyl pyrrolidone had obvious decolorization effect,it greatly removed the interference of the deep wind color to the titration results,the method changed the color of wine,and improved the accuracy of the endpoint determination.Conclusion] The method supplements the shortcomings of the direct iodometric titration,but also can be directly used in the iodometric test of wind,it is rapid and accurate with good repeatability.