Study of Solution Calibration of NIST Soil and Glass Samples by Laser Ablation Inductively Coupled Plasma Mass Spectrometry

Abstract

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 poor results was caused by the heterogeneity of the Ni distribution in the matrix.

Laser ablation in analytical chemistry—a review

“…Bi et al [67] Poor accuracy was observed for Cu and Ni in soil samples, whereas good results were obtained for these elements in glass samples. The cause of the error was believed to be due to the heterogeneity of elements in the sample.…”

Infrared laser ablation study of pressed soil pellets with inductively coupled plasma atomic emission spectrometry

“…Differences in the ablation behavior of analytes known as elemental fractionation can be diminished by internal standardization in combination with a suitable binder [9]. Few applications have been published on laser ablation of soils either with ICP-AES [5,10] laser-induced breakdown spectroscopy [11] or ICP-MS [12,13,14]. In contrast to rocks, ores, or minerals, soils represent more complicated matrices because of significant and variable content of organic matter.…”

“…The following approaches can be presented as typical examples: i) closely matrix-matched calibration with solid reference materials in LA-ICP-AES of geochemical samples [3] and soils [5]; ii) matrix-matched calibration with uncontaminated natural matrix spiked with analytes, both as solutions and solid certified reference materials in the LA-ICP-MS of road sediments [6] and in the LA-ICP-AES analysis of agricultural soils [6]; iii) liquid-solid calibration in the analysis of soils by LA-ICP-AES [5] and LA-ICP-MS [14].…”

A new method for the SI-traceable quantification of element contents in solid samples using LA-ICP-MS

“…For lead the authors encountered some not specied problems: the result differs 35% from the certicate. 33 The determined recovery of the results with respect to the certicate became worse with increasing mass of the analyte element. In our work, using the solid sample itself as the reference material, no signicant dependence of the recovery on the element mass was observed (Pb in SRM 612: 7%).…”