Quantitative Analysis Of X-ray Fluorescence Without Standard Samples

X-ray fluorescence spectrometry (XRF) method is a kind of instrument analysis which belongsto chemical element analysis method. The sample will emit the characteristic X-ray fluorescence(secondary X-ray) which is related to the element the sample contains when there is a X-ray beamform the X-ray tube inspired on it. By analyzing the wavelength and intensity of the secondaryX-ray we can respectively get the information of qualitative and quantitative analysis. At present,X-ray fluorescence spectrum analysis is one of method in the material chemistry element analysiswith fastest development, most extensive and commonly use.Plenty of factors will affect the accuracy of quantitative analysis of XRF, but the matrix effectcomposed by absorption effect and enhanced effect is the mainly one. When detecting the sampledirectly the result of quantitative analysis will be affected by the matrix effect more or less. To getthe accurate result the further complicated correction which can be divided into mathematical andexperimental correction must be done.In this thesis, a brief introduction of development history, influence factors, research status andbasic principle of XRF analysis was presented. A spectral data processing software whose mainlyfunction were spectral calibration, determination the own ship of spectral peak, multi-peakresolution and peak intensity calculation was developed under the MFC VC6.0platform to simplifyexperimental data processing. Besides, we proposed an new method by making the unknownsample into thin film spectrum with proper thickness to overcome the matrix effect, to improve theresult of XRF quantitative analysis we considered the bremsstrahlung of the X-ray from the X-raytube and the absorption curve of the element to correct it further. On this basis, three groups ofblock samples and a group of thin films were prepared to test the new method. The block sampleswere respectively stainless steel, fifty-cent coin and CdTe target material. The thin films depositedin the PLD system were made from the CdTe target material. After detecting the block samples,we found that the mole ratio of elements of the sample detected by XRF without considering thebremsstrahlung was far from the accuracy while it became better when considering thebremsstrahlung. We got the result which was very close to the accuracy in the finally when wemade the block sample into thin one further to overcome the matrix effect. This proved that ournew method was feasible. The key to the new method was to choose the right method (such as:PLD) which could keep thin film sample the same components with the original sample. Theadvantage of our new method was obviously: we could get the accurate result of XRF quantitative analysis without the complex matrix correction, besides the complex preparation of sample and thepollution of sample in this course could also be avoided, the most important one was theimprovement of accuracy of XRF. The detection efficiency of XRF was also improved because ofthe fast sample preparation.