悬浮体进样-基体改进效应石墨炉原子吸收光谱法直接测定土壤中的铅和镉  

Direct Determination of Lead and Cadmium in Soil by Slurry-Sampling Graphite Furnace Atomic Absorption Spectrometry Using Matrix Modification Technique

作　　者：孙汉文[1] 温晓华[1] 梁淑轩[1] 

机构地区：[1]河北大学化学与环境科学学院

出　　处：《光谱学与光谱分析》2006年第5期950-954,共5页Spectroscopy and Spectral Analysis

基　　金：河北省自然科学基金(203110)资助项目

摘　　要：建立了以悬浮体进样-基体改进效应石墨炉原子吸收法测定污灌区土壤中痕量铅和镉的新方法.以琼脂为悬浮剂、NH4H2PO4作基体改进剂,研究了土壤悬浮液的稳定性和基体改进效应及干扰效应.基于原子化峰值时间的对数值与原子化温度之间的线性关系测得Cd和Pb的表观活化能,探讨了基体改进效应机理.应用标准曲线进行校准,Pb和Cd的检出限分别为9.05×10^-10g·mL^-1和1.76×10g·mL^-1-11g·mL^-1,Pb和Cd的回收率分别为91%～97%和93%～109%,相对标准偏差为4.2%～7.8%.以土壤标准品作参照,测得值与标准值相符.A method for the direct determination of lead and cadmium in soil by slurry-sampling graphite furnace-atomic absorption spectrometry using NH4 H2PO4 as matrix modifier was developed. The effects of slurry stability, particle size of sample, matrix modifiers, ashing temperature, atomization temperature and common coexistent components on the signal intensities of lead and cadmium were investigated. The apparent activation energies of lead and cadmium were measured based on the linear relationship between the logarithm value of atomization peak time and atomization temperature. The mechanism of matrix modification was discussed. Under optimized conditions, the detection limit was 9.05×10^-10g·mL^-1 for Pb and 1.76 ×10^-111g·mL^-1 for Cd. The recoveries were in the range of 91%-97% for Pb and 93%-109% for Cd. The relative standard deviations were in the range of 4. 2%-7.8%.

关 键 词：石墨炉原子吸收 悬浮进样 基体改进 表观活化能 土壤 铅 镉 

分 类 号：O657.3[理学—分析化学]