The effect of quadrupole ICPMS interface and ion lens design on argide formation. Implications for LA-ICPMS analysis of PGE's in geological samples

Abstract

The argide levels in laser ablation ICPMS were found to vary 30 times between commonly used quadrupole ICPMS, while other polyatomic interferences like oxides vary less than 3 times. Investigating important parameters revealed that the pressure between skimmer and extraction lenses is key to a low argide rate. The Agilent 7700x with a relatively high pressure due to the restricted gas flow and a small volume between skimmer and ion lenses has the lowest argide levels. The relatively high pressure allows more collisions and breaking apart of weakly bound argide ions. Apparent light PGE (ruthenium, rhodium and palladium) concentration from cobalt, nickel, copper and zinc argides was estimated to be up to 0.00025 times the metal concentration.