Chemical Reaction Monitoring with the AccuTOF-DART™ Mass Spectrometer
Introduction
DART provides a convenient means for monitoring the progress of chemical reactions. Reactants, intermediates, products and byproducts can be detected by simply dipping a glass rod into the reaction pot and then placing the rod in front of the DART ion source. The AccuTOF's ability to measure accurate masses and isotopic abundances makes it possible to confirm or identify the elemental compositions of peaks in the mass spectra. Here we show the use of AccuTOF-DART to monitor the acetylation of 1,2-hexanediol as a function of time.
Experimental
600 μl of 1,5-hexanediol (4.9 mmol) was mixed with 700 μl (12.3 mmol) of glacial acetic acid and one drop of concentrated sulfuric acid in a loosely capped scintillation vial. The reaction was slowly warmed with a heat gun and a fume vent was positioned over the reaction vial and the DART source. Samples were taken periodically for analysis with the AccuTOF-DART by sipping a melting point tube into the reaction mixture and placing the tube in front of the DART ion source for a few seconds. The reaction progress was monitored by plotting the fractional abundances of the protonated molecules (MH+) as measured for each component in the mass spectra.