低温等离子体探针-原子荧光光谱法检测镉元素的方法研究

摘要

A new method for determination of cadmium on the surface of PVDF membrane by low temperature plasma probe-atomic fluorescence spectrometry (LTP-AFS) was developed.In this work,the Co was found to have fluorescence sensitization effect on Cd,the sensitization mechanism was also discussed.When the Co/Cd (mass ratio) was within 1 to 2,the sensitivity of Cd was increased about 8 times.The parameters such as discharge power,discharge gas flow rate,carrier gas flow rate,shield gas flow rate,observation height and sampling distance were optimized.Under the optimum experimental conditions,this method had a good linear correlation (R2≥ 0.991) within 0-100 ng,the detection limit of Cd was 0.127 ng.The accuracy of this method was verified by comparing the measurement results of LTP-AFS with ICP-MS.The method of direct determination dried PVDF membrane after added trace volume (≤ 2 μL) solution is particularly suitable for the analysis of small volume samples and field analysis.%建立了低温等离子体探针-原子荧光光谱法直接检测PVDF膜上Cd含量的方法.研究了固体中Co对Cd的荧光增敏作用,并讨论了其增敏机理.在Co/Cd(质量比)为1～2时,Cd的分析灵敏度提高了约8倍.本实验对放电功率、放电气流量、载气流量、屏蔽气流量、原子化器高度和采样距离等参数进行了优化,在最佳实验条件下,本方法在0～100 ng范围内线性相关性较好(R2≥0.991),方法检出限为0.127 ng.本方法对实际样品的测量结果与ICP-MS的测量结果相一致,表明本方法的准确度较高.PVDF膜上滴加微量体积(≤2μL)溶液样品风干后直接测定的方法,特别适合于微体积样品的分析及现场分析.