固相萃取-火焰原子吸收光谱法分析水溶肥料铬形态

Speciation analysis of water-soluble fertilizer chromium by ion exchange separation and flame atomic absorption spectrometry

研究了采用阴离子交换柱吸附Cr^(6+),使之与Cr^(3+)分离,火焰原子吸收光谱法测定水溶肥料中水溶态Cr^(3+)及总铬含量,差减法测得Cr^(6+)含量。分析了仪器工作条件、试液上柱流速等对实验结果的影响。结果表明,在最优实验条件下,水溶态总铬测定值的相对标准偏差(RSD)为1.12%~3.13%,水溶态Cr^(3+)测定值的RSD为1.93%~2.93%;Cr^(3+)的加标回收率为98.8%~104.0%,Cr^(6+)吸附率为97.0%~102.0%,固相萃取-火焰原子吸收光谱法可用于水溶肥料中铬形态的检测,且具有成本相对较低、操作简便、重现性好等优点。

The adsorption of Cr6+on Cr3+was carried out by anion exchange column.The contents of Cr3+and total chromium in water-soluble fertilizer were determined by flame atomic absorption spectrometry.The content of Cr6+was determined by subtraction method.The effects of the working conditions of the instrument and the flow rate of the test solution through the column on the experimental results were analyzed.The results show that under the optimal experimental conditions,the relative standard deviation(RSD)of water-soluble total chromium measured value is 1.12%~3.13%,and the RSD of water-soluble Cr3+measured value is 1.93%~2.93%;the recoveries of Cr3+are between 98.8%and 104.0%,and the adsorption rate of Cr6+is between 97.0%and 102.0%.Solid Phase Extraction-Flame Atomic Absorption Spectrometry can be applied to the speciation analysis of chromium in water-soluble fertilizers,and has the advantages of relatively low cost,easy operation and good reproducibility.