镉离子选择性电极法测定食品中的镉含量

Determination of Cadmium Content in Food with Cadmium Ion Selective Electrode

采用镉离子选择性电极法,建立快速测定食品中镉含量的方法。以干法灰化处理不同的食品样品,并在pH 5.0条件下,加入TISAB溶液,用镉离子选择性电极与饱和甘汞电极组成的化学电池测量试样的电位值,并采用标准曲线法推算出原食品中的镉含量。结果表明,土豆、海带和稻谷中的镉含量分别为0.154, 0.553和0.114mg·kg-1。该方法的加标回收率为97.55%~99.58%,相对标准偏差为0.68%~1.52%,准确度和精确度均较好,适用于食品中镉含量的快速检测。

The cadmium ion selective electrode method was used to establish a rapid detection method of cadmium in food.The different food samples were treated by the dry ashing method,and TISAB solution was added at pH of 5.0.The potential value of the sample was measured with a chemical cell consisting of a cadmium ion selective electrode and a saturated calomel electrode,and the standard curve method was used to calculate the cadmium content of the original food.The experimental results measured the content of cadmium in potatoes,kelp and paddy was 0.154,0.553 and 0.114 mg·kg-1.The recovery rate of the method was 97.55%-99.58%,the relative standard deviation of the method was 0.68%-1.52%,and this method had good accuracy,and was suitable for the rapid detection of cadmium in foods.