罗丹明6G比色法同时测定污染蔬菜中的铅和镉

Rapid Determination of Lead and Cadmium in Pollute Vegetable by Rhodamine 6G Colorimetry

摘要:

硝酸（1+11）浸提干燥蔬菜样品，利用罗丹明6G直接水相比色同时测量样品中的Pb、Cd。实验确定了Pb在0.1~1.0 μg/mL、Cd在0.01~0.1 μg/mL浓度范围内符合线性相关关系，显色体系最佳pH=5.0。硝酸浸提法检测了六种蔬菜样品，与湿消解法相比Pb、Cd平均提取率分别为97.47%、96.82%；平均RSD<5；平均加标回收率为102.6%、101.2%，结果令人满意。

Abstract:

Dry vegetable was extracted by nitric acid (1+11) and the content of lead and cadmium in sample could be simultaneously got by rhodamine 6G aqueous phase colorimetric test. The results confirmed that lead and cadmium had good linear relation in concentration range of 0.1~1.0 μg/mL and 0.01~0.1 μg/mL, respectively. The best pH value for the colorimetric system is 5.0. Compared with wet extraction, the average extraction efficiency of nitric acid for lead and cadmium were 97.47% and 96.82%, and average RSD was less than 5. Average recoveries of standard addition in six samples were 102.6% and 101.2%.