摘要
采用氟离子选择电极法测定砖茶中氟含量,探讨不同金属掩蔽剂对测试效果的影响。结果表明,以柠檬钠+浓盐酸作金属掩蔽剂,测定的电位值与氟浓度的对数呈直线关系(y=-59.17x+248.1,R^2=0.999),方法最低检出限为0.022 mg/L。其精密度与准确度较好,8次重复测定的RSD为0.51%,3个不同浓度样品的加标回收率为94.64%~105.88%,平均回收率为99.10%。测试产区砖茶样品氟含量为603.9~1 246.5 mg/kg,销区砖茶氟含量在836.4~1 011.8 mg/kg之间,二者差异不显著。
Selective fluoride electrode method was used to determine fluoride content in brick tea and the influence of different masking reagents to the test results was discussed. The results showed that, when sodium citrate and HCI were used as masking reagent, there existed a line relationship between electric potential value and logarithm of fluoride content （y= -59.17x＋248.1, R^2=0.999）, and the detection limit of the method was 0.022 mg/L. The precision and accuracy were superior to other masking reagents, RSD=0.51%, the recovery range of 3 different concentrations of samples was 94.64%-105.88%, the average recovery rate was 99.10%. The fluorine in brick tea was tested, that was 603.9-1 246.5 mg/kg in origin area and 836.4-1 011.8 mg/kg in sales territory, and there was no significant difference between them.
出处
《食品工业》
CAS
北大核心
2016年第11期173-176,共4页
The Food Industry
基金
四川省教育厅科技基金(15ZB-0496)
宜宾市科技基金(2014NY-019)
关键词
金属掩蔽剂
氟离子选择电极法
氟
砖茶
测定
masking reagent
selective fluoride electrode method
fluorine
brick tea
determination
