Abstract
A flow injection analysis (FIA) system for on-line monitoring of ethanol in cultivation media was developed, which combines the selectivity of a gas diffusion membrane with the substrate specificity of immobilized alcohol oxidase (AOD). The optimization of membrane material and immobilized enzyme was performed using different FIA modes such as dual detection and dual injection. A simple modification of a polypropylene membrane with silicone enabled a very flexible adjustment of the linear range for alcohol detection between 0.0006 and 60% (v v-1). The ethanol content of cultivation media could be determined continuously with a frequency of 120-180 samples per hour with an excellent correlation to gas chromatographic analysis (r = 0.9996). The relative standard deviation for 10 successive injections was lower than 0.5%.
Collapse