冰片糖二氧化硫残留量测定的不确定度评定

Evaluation of Uncertainty in the Determination of Residual Sulfur Dioxide in Golden Slab Sugar

根据GB 5009.34-2022《食品安全国家标准食品中二氧化硫的测定》的要求,采用通氮蒸馏-酸碱滴定法测定冰片糖试样中二氧化硫残留量,评估测定过程中不确定度来源。结果表明:冰片糖试样中二氧化硫残留量为(23.4±0.5)mg/kg(k=2,置信水平为95%)。通过不确定度评定得出在冰片糖试样二氧化硫残留量测定过程中不确定度主要来源于实际耗用氢氧化钠标准滴定液体积,其次为样品重复性测量。

According to the requirements of GB 5009.34-2022“National Food Safety Standard for the Determination of Sulfur Dioxide in Food”,the nitrogen distillation acid-base titration method was used to determine the residual sulfur dioxide in the sample of golden slab sugar,and to evaluate the source of uncertainty in the determination process.The results showed that the residual sulfur dioxide in the golden slab sugar sample was(23.4±0.5)mg/kg(k=2,confidence level 95%).Through uncertainty evaluation,it was found that the uncertainty in the determination of sulfur dioxide residue in golden slab sugar sample mainly comes from the actual volume of sodium hydroxide standard titration solution consumed,followed by sample repeatability measurement.