| Name: | Description: | Size: | Format: | |
|---|---|---|---|---|
| 135.83 KB | Adobe PDF |
Advisor(s)
Abstract(s)
A flow injection method was developed for the sequential enzymatic determination of ethanol and glycerol in wines, using
immobilised ethanol dehydrogenase and glycerol dehydrogenase, respectively. The enzymes were immobilised separately on
alkylaminated controlled pore glass. A multi-site spectrophotometric detection system was used in parallel configuration to
monitor the absorbance change in the two independent analytical channels. A 50-fold dilution of the samples was necessary
before injection. The working range was between 0.05 and 0.5% (v/v) for the ethanol and between 0.03 and 0.3 g l−1 for the
glycerol determination, with corresponding detection limits of 2 10−3%(v/v) and 2 10−3 g l−1. Relative standard deviations
(R.S.D.) (nD9) lower than 2.3% for the ethanol and 2.1% for the glycerol determination were found. For 13 samples of different
types of table and Port wines, the results showed good agreement with the corresponding reference procedures; a two level
recovery study also showed good accuracy for the developed methods. The sampling rate was 10 h−1, corresponding to 20
determinations per hour
Description
Keywords
Sequential flow injection Ethanol Glycerol Multi-site detection Spectrophotometric enzymatic analysis Wine
Pedagogical Context
Citation
RANGEL, António O. S. S.; TÓTH, Ildikó V. - Enzymatic determination of ethanol and glycerol by flow injection parallel multi-site detection. Analytica Chimica Acta. ISSN 0003-2670
Publisher
Elsevier