STUDIES OF THE CHROMIUM OXYGENATED CLUSTER IONS PRODUCED DURING THE LASER-ABLATION OF CHROMIUM OXIDES BY LASER-ABLATION IONIZATION FOURIER-TRANSFORM ION-CYCLOTRON RESONANCE MASS-SPECTROMETRY

Trivalent anal hexavalent chromium oxides have been examined by time-o f-flight laser microprobe mass spectrometry and Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). The positive-ion spec tra show a strong correlation with the valency of chromium in the oxid e. Thus, the positive cluster ion distribution and the presence. of ch aracteristic chromium cluster ions allow us to distinguish the two oxi des, Because of their important role in the formation of large chromiu m cluster ions, we have investigated the formation mechanism of precur sor ions such as CrO+. In this context, FTICRMS has been used to detec t the presence of singlet oxygen O-1(2)((1) Delta(g)) and to show its importance in the clustering process. Finally our hypothesis concernin g CrO+ formation involving the Cr+ ion and singlet oxygen O-1(2)((1) D elta(g)) was confirmed. (C) 1997 by John Wiley & Sons, Ltd.