Fragmentation of Benzyl Pyridinium Salts by Paper Spray Ionization
Undergraduates: Kim Dang, Khang To
Faculty Advisor: Gary Glish
Department: Chemistry
Paper spray is a relatively new ambient ionization technique used to generate ions for the detection by mass spectrometry. Analytes are deposited onto a paper substrate laser cut to a sharp tip, and ions are produced from the emitter when a spray solvent and high voltage is applied to the paper. The technique has been used for a variety of applications, however the amount of energy imparted to analytes ionized this way is not well characterized. Fragmentation occurs when ions gain enough internal energy to break bonds. The well-studied ¿¿¿thermometer ion¿¿¿ methoxybenzyl pyridinium is used to investigate the amount of internal energy imparted by paper spray ionization. Benzyl pyridinium salts have a permanent charge and fragment by simple cleavage, with the amount of energy required for fragmentation being related to the substituent on the pyridine. Both commercialized (Velox 360) and custom-built paper spray instruments are used to test variables that can affect the amount of fragmentation. Some of these variables include the distance from the tip to the inlet of the mass spectrometer in xyz directions, temperature of the inlet, and the total voltage applied.