石墨炉测定土壤中镉的升温程序优化研究

Research on the Temperature Programming Optimizationof Measurement of Cadmium(Cd)in Soil by Graphite Furnace

采用硝酸钯作为基体改进剂,进行了微波消解-石墨炉原子吸收光谱法测定土壤中镉的方法研究。通过研究灰化温度、原子化温度对镉元素吸光度的影响,优化了石墨炉加热程序。研究表明:选择盐酸-硝酸-氢氟酸体系以及程序升温微波消解方式,能够对土壤样品进行较好的消解。针对测试体系及仪器,灰化温度设定为650℃、原子化温度设定为1 850℃,能够获得较好的吸光度测试结果。测试条件下,镉元素方法检出限为0.11ng/mL、精密度为2.12%。采用微波消解-石墨炉原子吸收光谱法测定土壤中镉的方法具有准确、快捷、灵敏度高的优点。

In this paper,the measurement of Cadmium(Cd)in soil by microwave digestion-graphite furnace atomic absorption spectrometry while using Pd(NO3)2as matrix modifier was studied.According to the effect of ashing temperature and atomization temperature on the absorbance of Cd,the heating procedure of microwave digestion was optimized.The research showed that the soil sample could be digested by using the acid system(HCl-HNO3-HF)and temperature programmed microwave digestion.The ashing temperature was set at 650℃,and the atomization temperature was set at 1 850℃.Under this condition,the detection limit of Cd was 0.11ng/mL,and the RSD was 2.12%.The measurement of Cadmium in soil by microwave digestion-graphite furnace atomic absorption spectrometry is approved as a method with the advantages of accuracy,celerity and high sensitivity.