Determination of Trace Elements in Some Arsenic Minerals by Atomic Emission Spectrometry With Inductively Coupled Plasma After Matrix Removal

摘要

Various trace elements content in two arsenic minerals were investigated using atomic emission spectrometry with inductively coupled plasma (ICP-AES). Both, realgar (As4S4) and orpiment (As2S3) belonged to the sulfide group of minerals. The studied minerals originate from Allchar mine, Crven Dol locality, Republic of Macedonia. To avoid the interference of arsenic as matrix element, a liquid-liquid extraction of its iodide complex into toluene in hydrochloric solution was applied. The extraction method was optimized. Operating parameters, such as the amount of As present and number of extractions were determined. The removal of arsenic was performed by KI with 4 steps of extraction with toluene for 5 min shaking time each, was higher than 99%. After the phase separation, determination of different trace elements in the aqueous phase was undertaken. The proposed procedure was verified by the method of standard additions and by its applications to the minerals. The results of the trace elements determination shown that satisfactory recoveries were obtained.