凯氏定氮-电位滴定仪联合快速检测果脯中的二氧化硫

Determination of Sulfur Dioxide in Preserved Fruits Using Auto-Kjeldahl's Apparatus Combined with Automatic Potentiometric Titrator

采用FOSS2200型全自动凯氏定氮仪-Metrohm 809型自动电位滴定仪联合快速检测果脯中的二氧化硫,全过程只需6min,不仅操作简单,而且大大缩短了分析时间。经统计学检验,该法与国标中的玻璃蒸馏法测定的结果无显著性差异(P>0.05),相对偏差小于0.94%,加标回收率为90.39%～103.40%,样品最低检出限为2.6mg/kg,适合各种固、液体样品大批量的蒸馏检测。

A method using FOSS 2200 auto-Kjeldahl＇s apparatus coupled with Metrohm 809 automatic potentiometric titrator was developed to determine sulfur dioxide in preserved fruits.This method is simple,rapid and accurate and the whole process only needs 6 minutes.No significant difference （P〉 0.05） between determination results obtained using Kjeldahl＇s apparatus and glass distiller for distillation was observed.The relative error of this method was lower than 0.94%.Average spike recovery rates for sulfur dioxide in 5 preserved fruits were between 90.39% and 103.40%,and the detection limit was 2.6 mg/kg.Therefore,this method is most suitable for determining sulfur dioxide in solid and liquid food samples.