13. Effects of Important Factors on Determination of Metals in Soil Samples Using Hand-Held X-ray Fluorescence

The influence of the releasion, migration and transformation of heavy metals in the process of mineral mining on the content of soil components near the mine needs to be studied, and some reliable element determination methods need to be adopted in the research process. Soil samples in 20 mesh (0.850 mm), 40 mesh (0.425 mm), 80 mesh (0.180 mm) and 100 mesh (0.150 mm) from farmland and mining areas of Longnan City in Gansu Province were determined by S1 Titan hand-held X-ray Fluorescence (XRF) spectrometer for understanding factors affecting composition contents determination. Results showed that mesh of samples sieved had a definite impact on determination of heavy metals. Repeatability was greatly affected when samples were in 20 mesh and 100 mesh. Contents of As and Al₂O₃ in samples were easily affected by mesh of sample. It should be concerned that As contents of some soil samples from farmland in Longnan City of Gansu Province were more than 30 mg/kg, contents of metals, sucn as Pb, Zn and As from mining area in Longnan City of Gansu Province were more than 1000 mg/kg. The phenomenon revealed by these measurement data required attention.