Trace Element Analysis of Solutions at the PPB Level

Abstract

We have developed a technique to determine the dissolved solid components of water and other liquids by Energy- Dispersive X-Ray Fluorescence (EDXRF) spectrometry. The liquid samples are presented to the spectrometer as small dried spots of the residue remaining after evaporation of the liquid. The dried residues are mounted on thin plastic films cemented to 35 mm plastic slide mounts. Elements from sodium through uranium are detected with detection limits less than one nanogram in favorable cases. Precision of the measurement is better than 2 % relative in favorable cases for secondary-target excitation, and is typically 5 to 10 % for direct excitation given the geometry of the instrument. Detection limits are as low as a part per billion relative to the original liquid for solutions whose total dissolved solid content is 1000 part per million or less.

Micro X-ray fluorescence in materials characterization

“…This application is not imaging based, however it highlights the capability of trace analysis using spatially resolved MXRF. The dried spot methodology was first published over 10 years ago by Meltzer and King (1991). Since that time a number of publications have demonstrated the utility of this method for trace analysis of aqueous solutions as described in Colletti and Havrilla (1997).…”

Preconcentration of environmental waters by agar for XRF analysis

“…However, in the case of environmental water, the XRF method is not widely used, because the sensitivity of the usual XRF spectrometer except for the SR-XRF or TXRF is lower than ICP-AES and AAS due to the influence of the matrix effect. Therefore, XRF method for the analysis of the environmental water generally requires the preconcentration of the analytes through the sample pretreatments, such as dried spot method [1,2] ion exchange [3], and precipitation by the chelating agent [4,5]. The dried spotted method is a rapid and simple method for correcting the trace metals in aqueous solutions on flat substrate or filter paper.…”

Optimization of a dried residue specimen preparation method for quantifying analytes in plutonium metal using WDXRF

“…Thus, the potential exists for radioactive solution to leak inside the instrument. The casting of solutions into dry residues for XRF analysis has been investigated by others for preconcentrating trace elements to improve the detection limits [3][4][5][6]. A similar dried residue technique was developed here to eliminate the need to analyze radioactive solutions [2,[7][8][9].…”