Development of an On-Line Pyrolysis Mass Spectrometry System for the On-Line Analysis of Fermentations

Abstract

Mass spectrometry has been used already in a number of ways to analyse fermentations:

• with a capillary inlet for gas measurement, to monitor the feed and the exhaust gas concentrations, thus allowing gas balances over the reactor to be established (Heinzle et al., 1984)

• with a membrane inlet as a probe for volatile compounds dissolved in fermentation broth (Reuss et al., 1975; Weaver, 1982; Bohatka et al., 1983; Heinzle et al., 1985a)

• to characterize states of a fermentation using off-line pyrolysis mass spectrometry and factorial analysis (Heinzle et al.,1985b; Meuzelaar et aí.,1982)

There is, however, no good method existing to routinely analyse non volatiles in fermentation liquid using mass spectrometry. The main problem is to reproducably introduce such compounds into the high vacuum of the mass spectrometer. The aim of the presented work was to develop an analytical method based on pyrolysis mass spectrometry to monitor on-line concentrations of non-volatile components in a fermentation system.