title: Evaluation of Field Portable X-Ray Fluorescence Performance for the Analysis of Ni in Soil.
abstract: As a rapid, in-situ analysis method, Field portable X-ray fluorescence spectrometry (FP-XRF) can be widely applied in soil heavy metals analysis field. Whereas, some factors may affect FP-XRF performance and restrict the application. Studies have proved that FP-XRF has poorer performance when the concentration of target element is low, and soil moisture and particle size will affect FP-XRF performance. But few studies have been conducted in depth. This study took an example of Ni, demonstrated the relationship between Ni concentration and FP-XRF performance on accuracy and precision, and gave a critical value. Effects of soil moisture and particle size on accuracy and precision also had been compared. Results show that, FP-XRF performance is related to Ni concentration and the critical value is 400 mg x kg(-1). Relative standard deviation (RSD) and relative uncertainty decrease while the Ni concentration is below 400 mg x kg(-1), hence FP-XRF performance improves with increasing Ni concentration in this range; RSD and relative uncertainty change little while the Ni concentration is above 400 mg x kg(-1), hence FP-XRF performance does not have correlation with Ni concentration any more. For in-situ analysis, the relative uncertainty contributed by soil moisture is 3.77%, and the relative certainty contributed by particle size is 0.56%. Effect of soil moisture is evidently more serious than particle size both on accuracy and precision.
authors.forename: Guo-dong
authors.initials: GD
authors.lastname: Du
authors.forename: Mei
authors.initials: M
authors.lastname: Lei
authors.forename: Guang-dong
authors.initials: GD
authors.lastname: Zhou
authors.forename: Tong-bin
authors.initials: TB
authors.lastname: Chen
authors.forename: Rong-liang
authors.initials: RL
authors.lastname: Qiu