Determination of Ag, Tl, and Pb in few milligrams of platinum nanoclusters by on-line isotope dilution in laser ablation inductively coupled plasma mass spectrometry

A new analysis procedure for determination of trace impurities in a few milligram noble metal nanoclusters, using on-line isotope dilution in laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) was developed. During the laser ablation of investigated sample simultaneous the dry aerosol of nebulized enriched isotope spike solution was added and mixed in the laser ablation chamber. The capability of solution-based calibration by a modified isotope dilution analysis in LA-ICP-MS for the determination of selected elements was tested, using platinum reference material NIST SRM 681. A good agreement of measured with certified concentration for Ag and Pb was found. The detection limits for trace element determination of the developed analytical technique, using LA-ICP-MS with quadrupole analyzer varied between 6 ng g(-1) for Ag and 90 ng g(-1) for Pb. The analytical technique was applied for the determination of Ag, Tl, and Pb in a few milligram of platinum nanoclusters. (C) 2004 Elsevier B.V. All rights reserved.