Analysis of Arsenic in High Purity Metallic Copper by Hydride Generation-Atomic Absorption Spectrometry (HG-AAS)

Introduction

Copper minerals may contain a certain amount of arsenic components in some cases as a result of the mineral formation process. Although arsenic (As) removal treatment is conducted in the copper (Cu) refining process when necessary, a higher sensitivity analysis method is required to control the As concentration in Cu. One high-sensitivity As analysis method is hydride generationatomic absorption spectrometry (HG-AAS), in which gaseous hydrides (hydride vapor) are generated and separated by reaction of target elements such as As and selenium (Se) with hydrogen generated by hydrochloric acid (HCl) and a reductant (sodium borohydride: NaBH4). As one merit of HGAAS, this technique offers sensitivity approximately 1,000 times higher than that of conventional flame methods and thus has the advantage of enabling quantitation from around 1 ppb in the measurement solution. Herein we conducted a quantitative analysis of the trace amount of As contained in pure Cu by the HG method. Although Cu is generally an impediment to generation of hydrides of As, high-sensitivity measurement of As in Cu could be conducted easily by precipitation and separation of Cu in the sample preparation process.

October 1, 2020 GMT