端视ICP-AES法测定茶叶中铅铜砷镉铬钴

AXIAL-VIEW ICP-AES DETERMINATION OF Pb Cu As Cd Cr AND Co IN TEA

研究了用ICP-AES法同时测定茶叶中6种重金属元素铅、铜、砷(为类金属元素)、镉、铬、钴的分析方法。方法回收率都在90%～104%之间,相对标准偏差在0.1%～8.3%之间,对茶叶标准物的测定值与推荐值基本一致,方法简便、准确,结果满意。

Optimum conditions of simultaneous determination of Pb Cu As Cd Cr and Co in tea by ICP-AES were studied. Working parameters of the instrument were described in detail. It was shown that the results obtained by digestion of samples with micro-wave heating were better in accuracy and precision than by the dry-ashing method. The suitable acidity of the sample solution was found to be in the range 0.22mol·L^(-1) to 1.76mol·L^(-1) of HNO_3. RSD's (n=5) obtained were in the range 0.1%～8.3%, and recoveries were in the range 90%～104%, for all these elements. The proposed method has been used in the analysis of CRM (GBW07605—GSV—4) giving results consistent with the certified values.