气相色谱法测定清香型白酒中乙酸乙酯和乙缩醛含量的研究

采用内标法气相色谱对清香型白酒中的乙酸乙酯和乙缩醛含量进行检测时，由于两者极性非常相似，在普通毛细管色谱柱 上难以分离，因此通过对乙缩醛的酸性分解条件进行优化，实现白酒中乙酸乙酯和乙缩醛含量的同时测定。 结果表明，当水浴温度 30 ℃，水浴时间0.5 h，盐酸添加量为1%时，乙缩醛能充分分解。 在此条件下，酒样中乙酸乙酯和乙缩醛在体积分数在0.01%～0.40% 和0.005%～0.200%的范围内具有较好的线性关系（R2＞0.99），相对标准偏差（RSD）≤7.0%。 6种清香型白酒样品中乙酸乙酯的含量 为0.712～1.403 g/L，乙缩醛的含量为0.132～0.635 g/L。

Determination of ethyl acetate and acetal in Fen-flavor Baijiu by gas chromatography

The content of ethyl acetate and acetal in Fen-flavor Baijiu (Chinese liquor) was detected with internal standard by gas chromatography. It was difficult to separate the ethyl acetate and acetal in the common capillary column due to very similar polarity. Therefore, the ethyl acetate and acetal in Baijiu samples can be simultaneous determined by optimizing the acidic decomposition conditions of acetal. Results showed that the optimal experimental conditions were water bath temperature 30 ℃, water bath time 0.5 h, and hydrochloric acid addition 1%, the content of ethyl acetate in the Baijiu sample was measured under the experimental condition. The results indicated that the calibration curves for the ethyl acetate and acetal displayed a good linearity (R2＞0.99) in the volume concentration range of 0.01%-0.4% and 0.005%-0.2%, respectively. The relative standard deviations (RSD) were less than 7.0%. The ethyl acetate contents in 6 kinds of Fen-flavor Baijiu were 0.712-1.403 g/L, and the acetal contents were 0.132-0.635g/L.