全自动通氮蒸馏-自动电位滴定法测定酱腌菜制品中二氧化硫残留量不确定度评定  

Evaluation of Uncertainty in the Determination of Residual Sulfur Dioxide in Pickled Vegetable Products Using Fully Automatic Nitrogen Distillation Automatic Potentiometric Titration Method

作　　者：王丹丹 冯云[1] 周玮[1] 张晓强[1] WANG Dandan;FENG Yun;ZHOU Wei;ZHANG Xiaoqiang(Jiangsu Product Quality Testing&Inspection Institute,Nanjing 210007,China)

机构地区：[1]江苏省产品质量监督检验研究院,江苏南京210007

出　　处：《食品安全导刊》2023年第34期65-68,共4页China Food Safety Magazine

基　　金：江苏省市场监督管理局2020年度科技计划项目(KJ207548)。

摘　　要：目的:采用全自动通氮蒸馏-自动电位滴定法测定水果制品中的二氧化硫残留量,并对测定结果的不确定度进行分析及评定。方法:试样酸化后在充氮蒸馏条件下释放二氧化硫,用碳酸钠溶液吸收,用碘标准溶液作为滴定液进行全自动电位滴定,根据滴定体积计算二氧化硫含量。通过建立数学模型,分析检测过程引入的不确定来源和数值,计算各影响因素的不确定度分量并得出不确定度报告。结果:在95%置信区间下,扩展不确定度为0.000916 g·kg^(-1),酱腌菜中二氧化硫残留量测定结果为(0.276±0.000916)g·kg^(-1)(k=2,置信区间p=95%)。结论:影响测定结果准确性的主要因素为碘标准滴定溶液的浓度和样品测量重复性,在实验中应加以关注,确保检验结果的可信度。Objective:To determine the residual sulfur dioxide in fruit products by automatic nitrogen distillation and automatic potentiometric titration,and to analyze and evaluate the uncertainty of the results.Method:After acidification,the sulfur dioxide was released under the condition of nitrogen-filled distillation and absorbed with sodium carbonate solution.The iodine standard solution was used as titration solution for automatic potentiometric titration,and the sulfur dioxide content was calculated according to the titration volume.By establishing a mathematical model,the source and value of uncertainty introduced in the detection process are analyzed,the uncertainty components of each influencing factor are calculated and the uncertainty report is obtained.Result:Under 95%confidence interval,the extended uncertainty was 0.000916 g·kg^(-1),and the determination result of sulfur dioxide residue in pickled vegetables could be reported as(0.276±0.000916)g·kg^(-1)(k=2,confidence interval p=95%).Conclusion:The main factors affecting the accuracy of the test results are the concentration of iodine standard titration solution and the repeatability of sample measurement,which should be paid attention to in the experiment to ensure the reliability of the test results.

关 键 词：全自动通氮蒸馏-自动电位滴定法 二氧化硫 不确定度 酱腌菜 

分 类 号：O657.1[理学—分析化学] TS255.7[理学—化学]