Technical Summary: Industrial Ethanol Analysis (Bulletin ref. TB01944K)
 

A rapid high performance ethanol analysis based on the direct reaction with the enzyme Alcohol Oxidase (AOD). Applications include brewing, flavourings, pharmaceuticals, toiletries etc.
 

Name:
 

Ethanol
 

Codes:

GMRD-110(I)
GMRD-110(IJ)
GMRD-112
 

50ml
8 x 50ml
4 x 175ml
 

70 analyser cycles (28 cycles - AM2)
560 analyser cycles (224 cycles - AM2)
1000 analyser cycles (412 cycles - AM2)
 

Instruments:
 

AM2/AM3/GL6/GM8 Series analysers
 

Principle:

In the presence of molecular oxygen, ethanol is oxidised by the enzyme alcohol oxidase to acetaldehyde and hydrogen peroxide:
 

Under the conditions of the assay, oxygen consumption is directly proportional to ethanol concentration.
 

Samples:
Sample volume:

Aqueous samples including beers, wines, cough mixtures, tonics, shampoos
Dependent on concentration range to be measured (typically 10 µl injected from 1:10 aqueous dilution)
 

Analysis time:
Analytical Range:
Precision:
 

20 - 25 seconds
0 - 10 %VV (AM3); 0 - 40 %VV (AM2)
Typical within-run S.D. = 0.055 @ 9 %VV
 

Accuracy:

Beer comparison vs Reference Distillation (range 2 - 11 %VV):
y (Analox) = 1.006x + 0.005 %, r = 0.9998
 

Reagent Stability:

Shelf-life 6 months unopened when stored at 0 - 5°C. After reconstitution,
ca 5 days for AOD/buffer reagent if stored at 0 - 5°C between use.  Fresh aliquots may be frozen for several weeks at - 20°C or lower to extend life.
 

Note:

i) Alcohol oxidase is non-specific towards ethanol. This assay will also detect other low molecular weight alcohols, e.g. methanol.
ii) Primary calibrating standards, 0.1 - 15 %VV are available separately, as required.