近红外光谱和气相色谱-质谱联用技术对橄榄油掺杂及品质分析研究

分别采用近红外光谱技术及气相色谱-质谱联用技术对橄榄油样品进行分析。采用透射方式采集橄榄油样品的近红外光谱比漫反射方式可以获得更好的重现性;通过直观分析、二阶求导以及主成分分析可快速判别橄榄油与掺杂橄榄油。0.10 g橄榄油样品经过10 mL的KOH-甲醇溶液甲酯化处理后,加入10 mL正己烷和10 mL水进行液液萃取,并对正己烷提取液进行气相色谱-质谱分析,对39种橄榄油脂肪酸甲酯含量的分析结果与近红外光谱的主成分分析图对比得出,油酸和亚油酸是影响橄榄油近红外光谱扫描结果的主要成分。

Adulteration and Quality Analysis of Olive Oil by Near-Infrared Spectrometry and Gas Chromatography-Mass Spectrometry

Olive oil was analyzed by near-infrared spectrometry and gas chromatography-mass spectrometry.The reproducibility of near-infrared spectrum acquired through transmission is better than that acquired through diffuse reflection.The adulteration of olive oil was differentiated rapidly by visual analysis,derivation of two order analysis and principal component analysis（PCA）.0.10 g of olive oil was added 10 mL of KOH-methanol to methyl-etherification.Then 10 mL of n-hexane and 10 mL of water were added to liquid-liquid extraction.The extracts of n-hexane were analyzed by gas chromatography-mass spectrometry and the fatty acid methyl ester（FAME） of 39 olive oil samples were compared with the PCA of near-infrared spectrometry.The results indicated that oleic acid and linoleic acid were major impact components to the near-infrared spectrums of olive oil.