Determination of precious metals in geological samples by continuous powder introduction microwave induced plasma atomic emission spectrometry after preconcentration on activated carbon

Trends in Sorption Preconcentration Combined with Noble Metal Determination

“…[23][24][25] Dry ashing followed by dissolution of the residue with acids is often used for the digestion of biological, environmental and clinical samples. [26][27][28] Acid dissolution is extensively used for the digestion of different matrices, and can be carried out in open or closed systems, such as high-pressure ashers (HPA) [29][30][31] or high-pressure vessels heated by microwaves. [32][33][34][35] Microwave techniques are especially effective for the dissolution of samples with a high content of organic matter, for example, carbonaceous shales, biological materials, pharmaceuticals and others.…”

“…For example, the sorbents after preconcentration are decomposed by dry ashing in a muffle furnace (400 -600˚C), and then the residues are dissolved with acids. 26,28,[133][134][135] The sorbent can be decomposed by wet ashing under boiling with a mixture of acids (HNO3, HClO4, H2SO4), and in some cases with the addition of H2O2. 136 The microwave decomposition of sorbents with acids in open and closed vessels has also been proposed.…”

“…28 Examples of noble metal determination in different kinds of materials by ICP-AES after sorption preconcentration are given in Table 2 and in original papers. 24,25,28,43,67,83,89,128,129,137,138,152,153 3·3 Inductively coupled plasma mass spectrometry Inductively coupled plasma mass spectrometry (ICP-MS) is one of the most promising methods for the determination of noble metal traces due to its low detection limits, efficiency, and multielement determination, as well as its unique capability to measure element isotopic ratios. 154,155 The popularity of ICP-MS is rapidly growing thanks to the development of a market for commercial equipment and considerable price cutting.…”

Development of sensitive determination method for platinum in geological materials by carbon slurry sampling graphite furnace atomic absorption spectrometry

“…The determination of trace levels of platinum in geological materials requires the application of very sensitive analytical techniques, such as graphite furnace atomic absorption spectrometry (GFAAS) [3][4][5][6][7][8][9][10], inductively coupled plasma atomic emission spectrometry (ICPOES) [3][4][5]9,11], inductively coupled plasma-mass spectrometry (ICPMS), neutron activation analysis (NAA) or adsorptive voltammetry (AdV) [3][4][5]. It is worth mentioning that platinum occurs in geological materials at low concentrations and its distribution is nonhomogeneous [1].…”

Application of Carbon Sorbents for the Concentration and Separation of Metal Ions

“…22,[24][25][26][27][28][29][30][31][32][33][34][35][36][37] Sorptive capacity and selectivity of these carbon sorbents vary for different metal ions. Higher valency metal ions are usually preferred and metal sorptive selectivity of carbons differs even within a series of metal ions with the same charge.…”