食品中钠含量测定方法的比较分析

Comparative Analysis of Methods for Determining Sodium Content in Food

通过直接滴定法、火焰原子吸收光谱法和电感耦合等离子体质谱法3种方法分别测定30种不同类型预包装食品中的钠含量。结果表明,滴定法操作简单、耗时短、成本低、对环境污染小,但准确度低,对于本底含钠量高及除氯化钠之外的钠盐中的钠离子测定有较大的局限性。火焰法在钠含量0~6.0 mg/L范围内与吸光度呈良好线性关系,相关性为0.9937;以芒果混合汁做空白样,加标回收率为91.99%~111.10%。ICP-MS法在钠含量0~6.0 mg/L离子强度呈良好线性关系,相关性为0.9998;以芒果混合汁做空白样,加标回收率为96.10%~107.20%。火焰法和ICP-MS法准确度高、分析范围广、具有自动化高效的优势。

Direct titration(hereinafter referred to as titration method),flame atomic absorption spectrometry(hereinafter referred to as flame method)and inductively coupled plasma mass spectrometry(hereinafter referred to as ICP-MS method)were used to determine the sodium content of 30 different types of prepackaged foods.The results show that the titration method is simple to operate,time consuming,low in cost,low in environmental pollution,but low in accuracy.It has greater limitations for the determination of sodium ions with high background sodium content and sodium salts other than sodium chloride.The flame method has a good linear relationship with the absorbance in the range of sodium content of 0~6.0 mg/L,and the correlation is 0.9937.The recovery of standard addition with mango mixed juice as blank sample was 91.99%~111.10%.The ICP-MS method has a good linear relationship with the ionic strength in the range of sodium content of 0~6.0 mg/L,and the correlation is 0.9998.The recovery rate of standard addition with mango mixed juice as blank sample was 96.10%~107.20%.The flame method and ICP-MS method have high accuracy,wide analysis range,and have the advantages of automation and high efficiency.