Fabrication of solid calibration standards by a sol–gel process and use in laser ablation ICPMS

Abstract

A method for the fabrication of solid multi-element calibration standards by a sol–gel process, suitable for laser ablation ICPMS, is described. The addition of an analyte (Se) and an internal standard (S) to a normal sol–gel method does not impair the production of the glass-like discs (xerogels). Heterogeneity of Se and S concentrations in the xerogels is less than that of NIST SRM 610 and 612 glass standards. Small differences in slopes of calibrations based on sulfide standards and those based on xerogel standards reflect differential matrix effects. The calculated S contents in the NIST SRM 610 (634 ± 151 µg g⁻¹) and 612 (133 ± 17 µg g⁻¹), using the xerogels as standards, are comparable to available S concentration data. Multiple element standards of Se, S and transition metals are hampered by the formation of inclusions resulting in visible heterogeneity, limiting the concentrations of transition metals with Se and S in the xerogels. The xerogels are potential standards for a variety of elements in glasses, minerals and other materials