Quantitative analysis of essential oils: a complex task

This article provides a critical overview of current methods to quantify essential oil components. The fields of application and limits of the most popular approaches, in particular relative percentage abundance, normalized percentage abundance, concentration and true amount determination via calibration curves, are discussed in detail. A specific paragraph is dedicated to the correct use of the most widely used detectors and to analyte response factors. A set of applications for each approach is also included to illustrate the considerations. Copyright (C) 2008 John Wiley & Sons, Ltd.