Determination of fluorine and chlorine in standard steel residues and zinc sulfide concentrates by ion chromatography-matrix interference study

Abstract

1 Ion chromatographic based determination of F − and Cl − . 2 Investigation of the effect of matrix constituent elements on F − and Cl − recovery. 3 Digestion of steel residues and zinc sulfide concentrate standard samples. 4 Various parameters of alkali fusion were optimized. The sensitive determination of trace fluorine and chlorine contents in complex inorganic matrices such as steal residues and zinc sulfide concentrates is challenging cause difficulty in their digestion and presence of various matrix interferences species. Therefore, in this study, the effect of various constituent elements of geological samples including Ni, As, Ag, Pb, Hg, Co, SiO 2 , Bi, Sb, Cr, Zn, Cd, Ag, CaO, MgO, Al, Fe, KBr, and KI on the alkali-fused steam distillation-based recoveries of fluoride and chloride were investigated for better understanding the application of this method in various geological samples. Hence, a simple, cost-effective and modified alkali fusion-steam distillation-ion chromatography (SD-IC) method was developed for the sensitive and selective determination of halogens in standard steel resides and zinc sulfide concentrate samples. For optimum extraction of analytes various digestion parameters including alkali fusion amount, fusion temperature, and fusion time along with distillation volume were sequentially optimized. The developed method shows good linearity in the range 0.2 - 3.0 mg/kg with correlation coefficient (r) values greater than 0. 99991. The limit of detection for fluoride and chloride were appeared 0.07326 mg/kg and 0.02331 mg/kg, respectively with precision (repeatability and the intermediate precision) less than 4.12%. The results of standard steal residue and zinc sulfide concentrate samples were in good agreement (91.27- 100.18%) with their certified reference values (CRMs). SD-IC is a simple, cost-effective, and sensitive method for the determination of fluoride and chloride contents in complex geological samples (steal residues and zinc sulfide concentrates).