Separation of Gold, Palladium and Platinum from Metallurgical Samples Using an Amberlite XAD-7 Resin Column Prior to Their Atomic Absorption Spectrometric Determinations

Abstract

It has been known for long time that gold, palladium and platinum are present in most ores, alloys and concentrates at very low values. The detection limits of an atomic absorption spectrometer are not low enough for their direct determinations in sample solutions. The determination of gold, palladium and platinum is also difficult because of the large concentrations of unwanted metals and/or salts, such as sodium, iron, nickel and copper. To minimize such problems, the analysis must incorporate preconcentration and separation steps to free these precious metals from the matrix components. In addition, high concentrations of matrix constituents, including the acids used for sample dissolution or digestion, may cause inaccuracies in a method, which is based on external calibration with dilute aqueous standards. For this purpose, several preconcentration and separation procedures for gold, palladium and platinum, such as solvent extraction, 1-3 coprecipitation, 4,5 ion-exchange 6-8 and adsorption, 9-11 have been suggested. Among these procedures, by far, the most popular procedure for analyte concentration and separation is solid-phase extraction. In general, the analyte from a relatively large volume of solution is selectively retained by a solid-phase material based on a variety of mechanisms, and then released into a relatively small volume of eluent. In solid-phase extraction procedures based on adsorption, complexes, chelates and ion associates, the analytes are retained on columns filled with XAD resins, 12,13 polyurethane foams, 14 activated carbon 15-17 and silica gel 18,19 etc. Amberlite XAD series in most studies in our working group have been successfully used. [20][21][22][23][24] The great tendency of gold, palladium and platinum to form very stable complex makes it possible to use inorganic complexing agents and extraction for their preconcentration. After sample decomposition, gold, palladium and platinum usually come in the form of stable halogeno complexes. For this reason, numerous procedures based on the use of halogeno complexes have been proposed for the preconcentration and separation of gold, palladium and platinum. 7,25,26 In this paper, a procedure is described for the determination of gold, palladium and platinum at trace levels in various metallurgic materials, such as pure copper and anodic slime, by applying complexation with halogenide and solid-phase extraction with an Amberlite XAD-7 resin column in combination with atomic absorption spectrometry. Experimental InstrumentA Perkin-Elmer Model 3110 atomic absorption spectrometer equipped with an air-acetylene burner was used for the determination of gold, palladium and platinum. The instrumental parameters were those recommended by the manufacturer. A pH meter (Nel pH-900 Model with a glasselectrode) was employed for measuring the pH values in the aqueous phase. Reagents and standard solutionsAll reagents were of analytical grade unless otherwise specified. Double-distilled water was used throughout the experiments. Extrapure hydrochlo...

Estimation of platinum in environmental water samples with solid phase extraction technique using inductively coupled plasma mass spectrometry

“…Solid phase extraction has been demonstrated to be a highly effective preconcentration method when first applied to spectrometric determination [14,19,20]. Among the different sorbents that were tested for this enrichment stage are resins such as polyacrylacylaminothiourea [21], imidazoline [22], Metalfix-Chelamine [23,24], Amberlite XAD-16 [25], Amberlite XAD-7 [26], Dowex 1-X10 [27], Polyorgs 17 [28], HHY-10A macropore anion resin [29], activated alumina [30] and modified silica gels like silica gel functionalized with 1,5-bis(di-2-pyridyl)methylene thiocarbohydrazide [31], modified silicagel SeparonTM SGX [32], silica gel modified with propylamine groups [33]. Very good sorption properties of this last resin led us to choose it for the present study.…”

Removal of nickel(II) and palladium(II) from surface waters

“…The analytical performance is not significantly different from those achieved by other methods described in the literature. The detection limits of investigated elements are superior to those of some preconcentration/separation methods [9,29,[44][45][46][47][48][49][50]. The sorption capacities are also better or comparable with the other methods.…”

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.…”