LASER-INDUCED BREAKDOWN SPECTROMETRY OF VANADIUM IN TITANIA-SUPPORTEDSILICA CATALYSTS

The capability of laser induced breakdown spectrometry (LIBS) for vana dium determination in a xV-2TiO(2)-SiO2 catalyst is presented. The mic roplasma was generated onto the sample surface using a pulsed Nd:YAG l aser operating in the second harmonic (532 nm). Laser produced plasmas were collected and detected using a charge-coupled device (CCD). In o rder to minimize the complex spectral interferences of emission lines and matrix effects a wide spectral range (210-660 nm) was studied. The focusing of the laser beam on the surface was optimized to improve th e signal-to-background ratio, and consequently the limit of detection. The analytical lines selected were used to evaluate the calibration c urve. The detection limit for V was estimated to be 38 mu g g(-1) in 2 TiO(2)-SiO2. The method precision expressed as relative standard devia tion (RSD) was better than 6% in the concentration range 200-1000 mu g g(-1). (C) 1998 Elsevier Science B.V. All rights reserved.