Catharino Rodrigo Ramos, Haddad Renato, Cabrini Liliane Girotto, Cunha Ildenize B S, Sawaya Alexandra C H F, Eberlin Marcos N
Thomson Mass Spectrometry Laboratory, Institute of Chemistry, State University of Campinas, UNICAMP, SP, Brazil.
Anal Chem. 2005 Nov 15;77(22):7429-33. doi: 10.1021/ac0512507.
An improved approach for the direct infusion electrospray ionization mass spectrometry (ESI-MS) analysis of vegetable oils is described. The more polar components of the oils, including the fatty acids, are simply extracted with methanol/water (1:1) solution and analyzed by direct infusion ESI-MS in both the negative and positive ion modes. This fingerprinting analysis was applied to genuine samples of olive, soybean, corn, canola, sunflower, and cottonseed oil, to admixtures of these oils, and samples of aged soybean oil. ESI-MS fingerprints in the positive ion mode of the extracts divide the oils into well-defined groups, as confirmed by principal component analysis, whereas ESI-MS fingerprints in the negative ion mode clearly differentiate olive oil from the five other refined oils. The method is also shown to detect aging and adulteration of vegetable oils.
本文描述了一种改进的植物油直接进样电喷雾电离质谱（ESI-MS）分析方法。植物油中极性较强的成分，包括脂肪酸，只需用甲醇/水（1:1）溶液萃取，并通过直接进样ESI-MS在负离子和正离子模式下进行分析。这种指纹图谱分析应用于橄榄油、大豆油、玉米油、菜籽油、葵花籽油和棉籽油的真品样品、这些油的混合物以及老化大豆油样品。提取物在正离子模式下的ESI-MS指纹图谱将这些油分成明确的组，主成分分析证实了这一点，而负离子模式下的ESI-MS指纹图谱则能清楚地将橄榄油与其他五种精炼油区分开来。该方法还被证明能够检测植物油的老化和掺假情况。
