MASS SPECTROMETRY/MASS SPECTROMETRY: APPLICATIONS AND NEW INSTRUMENTATION

GARY LEE GLISH, Purdue University

Abstract

Mass spectrometry/mass spectrometry (ms/ms) is a relatively new analytical technique that is presently undergoing a rapid expansion. This work deals with two areas of the growth, instrumentation and applications. A new ms/ms instrument was constructed, a hybrid instrument consisting of a magnet and two quadrupoles, and is termed a BQQ mass spectrometer. This indicates one of the modes of operation, although several others are discussed. These other modes are possible because of the modular form in which the instrument was built. This instrument has already shown great potential for the study of the collision-induced dissociation (CID) phenomenon. It has been found that variation of the ion kinetic energy, in the ten to hundreds of electron volts, varies the amount of internal energy deposited in the ion and therefore the amount of fragmentation. The use of ion kinetic energy was shown to have potential applications for determination of appearance potentials of ion/molecule association products formed in ms/ms reactions. The use of ms/ms in conjunction with ion/molecule association reactions for differentiation of structural isomers was also demonstrated. As another application of ms/ms to ion/molecule reactions, several reactions occurring in the chemical ionization source were characterized. Two different ms/ms instruments were used for the latter ion/molecule reaction studies. One of these instruments consisted of two quadrupoles in series with a collision cell between them. The other instrument was a reverse geometry double sector instrument (magnetic sector followed by electric sector). Studies were also performed on all three instruments to evaluate the utility of ms/ms for direct mixture analysis. Examples of rapid, multi-sample analysis for trace components are illustrated as well as direct analysis of a complex mixture.

Degree

Ph.D.

Subject Area

Analytical chemistry

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