Larimax have developed a complete multicomponent, multichannel gas analysis system specifically designed for the gas analysis of processes such as fermentation and cell culture.

The latest DQC 2000 computer integrated mass spectrometer is used and this instrument features a colour VDU, easy to use mouse operated software, and a valve manifold which permits up to 32 gas streams to be connected to the central vacuum system for analysis. 

The user can select up to 16 gases of interest in peak select mode, although oxygen and carbon dioxide are frequently the only two needed, and the switching from one channel to another is controlled by sequencing software incorporated into the standard computer control package. 

The user can select changeover delays to allow for reading stabilisation after switching channels, then the number of readings required before moving on to the next channel can be programmed.

Data logging is independently selectable and allows gas concentration information to be logged onto the computers floppy or hard disc under specific batch numbers, time, date and channel identification.

MEMBRANE PROBE FOR THE ANALYSIS OF DISSOLVED SPECIES

The BIOQUAD not only offers tremendous flexibility in the monitoring of multiple off gas streams but can also be supplied with a membrane probe to allow the analysis of gases and volatiles extracted directly from the fermentation broth.

The membrane probe used for this work consists of a stainless steel holder that fits into standard DN 25 ports on bioreactors. The probe has a replaceable stainless steel membrane holder and the gases that permeate through the membrane are taken to the mass spectrometer analyser by a carrier gas. If gases or volatiles other than those present in air that are of interest then air itself can be used as a carrier gas, otherwise helium or some other gas that does not interfere with the analysis may be chosen.

Because the probe does not involve high vacuum operation, it is easy to incorporate multiple probes to the same multichannel inlet system as for off gas analysis.