Page 8 - 4_TOC special applications

Sum parameter – Total Organic Carbon

Carbon dioxide determination in beer

SCA-130-403

Carbon dioxide is an important ingredient in In order to develop a method that does not
many soft drinks. This is also the case for have these disadvantages, a TOC analyzer
beer. It creates a sparkling and refreshing was used.
(tangy) taste and is important for the
formation of foam. ■ Innovative methods
In this method, the sample (beer) is directly
The CO 2 content of a beer affects the placed in a 40 mL autosampler vial. 5 mL of a
threshold values for various fragrance and 32% NaOH solution was added to the
aroma components. In addition, bottling autosampler vial to preserve the CO 2.
under CO 2 increases the shelf life of beer..
The sample is subsequently added directly to
the autosampler and the IC (inorganic
carbon) content is measured.

Preservation step:
In the manual of the ‘central- European
brewery technological analysis commission)’
(MEBAK) various methods for the - -
determination of CO 2 are listed. These are CO + OH → HCO
3
2
generally based on manometric or titrimetric
method, or they are methods that use - 2-
specialized detectors. CO + 2 OH → CO + H O
2 3 2
Disadvantages of these methods are often
the lack of selectivity for CO 2 (other gases or In the TOC analyzer, the sample is injected in
substances are also determined), high a concentrated phosphoric acid solution
expenditure in terms of personnel and time, (25%). The CO 2 is subsequently released
and the lack of possibilities for automation. again and is transferred via the carrier gas to
a CO 2-selective NIDR detector where it is
detected.