Bioreactor monitoring using flow injection/membrane introduction mass spectrometry with an ion trap detector

Membrane introduction mass spectrometry with flow injection analysis (FIA) sampling has been utilized for on-line monitoring of the principal solution phase products of fermentation from the Klebsiella oxytoca microorganism. A flow injection sampling system was used to control delivery of fermentation broth or an external standard to the ion trap detector mass spectrometer. Analyte introduction occurred via a membrane probe in which the aqueous solutions flowed past a membrane located contiguous to the ion trap detector. Analytes which permeate the membrane were ionized by chemical ionization. The concentrations of the liquid phase products acetic acid, acetoin, 2,3-butanediol and ethanol were monitored as a function of time and quantified relative to external standard solutions. Off-line gas chromatography was utilized to test the accuracy of these measurements and excellent agreement was found. Products of fermentation by the organism Clostridium acetobutylicum have also been examined.