Table 1 :
From: Improvement of bioprocess monitoring: development of novel concepts
Measurement principle | Target/Information | Vendor (commercial system e.g.) | Advantages | Disadvantages |
|---|---|---|---|---|
Paramagnetism | Oxygen/mass balancing | ABB Ltd CH-8050 Zurich Switzerland | Selectivity, stability | Desiccation of sample, delayed delivery of representative gas sample due to varying head space |
Dielectric spectroscopy | Membrane-enclosed biovolume | Aber Instruments (Biomass Monitor) | Good correlation to biomass | Signal influenced by variation of conductivity of fermentation broth |
2D-Fluorescence spectrometry | Typical intracellular substances involved in metabolic pathways | DELTA (BioView) | Capture of minute changes in chemical composition of the cell | Direct reading of process variables not possible multivariate data analysis required |
Infrared spectrometry | Typical intracellular substances | FossNIR-Systems (Model 6500) ABB (BOMEM MB160) | Spectral fingerprint of principle cellular constituents | Direct reading of process variables not possible multivariate data analysis required |
Mass spectrometry | Volatile organic compounds | Ionimed (PTR-MS) | Identification of chemical components, mass balancing enabled | Critical issue: sampling of head space |
Metal Oxide Field Effect Transistor | Volatile organic compounds | ALPHA M.O.S | Versatile sensor arrays | Direct reading of process variables not possible multivariate data analysis required |