摘要：研究了点特异性天然同位素分馏核磁共振分析法（SNIF-NMR）鉴别酒类真伪及掺假的方法。包括乙醇的SNIF-NMR直接分析和乙酸乙酯的固相萃取（SPE）净化富集后SNIF-NMR分析两部分。乙醇的SNIF-NMR检测。以两种葡萄酒和两种白酒、以及四种实验室乙醇试剂为样品，考察了乙醇的SNIF-NMR分析方法。核磁共振氢谱检测条件为：脉冲宽度P1=14。1，延迟时间d1=1s，扫描次数NS=32，谱宽SW=20ppm，中心频率O1=3090Hz，采样时间AQ=3。17s。NMR测定乙醇中亚甲基氢峰面积（ACH2）与甲基氢峰面积（ACH3）比值的结果显示，葡萄酒的比值为0。72-0。77，白酒为0。66-0。68，而试剂乙醇的值为0。64-0。67。显示SNIF-NMR方法能够辨别出天然乙醇和合成乙醇的区别，在红酒的检测中尤其明显。己酸乙酯是浓香型白酒的主体香气成分，是假酒浓香型白酒的主要掺假成分，但含量较低。实验中采用固相萃取方法，选用大孔吸附树脂D101作为SPE柱材料。酒样过SPE柱后用正己烷淋洗，80%甲醇洗脱净化富集。以两种白酒和己酸乙酯试剂（作为对照）为样品，考察了己酸乙酯的SPE-SNIF-NMR分析方法。SNIF-NMR检测条件除扫描次数NS=256外，其它与乙醇的条件相同。结果测定试剂己酸乙酯的NMR谱图与酒样SPE处理后得到的NMR谱图差异明显，但这种差异可能来自酒中不同成分，酒的己酸乙酯NMR峰存在干扰，需要进一步研究。本实验研究为SNIF-NMR用于白酒鉴别提供了重要数据。82409

毕业论文关键词：固相萃取；核磁共振波谱；酒；己酸乙酯；乙醇

Identification of Synthetic Additives in Natural Food by Site specific nuclear isotope fractionation as measured by nuclear magnetic resonance

Site specific nuclear isotope fractionation as measured by nuclear magnetic resonance(SNIF-NMR) was used to identify the authenticity and adulteration of alcohol。 Including SNIF-NMR direct analysis of ethanol and solid phase extraction (SPE) purification of ethyl acetate after enrichment and SNIF-NMR analysis of two parts。 Ethanol was detected by SNIF-NMR。 The SNIF-NMR method of ethanol was investigated by using two kinds of wine and two kinds of liquor, and four kinds of laboratory ethanol reagents。 The detection conditions were as follows: pulse width P1 = 14。1, delay time d1 = 1s, scanning frequency NS = 32, spectral width SW = 20ppm, center frequency O1 = 3090Hz, sampling time AQ = 3。17s。 NMR analysis of the ratio 

of methylene hydrogen peak area (ACH2) to methyl hydrogen peak area (ACH3) in ethanol showed that the ratio of the wine was 0。72-0。77, the white wine was 0。66-0。68, and the value of the reagent ethanol was 0。64-0。67 ，The The SNIF-NMR method shows that the difference between natural ethanol and synthetic ethanol can be distinguished, especially in the detection of red wine。 Ethyl caproate is the main aroma component of Luzhou-flavor liquor, which is the main adulterant ingredient of Liquor-flavor liquor, but the content is low。 In the experiment, solid-phase extraction method was used, and macroporous adsorption resin D101 was used as SPE column material。 After passing the SPE column, rinse with n-hexane and purify and purify with 80% methanol。 The SPE-SNIF-NMR analysis of ethylhexanoate was carried out using two kinds of white liquor and ethyl caproate reagent (as a control)。 SNIF-NMR detection conditions except for the number of scanning NS = 256, the other with the same conditions of ethanol。 The results showed that the NMR spectra of ethylhexanoate and the NMR spectra obtained by the SPE treatment were different。 However, this difference might be due to the interference of the different components of the alcohol, the ethyl acrylate NMR peak, and the need for further study， The study provides important data for SNIF-NMR for liquor identification。

Keywords：Solid phase extraction；nuclear magnetic resonance spectroscopy；alcohol；ethyl caproate；ethanol