Study of solution calibration of NIST soil and glass samples by laser ablation inductively coupled plasma mass spectrometry

A method for the determination of trace element concentrations by laser ablation inductively coupled plasma mass spectrometry (ICP-MS) using solution calibration and an internal standard has been studied and evaluated by analyzing NIST soil and glass samples. In most cases, the measured element concentrations were within +/-10% of the certified values. The internal standard was chosen on the basis of investigations of the proper signal intensity of certain isotopes and the homogeneity of their distribution in the sample. For soil samples, a matrix element, Mg, was chosen to be the internal standard. For glass samples, a trace element, Sr, was used as the internal standard. The results indicated that in both cases the internal standard was effective. Ni and Cu in soil gave poor results, while good results were obtained for Ni and Cu in glass samples. Time-resolved studies show that Ni gave many more signal spikes than other elements when the ablating laser moved across the surface of the soil sample. This observation indicates that one possible reason for the Door results was caused by the heterogeneity of the Ni distribution in the matrix.