Simultaneous determination of wine sugars, glycerol and organic acids¹³C/¹²C isotopic ratio by ion chromatography-co-IRMS

Abstract

Abstract. Ion chromatography (IC) isotope ratio mass spectrometry (IRMS) coupling is possible using a liquid interface allowing chemical oxidation (co) of organic compounds. Synthetic solutions containing a mixture of glycerol, sugars (sucrose, glucose and fructose) and organic acids (gluconic, lactic, malic, tartaric, oxalic, fumaric, citric and isocitric) were elaborated to estimate analytical applications of two different IC systems. It appears that the use of carbonated solution in the eluting phase is a perturbation for 13 C isotope measurements as it creates a δ 13 C deviation from the expected values. A sample of authentic sweet wine was analyzed by IC-co-IRMS using KOH gradient. Ratios of isotopic, ratios of organic acids and glycerol was found to be, in average, equal 1.01 ± 0.04 that is in accordance with our previous results.