Intelligent Simultaneous Quantitative Online Analysis of Environmental Trace Heavy Metals with Total-Reflection X-Ray Fluorescence

Abstract

Total-reflection X-ray fluorescence (TXRF) has achieved remarkable success with the advantages of simultaneous multi-element analysis capability, decreased background noise, no matrix effects, wide dynamic range, ease of operation, and potential of trace analysis. Simultaneous quantitative online analysis of trace heavy metals is urgently required by dynamic environmental monitoring and management, and TXRF has potential in this application domain. However, it calls for an online analysis scheme based on TXRF as well as a robust and rapid quantification method, which have not been well explored yet. Besides, spectral overlapping and background effects may lead to loss of accuracy or even faulty results during practical quantitative TXRF analysis. This paper proposes an intelligent, multi-element quantification method according to the established online TXRF analysis platform. In the intelligent quantification method, collected characteristic curves of all existing elements and a pre-estimated background curve in the whole spectrum scope are used to approximate the measured spectrum. A novel hybrid algorithm, PSO-RBFN-SA, is designed to solve the curve-fitting problem, with offline global optimization and fast online computing. Experimental results verify that simultaneous quantification of trace heavy metals, including Cr, Mn, Fe, Co, Ni, Cu and Zn, is realized on the online TXRF analysis platform, and both high measurement precision and computational efficiency are obtained.

Optimization scheme for rapid analysis of copper ore grade using EDXRF

“…For copper concentrates (17.81% to 29.18%), the average absolute error (∆ ̅ ) is 0.238%, the average relative error (ε ̅) is 1.01%, the maximum absolute error (Δ max ) is 0.508%, and the maximum relative error (ε max ) is 2.12%. For matte samples (25.65% to 52.22%), the average absolute error (∆ ̅ ) is 0.421%, the average relative error (ε ̅) is 1.01%, the maximum absolute error (Δ max ) is 0.888%, and the maximum relative error (ε max ) is 2.24% [10].…”

Distributed Water Pollution Source Localization with Mobile UV-Visible Spectrometer Probes in Wireless Sensor Networks

“…However, few efforts have been made to construct one synthesis analytical model of multiple parameters, considering the inherent features of continuous spectra. A scalable UV-visible spectral decomposition strategy is considered here, based on our former work on total-reflection X-ray fluorescence analysis [15]. As shown in Figure 5, the measured absorbance curve is decomposed into one background curve and a number of characteristic curves of possible components, which can be written as:$Ffalse(\lambda false)=f_{0}false(\lambda false)+true\sum _{i=1}^n{w}_i{f}_{i}false(\lambda false)\hspace{1em}\lambda \in [{\lambda }_{\min },{\lambda }_{\max }]$ where F is the measured absorbance curve, f 0 is the background curve, f i is the normalized characteristic curve of component i , and w i is the proportionality coefficient of component i .…”

“…This research focuses on the distributed water pollution source localization method in WSNs. Experience of spectral analysis and network deployment is gained in the former research [15]. However, new application scenarios of WSNs and the very purpose for water pollution source localization are particularly discussed here.…”

2016 Atomic Spectrometry Update – a review of advances in X-ray fluorescence spectrometry and its applications

“…A set of papers dealing with more fundamental questions is presented as follows. In an interesting paper by Ma et al 69 the remarkable success and the advantages of TXRF were mentioned, stating also that simultaneous quantitative on-line analysis of trace heavy elements is urgently required by dynamic environmental monitoring and management. The authors came to the conclusion that TXRF had the potential in this application domain, however it called for an on-line analysis scheme as well as a robust and rapid quantication method.…”