Analysis of the ¹³C natural abundance of CO₂ gas from sparkling drinks by gas chromatography/combustion/isotope ratio mass spectrometry

Abstract

A simple and rapid method to measure naturally occurring delta(13)C values of headspace CO(2) of sparkling drinks has been set up, using direct injections on a gas chromatograph coupled to an isotope ratio mass spectrometer, through a combustion interface (GC/C/IRMS). We tested the method on CO(2) gas from several origins. No significant isotopic fractionation was observed nor influences by secondary compounds eventually present in the gas phase. Standard deviation for these measurements was found to be <0.1 per thousand.

GasBench/isotope ratio mass spectrometry: a carbon isotope approach to detect exogenous CO2 in sparkling drinks

“…For wines where C3 sugars had probably been added, the average d 13 C value was À22.0 AE 0.8% (n ¼ 16), with individual values ranging from À20.30 to À23.63%, as previously reported, 1 and the wine where C4 sugars had probably been added showed a CO 2 value of À9.62%, close to the values reported for sparkling wines produced with cane sugar. 1,6,7,17 No significant differences ( p > 0.05) were found corresponding to the different types of cava-brut nature, brut reserve and brut.…”

“…5 For several fermented products, CO 2 reflects the botanical origin of the sugars from which the gas originates. 6 Cane sugar is a C4 plant while the grapevine is a C3 plant. It is thus possible to distinguish by IRMS between the CO 2 produced from the fermentation of the sugar present in the grape must and that originating from added cane sugar.…”

“…The d 13 C values will lie in the following ranges: CO 2 originating from carbonates (values close to 1%); CO 2 from combustion of natural gas (up to À75%). 6,8 Consequently, the 13 C/ 12 C isotope ratio of CO 2 from sparkling wine is determined by the type of sugar used in the second fermentation (C3 or C4) or by the isotopic composition of the industrial CO 2 added.…”

“…A continuous flow method has also been described, but it still required a dedicated on-line system with a cryogenic trap and a vacuum line. 15 Some of these technical difficulties have been overcome by a recent method developed by Calderone et al 6 and adopted by the EU and the Organisation International de la Vigne et du Vin (OIV) as an official method. 16 This method can be used to measure naturally occurring d 13 C values of the headspace of sparkling drinks, but it still requires a previous CO 2 gas extraction from the sample.…”

Exploratory Analysis of Sparkling Wines Based in the Combined Data of Stable Isotope Analysis with Physicochemical Variables and Volatile Profile

“…They have concluded that the measurement of δ 13 C values could be used to differentiate the content of grape or C4 sugar added to the product and that the carbon isotope ratios of European and South American sparkling wines were significantly more depleted of 13 C than Brazilian wines. In an innovative approach, Calderone et al 20 present an advantageous method for analyses the δ 13 C values of CO 2 from the headspace of sparkling drinks wherein headspace sampling is followed by direct injection of the sample into a gas chromatograph with an isotope ratio mass spectrometer, through a combustion interface (GC-C-IRMS); this configuration requires no purification and presents good reproducibility. Already Adami et al 16 present a method which, from the isotopic ratios of δ 13 C of the ethanol and δ 18 O of the water content of wine, was capable to find the relationship between the grape variety, the wine type and the geographic location.…”