凯氏蒸馏-滴定法测定蔬菜干制品中的二氧化硫残留量

目的建立凯氏蒸馏-滴定法测定蔬菜干制品中二氧化硫残留量的方法。方法选取银耳、松茸、黄花菜、百合干4种蔬菜干制品,采用凯氏蒸馏与普通全玻璃蒸馏两种方法对二氧化硫残留量进行测定。进一步研究凯氏蒸馏-滴定法的检出限、精密度和加标回收率。并用SPSS数据统计软件对结果进行分析。结果 2种蒸馏方法测定结果无显著性差异,凯氏蒸馏法的检出限为0.0012g/kg,相对标准偏差为0.38%～0.72%,加标回收率为93.0%～94.5%。结论凯氏蒸馏法滴定法操作简单,耗时短,检出限低,精密度好,安全性高,可用于蔬菜干制品中二氧化硫残留的批量检验。

Determination of sulfur dioxide residue in dried vegetable products by Kjeldahl distillation-titration method

Objective To establish a method for determination of sulfur dioxide residue in dried vegetables by Kjeldahl distillation-titration. Methods The sulfur dioxide residue in 4 kinds of dried vegetables including tremella, matsutake, daylily and dried lily were determined by 2 methods of kjeldahl distillation and conventional all-glass distillation. The limit of detection, precision and recovery rates of Kjeldahl distillation-titration were further investigated. And the results were analyzed by SPSS software. Results The results of 2 methods had no significant difference. The limit of detection of Kjeldahl distillation-titration was 0.0012 g/kg, with the relative standard deviations of 0.38%~0.72% and recovery of 93.0%~94.5%, respectively. Conclusion The Kjeldahl distillation- titration is simple in operation, low in detection limit, high in precision and security, which is suitable for detecting the sulfur dioxide residue in dried vegetables.