Correction strategies over spectral interferences for arsenic determination in aqueous samples with complex matrices by quadrupole ICP-MS

Abstract

A study has been conducted for the determination of arsenic by inductively coupled plasma mass spectrometry (ICP-MS) in natural waters with high sodium and chloride content. Spectral interferences on arsenic measurement have been investigated. The use of arithmetic corrections is necessary when no gas is used in the collision/reaction cell, but it does not completely eliminate persistent interferences produced in the plasma. A modification should be made when this correction is used together with a pressurised collision/reaction cell. The matrix effect produced by the presence of high amounts of sodium has been corrected using rhodium as internal standard. The proposed methodology has been successfully applied to the determination of arsenic in spiked, certified and natural waters with high chloride and sodium content.