Study On Measurement Of Heavy Metals In Water By Energy Dispersive X Fluorescence Analysis

With the rapid development of modern industry and agriculture,environmental problems are becoming more and more serious and the status of heavy metal pollution in water is becoming more and more common.Mainly the spectrophotometry,atomic absorption spectrometry analysis of common methods of heavy metals in the water at present(AAS),inductively coupled plasma atomic emission spectrometry(ICP-AES),inductively coupled plasma mass spectrometry(ICP-MS),relative to other analysis methods,X ray fluorescence analysis method as a mature analysis method,has the advantages of simple operation,rapid analysis,suitable for field analysis,has incomparable advantages of other methods,but its application is more concentrated in the rock,alloy and other solid sample analysis field,how will the X ray fluorescence analysis method to expand the field of liquid samples,to achieve rapid and effective detection of heavy metals in water is also an important research topic.This paper combines the liquid solid phase enrichment method and X ray fluorescence thin sample analysis method,selection of high pure Na montmorillonite as solid adsorbent,systematic discusses the enrichment factors and the process of sample preparation,realizes the analysis of portable energy dispersive X ray fluorescence instrument for Pb in water,As,Cd and Cr.The results are as follows:(1)To investigate the feasibility of Na high purity montmorillonite liquid heavy metal enrichment,on the same conditions,adsorption time,solution temperature,solution p H,natural water main component of high pure Na enrichment effect of Pb,As,Cd,Cr,obtained the best reaction conditions of the enrichment efficiency.(2)The use of filtration enrichment thin sample preparation process of sample preparation analysis combined with energy dispersive X fluorescence spectrometer,the effect of montmorillonite on the quality of thin sample preparation are discussed,0.300 g was confirmed as the best quality;under the optimum conditions,the enrichment of heavy metal mixed with different concentrations of the standard solution,Pb,As,Cd,Cr standard thin samples the preparation,the concentration gradient of covering 0.01 to 1 mu g/m L;the optimal parameters of energy dispersive X fluorescence spectrometer is established,the Pb,As,Cd water,Cr analysis method,the spectrum overlap phenomenon of Pb and As in the mixed system,select the Pb L beta as the analysis line and reduce the influence of As on Pb analysis,compared the characteristic peak deduction method and binary linear regression for the correction effect of overlapping peaks,reduce the effect of Pb on the As analysis,the linear coefficient of the standard curve of each element is greater than 0.878.(3)To evaluate the accuracy and precision of the analytical method,when the theoretical concentration of the analyte elements is greater than 0.01 ?g/m L,it's accuracy is less than 26%,the precision of RSD(n=10)is less than 20%;the detection limit analysis method in Pb,As,Cd and Cr respectively for 7.64?g/L,2.65?g/L,16.2?g/L,8.01?g/L;application to verify the analysis method through the actual sample,when Pb,As,Cd,Cr and scalar is 0.5?g/m L,the recovery of elements in each sample at the rate of 70% to 120%,the sample preparation method basically to meet the analysis of heavy metals in water,is of great significance for the application of extended energy dispersive X fluorescence.