碱消解-火焰原子吸收光谱法测定土壤中六价铬

建立了碱消解-火焰原子吸收光谱法测定土壤中六价铬的方法.讨论了pH值对六价铬测定的影响.干扰实验的结果表明同等含量的三价铬对六价铬测定无干扰.实验对比了无背景校正、氘灯背景校正、塞曼背景校正三种工作方式,分别对低、中、高三个水平土壤六价铬标准物质进行了测定,结果表明,低含量的土壤样品用塞曼背景校正方式测定的结果更准确,...

Determination of hexavalent chromium in soil by alkali digestion flame atomic absorption spectrometry

A method for the determination of hexavalent chromium in soil by alkali digestion - flame atomic absorption spectrometry (FAAS)was developed. The results of interference experiment show that there is no interference between trivalent chromium and hexvalent chromium. The experiment compared the three working modes of no background correction, deuterium lamp background correction and Zeeman background correction, Three soil reference materials were measured, among which hexavalent chromium content was divided into low content, medium content and high content,The results show that, low content soil samples were measured more accurately using the Zeeman background correction method, finally, the working mode of Zeeman background correction is chosen. The linear range of the method was 0.1~2.0mg/L, the correlation coefficient R is 0.9998; the relative standard deviation is 1.74%, when the sampling mass is 5 g and the volume is 100 mL, the detection limit of the method is 0.20 mg/kg, the recovery rate was 84.8%~86.9%.