Determination of trace amounts of gold in acid-attacked environmental samples by atomic absorption spectrometry with electrothermal atomization after preconcentration

Abstract

A method for determination of trace amounts of gold in environmental samples (rocks, soils, sediments, and waters) by atomic absorption spectrometry with electrothermal atomization (ETAAS) after preconcentration using a chelating sorbent Spheron Thiol 1000 is described. The method accurately determines gold between 0.001 and several tens of grams per ton in samples having complex variations in mineralogy. Pulverized samples are roasted at 650 degrees C to oxidize any sulfide and/or carbonaceous material. Samples are then subjected to a series of acid treatments to eliminate any silica matrix and to dissolve the sample. The Spheron Thiol 1000 is added to the sample solution, and then with sorbed gold is filtered out, washed, and ignited at 550 degrees C. The residue is dissolved in aqua regia, evaporated, dissolved in distilled water, transferred to a volumetric flask, and analyzed by ETAAS. The limits of detection of gold, based on the 3 sigma definition, were 0.5 ng g(-1) for 10-g samples (rocks, sediments, soils) and 0.05 ng mL(-1) for 1-L water samples. Precision of determination expressed by the relative standard deviation varied from 2.9% to 16.4%. The accuracy of the method is verified by analysis of certified reference materials. The obtained analytical results are in good agreement with attested values. The developed method was applied for gold determination in environmental samples affected by the acidification (acid mine drainage which is mainly a product of pyrite oxidation) from an open quartzite mine in the Sobov region situated NE of the city of Banská Stiavnica (Slovakia).

Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores

“…NOTE: Control cubic geometry (preferentially gyroidal Ia3d symmetry) and micrometric particle surfaces of mesoporous monolithic scaffolds by using triblock copolymer Pluronic P123 [P123; poly(ethylene oxide-block-propylene oxide-block-ethylene oxide) (EO 20 [10][11][12][13][14][15][16][17][18][19][20] min to obtain the optical gel-like wagon-wheel-shaped monolith around the wall of the connect flask [37][38][39] . 4.…”

“…Moreover, the recent surge in commodity prices has generated a new interest in the mining of e-wastes . This urban mine holds immense amounts of these metals (by comparison, Au and Pd are present in extremely low concentrations in rocks (~4 ng/g), soils (1 ng/g), seawater (0.05 µg/L), and river water (0.2 µg/L) [14][15][16] ). To ensure a continuing and reliable supply of palladium, gold and cobalt metals for future technological innovations and new electronic equipment, it is important to develop an efficient and low-cost technology for recycling precious metals from e-waste.…”

“…Several powerful and well-established methodologies and analytical techniques have been used to discriminate and quantify Au(III), Pd(II), and Co(II) in natural ore and industrial waste, including flame and carbon furnace atomic absorption spectrophotometry, ultraviolet-visible (UVvis) spectrophotometry, neutron activation analysis, and inductively coupled plasma mass spectrometry [14][15][16][21][22][23][24][25][26][27] . Despite their versatility and growing popularity, these analytical techniques suffer from many shortcomings.…”

Preconcentration of gold ions from water samples by modified organo-nanoclay sorbent prior to flame atomic absorption spectrometry determination

“…Gold belongs to the group of elements that occur on the earth in very low natural content. The concentration of Au in natural water is extremely low and its concentration is about 4 ng g −1 in basic rocks and 1 ng g −1 in soils [12]. The concentration of gold in environmental, geological and metallurgical materials is usually too low to be determined directly by atomic absorption spectroscopy owing to insufficient sensitivity and matrix interferences.…”

Ion Pair-Dispersive Liquid-Liquid Microextraction Coupled to Microsample Injection System-Flame Atomic Absorption Spectrometry For Determination of Gold at Trace Level in Real Samples

“…The concentration of gold in environmental samples is extremely in low level, as 0.05 ng mL -1 , 0.2 ng mL -1 and 1 ng g -1 have been reported for seawater, river water and soil samples, respectively. 2 Thus an accurate, sensitive and selective analytical method is required for gold determination. A wide variety of analytical techniques such as flame atomic absorption spectrometry (FAAS), 3,4 electrothermal atomic absorption spectrometry (ETAAS), 5,6 inductively coupled plasma atomic emission spectrometry (ICP-AES) 7,8 and spectrophotometry 9,10 to determine gold have been explained.…”