PROFESSOR, AGRICULTURAL CHEMISTRY
B.S. Washington State University, 1963
Ph.D. Pennsylvania State University, 1967
Ionization processes, methodologies, and instrumentation employed in mass spectrometry are investigated in Dr. Barofsky's laboratory. Individual studies are structured around scientific problems in organic chemistry and biochemistry that require extensive use of mass spectrometry for their solution.Liquid matrix-assisted secondary ion mass spectrometry and fast atom bombardment mass spectrometry are widely used, sensitive analytical techniques. The ejection of deprotonated mononucleotides (dAMP or dGMP) from a glycerol matrix doped with the surfactant hexadecylpyridinium acetate and bombarded by various, energetic, monatomic and polyatomic, metal ions are being systematically studied. It has been discovered (1) that ion ejection is governed by nonlinear collision processes, (2) that the kinetics of this surfactant system are governed by a steady state between the competing processes of expelling ions from the surface and supplying ions from the bulk to the surface, and (3) that ionpairing with the surface active hexadecylpyridinium can be exploited to achieve a 10,000 fold increase in sensitivity for adenosine triphosphate.A central goal of molecular biology is to elucidate the molecular interactions between proteins and nucleic acids. Matrix-assisted laser desorption-ionization (MALDI) time-of-flight mass spectrometry is being applied to the analysis of covalent protein-nucleic acid complexes produced by ultraviolet (UV) crosslinking. It has been found (1) that certain protein-oligonucleotide complexes as large as 40,000 Daltons can be readily detected at a concentration of 1-2 mM in one microliter of an unpurified solution of the reactants after exposure to a single, 266 nm UV laser crosslinking pulse and (2) that mass spectrometric molecular weight determinations of photoaffinity labeled proteins can add directness and specificity to the ATPase inactivation assay normally used to monitor the formation of such complexes.