ISSN:
0049-8246
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Physics
Notes:
A new method of sample preparation with a very high sample dilution range of about 1:70 is proposed for X-ray spectrometric determination of major elements in silicate rock samples. In spite of this large dilution, sensitivity is not sacrificed as the sample, uniformly distributed in an ion exchange resin (i.e. a light organic matrix), is presented for analysis in a small volume (thin film technique). The fusion product of the sample with lithium borate (40% of sample, 60% of flux) is dissolved by thorough mixing in an aqueous suspension of a strong acid cation exchange resin. During the cation exchange dissolution, the cations originally present in the rock sample are transferred quantitatively and homogeneously onto the resin. The dried resin is then sprinkled uniformly on a plastic adhesive strip in such a way that a single layer of resin beads (about 100 μm) is obtained. The impregnated strip is then analysed, with a counting time of 20 s for all elements except for Mg (100 s).The analysis of several geochemical standards for Al2O3, Fe2O3, MgO, CaO, TiO2 and K2O shows the practical absence of matrix effects. Furthermore, a working curve could be constructed for each element as a straight line between a high standard and a blank sample (0%), the latter consisting simply of pure dry cation exchange resin in H+ form. As only 90 to 100 mg amounts of resin beads are necessary for making a thin film (diameter 4 cm), microanalysis with 5 to 10 mg of mineral or rock samples also becomes possible.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/xrs.1300020204
