Abstract
The AOAC official methods for determination of carbon dioxide in wine are time-consuming, relatively complex, and may not be suitable for newer wine products with higher levels of carbonation. A different procedure was collaboratively studied. In this method, NaOH is added to convert CO2, in the wine to the carbonate form. The solution is then titrated with a standard H2S04 solution, and the titer is recorded between pH 8.6 and 4.0. A degassed sample of the same wine is analyzed in the same manner to provide a blank, and that titer is subtracted before the C02 concentration is calculated. Ten laboratories participated in the collaborative study. Each laboratory received 6 pairs of coded samples covering a range of approximately 200 to 380 mg CO2/100 mL. The results from 2 laboratories were excluded as outliers. Although the samples used were commercially produced wines whose carbon dioxide content can vary due to normal bottling equipment variations, average standard deviations for reproducibility and repeatability were 10.97 and 9.96, respectively. The method has been adopted official first action.