A fast and accurate microwave-assisted digestion method for arsenic determination in complex mining residues by flame atomic absorption spectrometry.
A fast and accurate microwave-assisted digestion method for arsenic determination by flame atomic absorption spectrometry (FAAS) in typical, complex residues from gold mining is presented. Three digestion methods were evaluated: an open vessel digestion using a mixture of HCl:HNO(3):HF acids (Method A) and two microwave digestion methods using a mixture of HCl:H(2)O(2):HNO(3) in high (Method B) and medium-pressure (Method C) vessels. The matrix effect was also investigated. Arsenic concentration from external and standard addition calibration curves (at a 95% confidence level) were statistically equal (p-value=0.122) using microwave digestion in high-pressure vessel. The results from the open vessel digestion were statistically different (p-value=0.007) whereas in the microwave digestion in medium-pressure vessel (Method C) the dissolution of the samples was incomplete.
Dept of Metallurgical and Materials Engineering, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Fernando L
FL
Pantuzzo
Julio César J
JC
Silva
Virginia S T
VS
Ciminelli
D001151:Arsenic / Q000032:analysis*; D008872:Microwaves; D008906:Mining; D013054:Spectrophotometry, Atomic / Q000379:methods*
D001151:Arsenic