ANALYTICAL ATOMIC SPECTROSCOPY USING ION-TRAP DEVICES

Investigations using ion trap devices for analytical atomic spectrosco py purposes have focused on the use of an inductively coupled plasma ( ICP) ion source with ion trap mass spectrometric (ITMS) detection. Ini tial studies were conducted with an instrument assembled by simply app ending an ion trap as the detector to a fairly conventional ICP/MS ins trument, i.e. leaving an intermediate linear quadrupole between the pl asma source and the ion trap. The principal advantages found with this system include the destruction of nearly all problematic and typical ICP/MS polyatomic ions (e.g., ArH+, ArO+, ArCl+, Ar-2(+), etc) and a d ramatic reduction of the primary plasma source ion, Ar+. These results prompted the development of a second-generation plasma source ion tra p instrument in which direct coupling of the ICP and ion trap has been effected (i.e. no intermediate linear quadrupole); the same performan ce benefits have been largely preserved. Initial operation of this ins trument is described, characterized, and compared to the originally de scribed ICP/ITMS and conventional ICP/MS systems. In addition, experim ents aimed at improving ICP/ITMS sensitivity and selectivity using bro adband resonance excitation techniques are described. Finally, the pot ential for laser optical detection of trapped ions for analytical purp oses is speculated upon.