[Rapid Determination of Cu and Zn in PM2.5 with Wavelength Dispersive X-Ray Fluorescence Spectrometry].

This paper proposes the analyzing method of adopting wavelength dispersive X-ray fluorescence spectrometry to measure the content of Cu and Zn in PM2.5. PTFE membrane is used to prepare standard samples and atmospheric particulate samples; a research into sample cup’s structure，using polypropylene film of 6.7 μm to help to improved sample cup to package atmospheric particulate samples. The improved sample cup is used to measure the content of Cu and Zn in atmospheric particulate, which can obviously reduce background, improve peak/background ratio and decrease detection limit to target element; discussion is made on the measurement condition of Cu and Zn in PM2.5: taking Kα line as analysis line of Cu and Zn, selecting PX10 as analyzer crystal, using 300 μm pitch collimator, adopting scintillation detector for the Kα of Zn, applying the integrating of flow-gas proportional counter and closed-end proportional counter to the Kα of Cu, setting 50 kV, 50 mA as operating voltage and current. The prepared Cu and Zn standard sample is used to set up working curve, the results show that their linear correlations are better, accuracy are higher, relative standard deviations of Cu and Zn are 2.43% and 2.00%(n=8), detection limit are 0.028 and 0.021 μg·cm-2respectively, and analysis of the single sample only need 60 s. To sum up, this method can quickly and accurately analyze the content of Cu and Zn in PM2.5, and provide scientific basis for study the element content characteristics and source apportionment.