Comparative Study on Two Pretreatment Processes for Chemical Phase Analysis of Gold in Geological Samples by Atomic Absorption Spectrometry

Abstract

Sample pretreatment is important for chemical phase analysis of elements. In this study, the geological samples of the Laozuoshan gold mine are chosen to pretreat by ultrasonic centrifugation and cyclotron oscillation, and the content of gold in eight chemical phases (water-soluble, ion exchange and clay adsorption, organic matter bound, iron-manganese oxide bound, naked or seminaked, carbonate bound, sulfide bound, and insoluble silicate states) is determined by atomic absorption spectrometry. The results show that the gold content of water-soluble, ion exchange and clay adsorption, iron-manganese oxide, and naked or seminaked states in the rock and ore samples is low, and some samples have high gold content of insoluble silicate states in the two methods. However, the gold content of organic matter bound, carbonate bound, and sulfide bound states obtained by ultrasonic centrifugation and cyclotron oscillation methods is significantly different. According to the X-ray fluorescence spectrometry data and the actual geological condition, the result given by the cyclotron oscillation method is more reasonable. The gold content of sulfide bound state in sediment samples is the highest and consistent with the mineral information, which could be applied to preliminarily predict the rock and ore conditions in the corresponding mining areas. In contrast with ultrasonic centrifugation, the cyclotron oscillation method has the advantages of simplicity, high efficiency, practicality, and environmental protection, and it can be better used for the determination of gold chemical phase state in geological samples by atomic absorption spectrometry.

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“…Mineral Composition: Calcium, iron, phosphorus, magnesium, sodium, potassium, and zinc were estimated by atomic absorption spectrophotometry (Thermo-Scientific ICE 3000) 9 . Dried tuber powder was precisely weighed (2g each) followed by wet digestion with HNO 3 : HClO 4 (2:1) in a conical flask for 2-3 h. 10 ml of HCl was added.…”

A new desorption method of polyurethane foam for the determination of gold and a comparative study on four desorption methods based on meta-analysis

“…The conical ask was then placed on the cyclotron oscillator for 30 minutes. 10,11 The PUF was taken out, the residue was washed and squeezed for later use.…”

“…The treatment methods before gold determination include dry ashing, [2][3][4] and wet acid digestion. Enrichment, such as precipitation, 5 ion exchange resin, 6 solvent extraction, [7][8][9] PUF adsorption, 10,11 extraction chromatography, 12 is followed. There are many testing methods for gold, including atomic absorption spectrometry, 13 inductively coupled plasma mass spectrometry 14,15 and so on.…”

Gold determination in soil by ICP-MS: comparison of sample pretreatment methods

“…Until now, the widely used Au test methods include titration (Stefano et al 2015), atomic absorption spectrometry (Yilmaz and Soylak 2014;Choi et al 2017;Zhou et al 2017;Tang et al 2019), inductively coupled plasma optical emission spectroscopy (George and Konstantinos 2016;Hassan et al 2016;Xue et al 2016), microwave plasma atomic emission spectrometry (Balaram et al 2013), and inductively coupled plasma mass spectrometry (ICP-MS) (Liu et al 2013;Tao et al 2017;Satyanarayanan et al 2018;Chen et al 2019). Among them, ICP-MS meets the test conditions of most geological samples and has the advantages of low detection limit, high sensitivity, and wide linear range (Qi et al 2011;Resano et al 2012;Yim et al 2012;Strnad et al 2016;Berezhnaya and Dubinin 2017).…”