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Determination of Gold in e‐Waste Dust Samples and Geological Matrices by ICP ‐ MS after Extraction by an HC lO 4 ‐ HB r‐ HI ‐ Aqua Regia Mixture
Author(s) -
Strnad Ladislav,
Šebek Ondřej,
Fayadová Marie,
Vrba Jan
Publication year - 2016
Publication title -
geostandards and geoanalytical research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.037
H-Index - 73
eISSN - 1751-908X
pISSN - 1639-4488
DOI - 10.1111/j.1751-908x.2015.00368.x
Subject(s) - aqua regia , extraction (chemistry) , leaching (pedology) , chemistry , standard addition , analytical chemistry (journal) , sample preparation , chromatography , environmental chemistry , environmental science , detection limit , soil water , metal , soil science , organic chemistry
This study describes two methods (Procedures‐1 and ‐2) for the direct extraction of Au by an inorganic acid mixture ( HC lO 4 ‐ HB r‐ HI ‐ aqua regia ) from complex sample matrices. Standard PTFE jars at 200 °C were used to decompose test portions of 0.5–1 g, with subsequent precise and accurate analysis by ICP ‐ MS without any other preconcentration or separation. Procedure‐1 decomposed samples effectively without the necessity of leaching with HF and was developed for dust samples from e‐waste (electronic waste) processing; however, testing on geological reference materials showed very good results. The analyses of replicate decompositions ( n = 5) from both procedures yielded very good precision (< 5% RSD ) for most of the reference materials. The accuracy achieved was better than ± 10%, with the exception of NIST SRM 2782 data from Procedure‐1. Two unknown samples of dust from e‐waste processing (P‐1 and VM ‐1) exhibited elevated concentrations of Au (21.31–61.64 μg g −1 ) with precision better than 10% ( n = 5). The proposed techniques are simple, sensitive and sparing in the use of chemicals, and are designed for a variety of e‐waste dust samples. No significant influences were observed for the predicted spectral interferences on mass 197 Au.