SEMI-ON-LINE ANALYSIS FOR FAST AND PRECISE MONITORING OF BIOREACTION PROCESSES

Monitoring of substrates and products during fermentation processes ca n be achieved either by on-line, in situ sensors or by semi-on-line an alysis consisting of an automatic sampling step followed by an ex situ analysis of the retrieved sample. The potential risk of introducing t ime delays and signal bias during sampling makes it necessary to disti nguish between real-time, on-line, in situ methods and semi-on-line an alysis. In addition, semi-on-line analyzers are often mechanically com plex-a circumstance which has to be given special attention during the ir industrial use on a routine basis. This review on semi-on-line anal ysis will focus both on the dynamics and precision of aseptic sampling devices and on the performance of flow injection analysis (FIA) and s equential injection analysis (SIA), especially with regard to their ro bustness when used in industry. (C) 1996 John Wiley & Sons, Inc.