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Yu J.,Hubei Geology Research Laboratory
Asian Journal of Chemistry | Year: 2012

The conditions of separation and enrichment for Au, Pt and Pd in geological samples were studied by 717 anion exchange resin. The exchange method was conducted under the optimized adsorption conditions (pH = 3.0). The effects of different enrich methods and different exchange procedures were compared. The present procedures are relatively simple and can be applied with high precision and reproducibility to the analysis of geological samples with wide ranges of concentrations. Finally, the application of our methods was verified by the analysis of geology reference materials.

Li D.,Hubei Geology Research Laboratory | Wang D.,Hubei Geology Research Laboratory | Li B.,Hubei Geology Research Laboratory
Yejin Fenxi/Metallurgical Analysis | Year: 2011

The adsorption property and separation conditions of 717 anion exchange resin to trace gold, platinum and palladium in geological samples were studied. The sample was dissolved with HCl + aqua regia under heating in water bath. Only Mo in dissolved elements had interference with the determination of Pd, which could be eliminated using mathematical formula correction. When the flow rate of eluent was 2 mL/min, the enrichment effects of gold, platinum and palladium in 5% HCl medium reached its best, and the recoveries were close to 100%. After correcting the influence of coexisting ions, the national first-class certified reference materials were determined by inductively coupled plasma mass spectrometry, and the difference between determination results and certified values was satisfactory. The detection limit of method were 0.6 ng/mL, 0.5 ng/mL and 0.7 ng/mL for Pd, Pt and Au, respectively. Five random geological samples were analyzed by this method in comparison with NiS fire assay-ICP-MS method. The determination results were consistent. The results of two methods were checked by double sample's variance F test, and there was no significant difference.

Li D.,Hubei Geology Research Laboratory | Zhao Z.,Hubei Geology Research Laboratory | Chu Q.,Hubei Geology Research Laboratory | Fang J.,Hubei Geology Research Laboratory
Bulletin of the Korean Chemical Society | Year: 2011

A rapid and inexpensive method was developed for the determination of trace silver in geological samples by using sulfhydryl cotton coupled with ICP-MS. The interferences such as 90Zr, 92Mo and 93Nb on silver were investigated in detail. Sulfhydryl cotton was found to be an effective adsorbent for separation of interferences for Ag in the solutions. Excellent agreements with the certified values were obtained for all the certified reference materials. The memory effects of Ag by ICP-MS were examined by using different agents, including water, nitric acid, and HCl-thiourea to all standards/samples. The agents also acted as cleansing solutions. A combination of HCl with thiourea gave the minimum memory effect. For comparison of results, a proposed Chinese Geology Survey procedure DC-ARC-AES and a direct determination pretreatment method of ICP-MS (water bath- auqa regia digestion) were studied. Under optimal conditions, the detection limits of our method for 107Ag and 109Ag were 1.2 ng/g and 1.3 ng/g, which offered much better accuracy for some difficult analysis geological samples such as GBW07604, GBW07605.

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