Abstract The abundance of metal argide (MAr + ) ions during laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is measured during ablation of pure samples of transition metals. As expected, the relative abundance of MAr + ions to M + ions for various elements increases as the dissociation energy (D 0 ) of the ion increases. Gas kinetic temperatures (T gas ) are determined from the calculated MAr + /M + ratios and are used to indicate the origins of MAr + ions. The determined T gas values are very high, 8000 K to ≥ 20,000 K, which indicate that MAr + ions are much less abundant in the mass spectrum than expected based upon plasma conditions. Collision-induced dissociation (CID) during the ion extraction process is suggested to be responsible for removal of MAr + ions. Factors responsible for these collisions are discussed.