浊点萃取——火焰原子吸收光谱法测定面粉中痕量铬

以1,3-二(4-硝基苯氨基重氮)苯(BNPADB)为络合剂,利用非离子表面活性剂TritonX-114对痕量铬进行浊点萃取富集后用火焰原子吸收光谱法测定铬的含量。探究了溶液的pH、络合剂用量、表面活性剂用量、缓冲溶液、平衡温度等实验条件的影响。在优化条件下测定铬的检出限为5.9 ng/mL,富集倍数为18倍(10 mL溶液)。将该方法用于面粉中痕量铬的测定,得到了满意的结果。

Determination of Trace Amouts of Chromium in Flour Samples by Flame Atomic Absorption Spectrometry after Cloud Point Extraction

A new cloud point extraction-flame atomic absorption spectrometric(CPE-FAAS) method has been developed for the determination of trace Chromium.1,3-bis(4-nitrophenylamino-diazo) benzene(BNPADB) was selected as the complexing agent and TritonX-114 as the surfactant.The effect of experimental conditions such as pH,the concentration of complexing agent,the concentration of surfactant,pH concentration,equilibration temperature on the extraction recovery were discussed,and these conditions were optimized gradually.The test for the interferential ions that probably exist was conducted,under the optimal conditions,the detection limit of Chromium was 5.9 ng/mL,the enrichment factor was 18 for Chromium(10 mL).The method was used for determination of trace amounts chromium in flour samples,and satisfactory results were obtained.