Dipartimento di Scienza e Tecnologia del Farmaco , Università di Torino , Turin , Italy.
J Agric Food Chem. 2019 Feb 13;67(6):1619-1630. doi: 10.1021/acs.jafc.8b06601. Epub 2019 Jan 30.
The volatile fraction of foods and of plant-origin materials provides functional information on sample-related variables, and gas-phase extractions are ideal approaches for its accurate chemical characterization. However, for gas-phase sampling, the usual procedures adopted to standardize results from solvent extraction methods are not appropriate: headspace (HS) composition depends on the intrinsic physicochemical analyte properties (volatility, polarity, partition coefficient(s)) and matrix effects. Method development, design, and expression of the results are therefore challenging. This review article focuses on volatile vapor-phase quantitation methods (internal standard normalization, standard addition, stable isotope dilution assay, multiple headspace extraction) and their suitability in different applications. Because of the analyte informative role, the different ways of expressing results (normalized chromatographic area, percent normalized chromatographic areas, and absolute concentrations) are discussed and critically evaluated with examples of quality markers in chamomile, process contaminants (furan and 2-methylfuran) in roasted coffee, and key-aroma compounds from high-quality cocoa.
食品和植物源材料的挥发性部分提供了与样品相关变量的功能信息，而气相提取是准确化学表征的理想方法。然而，对于气相采样，通常用于标准化溶剂萃取方法结果的程序并不适用：顶空（HS）组成取决于分析物固有理化性质（挥发性、极性、分配系数）和基质效应。因此，方法开发、设计和结果的表达具有挑战性。本文综述了挥发性气相定量方法（内标归一化、标准添加、稳定同位素稀释分析、多次顶空提取）及其在不同应用中的适用性。由于分析物具有信息作用，本文还讨论了不同的结果表示方式（归一化色谱面积、归一化色谱面积百分比和绝对浓度），并通过菊苣中的质量标志物、烘焙咖啡中的工艺污染物（呋喃和 2-甲基呋喃）以及优质可可中的关键香气化合物的实例进行了批判性评估。
