关键词: 阳离子, 黄酒, 碱金属阳离子, 镁, 钙, 铵, 发酵, 酿造

Abstract: A new ion chromatographic (IC) method is developed for determination of alkali (Li+, Na+, K+), alkaline-earth metal (Mg2+, Ca2+) cations and ammonium in four types of alcohol beverages including yellow rice, white and red wines and beer. The separation of cations was performed on IonPac CG16 (50 × 5 mm ID) and IonPac CS16 (250 × 5 mm ID) columns connected in series with 30 mmol/L methanesulfonic acid as an eluent. The calibration plots obtained for conductivity detection of separated cations had good linearity (regression coefficients r2 > 0.9990) and good reproducibility with low values of relative standard deviation (RSD < 5.52, n = 6). The data of IC analysis indicated the presence of ammonium in 18 brands of yellow rice wines in concentration ranged from 137 to 284 mg/L and in beer and red wine at concentrations from 8.3 to 42.9 mg/L, while no ammonium was detected in white wine. A further investigation revealed that the elevated concentration of ammonium in yellow rice wine is due to the presence of proteins in raw material and it indicates the fermentation degree. At the same time no correlation between ammonium content and storage time was found for yellow rice wine. The concentration of alkali and alkaline-earth metals was the lowest for white wine as compared with other types of studied beverages, which could be due to the use of distillation during its production. It was also found that the concentration of K+ in red wine is significantly higher than in other types of the studied alcohol beverages, which is attributed to the higher content of potassium in red grapes.

Key words: cation, yellow rice wine, alkali metal cations, magnesium, calcium, ammonium, fermentation, brewing