离子色谱法测定茶叶中4种阴离子

The Determination of 4 Kinds of Anion Content in the Tea by Ion Chromatography

为考察茶叶中F^-、Cl^-、NO3^-、SO4^2-这4种离子含量,称取0.5000 g固体茶叶,高温灰化。采用IC6000型离子色谱,以流速0.7 mL/min的3.6 mmol/L碳酸钠溶液为淋洗液进行洗脱,外标法对茶叶中4种阴离子进行定量分析。结果表明,方法回归方程的线性相关系数在0.9990~0.9996之间,4种阴离子检出限为0.5~1.5 mg/kg,加标量约为本底浓度的0.5,1.0和1.5倍,加标回收率在95.0%~104.5%之间,测定值的相对标准偏差(n=3)为0.97%~1.35%。方法具有操作简便、检测干扰小、结果准确可靠的优点。

To determine the content ofF^-、Cl^-、NO3^-、SO4^2-in the tea,the IC6000 ion chromatography was used for the 0.5000 g solid tea of high temperature ashing.The elution procedure was 3.6 mmol/L sodium carbonate solution and the flow rate as 0.7 mL/min.A external method was used for determination of 4 kinds of inorganic anion.The results showed the correlation coefficients of linear regression equations were 0.9990-0.9996.The method of detection limit was 0.5-1.5 mg/kg for 4 kinds of inorganic anion.The standard addition concentration was about background concentration of 0.5,1.0 and 1.5.The recoveries were 95.0%-104.5%with relative standard deviation(n=3)of 0.97%-1.35%.It was indicated that the advantages of present method had simple operation,high sensitivity and good repeatability.