The contamination of carbon dioxide used for carbonation, container headspace filling, etc., with traces of oxygen can have detrimental effects on beer quality. However, many breweries use the Zahm-Nagel method of determining carbon dioxide purity, which does not specifically detect oxygen. A portable instrument suitable for both field and laboratory use, the Neutronics "Trace Oxygen Analyzer", is described. Statistical comparison of the results obtained from 34 carbon dioxide samples using this instrument with the determination of the oxygen contents of the same samples by gas chromatography produced a correlation coefficient of 0.953, showing the analyser to be almost equal in accuracy and sensitivity to the Gow-Mac Series 150 gas chromatograph used in the tests. Moreover, it has a built in sampling pump which allows it to analyse samples from vessels or containers with internal pressures too low to permit sampling by either the gas chromatograph or the Zahm-Nagel apparatus.
Keywords : analysis carbon dioxide comparative test equipment oxygen