Oxychlorine ions in inductively coupled plasma mass spectrometry: effect of chlorine speciation as Cl? and ClO4 ?

Differences in the inductively coupled plasma mass spectra of 0.2 mol l–1 HCl and 0.2 mol l–1 HClO4 are reported. An enhancement was observed of the ion signal in the mass spectra of several oxychlorine species (ClO2+, HClO2+, ClO3+, HClO3+, HClO4+ and H2ClO4+) in a solution of HClO4 compared with the spectra of an equimolar solution of HCl. Spectra of Ca in HClO4 showed enhanced formation of CaClO+, CaClO2+, CaClO3+ and CaClO4+ compared with equimolar solutions of Ca in HCl. Similarly, solutions of Mg in HClO4 showed enhanced formation of MgClO2+, MgClO3+ and MgClO4+ compared with equimolar solutions of Mg in HCl. Other major rock-forming elements (Na, Al, K, Sc, Ti, Mn and Fe) did not produce enhanced signals from oxychlorine polyatomic ions.