MODIFIED ZEOLITES FOR MASS-SPECTRAL ANALYSIS OF TRIBUTYL-PHOSPHATE USING IN-SITU SILVER ION CHEMICAL-IONIZATION

The use of silver ion exchanged zeolites for the sampling al-id subseq uent analysis of tributyl phosphate (TBP) by laser desorption-mass spe ctrometry is presented. This technique, which should be generally appl icable to any organic molecule that undergoes facile reaction with met al cations, uses silver counter ions in the zeolites as chemical ioniz ation reagent ions to form metal cationized pseudomolecular ions of tl -Le molecule sorbed by the zeolite. Resonant laser ablation was used t o selectively generate Ag+ from the zeolite sample to reduce the numbe r of unwanted ions injected into the ion trap, although conventional d esorption ionization can be used to create metal cations. The experime nt is simple to implement, and provides a strong ion signal fur the Ag (TBP)(+) adduct species. Mass spectrometry/mass spectrometry provides data necessary for compound identification. Adsorption of TBP based up on zeolite pore size was modeled for two zeolite structures and their ability to accept TRP into their pore volumes; these computational res ults are strongly supported by the experimental data presented here. ( C) 1997 American Society for Mass Spectrometry.