Background: X-ray fluorescence (XRF) determination of elements in atmospheric PM2.5 has the advantages of being fast and nondestructive

but it is a complicated problem for the selection and preparation of standard sample. Purpose: The aim is to introduce a standard sample preparation of Pb element determination in PM2.5 by XRF which is a simple

cheap

accurate and reproducible method for preparing the sample. Methods: The thin sample was prepared with the help of drip Pb standard method

and the feasibility of the hydrophilic polytetrafluoroethylene (PTFE) membrane as a carrier material was discussed. The metal ions with PTFE of strong hydrophobicity and low adsorption were chosen as sample preparation slab. After the discussion on the relationship between droplet volume and the reproducibility of sample preparation

the best droplet volume for sample preparation reached 0.3 mL. The standard sample of Pb element analysis of PM2.5 was prepared by using above methods. Results: The working curve of Pb was established with the linear correlation 0.996

which was of good accuracy and precision. The detection limit was 35 ng?cm?2. Conclusion: Using the working curve

Pb content in the atmosphere in April

2015

in Chengdu city is analyzed. The results showed that the concentration range of Pb in PM2.5 was 0?526 ng?cm?3

and the average concentration of Pb in the nighttime was higher than that in the daytime. Abstract