Profiling of volatile substances by direct thermal desorption gas chromatography high-resolution mass spectrometry for flagging a characterising flavour in cigarette tobacco

This paper describes an analytical method that supports the implementation of articles 9 and 10 of the WHO Framework Convention on Tobacco Control (FCTC) regarding the provisions on the reduction of the palatability and attractiveness of tobacco products regarding flavour ingredients. This study aimed to develop a screening method to identify cigarettes that may have a characterising flavour to support the implementation of the ban of characterising flavours of tobacco products, as laid down in the US and EU law. An analytical method combining direct thermal desorption and GC–QTOF MS was developed for acquiring the profile of volatile and semi-volatile substances in tobacco. A database of flavour additives was created comprising 133 compounds. A group of cigarettes without a declared characterising flavour was used to establish a reference profile of flavouring chemicals commonly present in tobacco products. A reference profile was modelled both by the means of principal component analysis (PCA) and based on the calculation of threshold values specified as 95th percentile of measured compounds’ relative responses. Cigarettes and roll-your-own tobacco labelled as flavoured were analysed to evaluate the discrimination power of the method. A constructed model of the reference cigarettes allowed the differentiation of the flavoured tobacco products from the reference group. The method allows drawing conclusions on the chemical profiles of flavour constituents of tobacco products at even sensorial subliminal concentration levels and is suitable for both the initial screening of products on the market for characterising flavours and for confirmatory purposes after sensory analysis. Graphical abstract

Direct thermal desorption gas chromatographic determination of toxicologically relevant concentrations of ethylene glycol in whole blood

A simple and rapid method involving thermal desorption gas chromatography (TD-GC) with flame ionisation detection has been successfully developed for the determination of ethylene glycol in whole blood.

Comprehensive evaluation of direct injection mass spectrometry for the quantitative profiling of volatiles in food samples

Although qualitative strategies based on direct injection mass spectrometry (DIMS) have recently emerged as an alternative for the rapid classification of food samples, the potential of these approaches in quantitative tasks has scarcely been addressed to date. In this paper, the applicability of different multivariate regression procedures to data collected by DIMS from simulated mixtures has been evaluated. The most relevant factors affecting quantitation, such as random noise, the number of calibration samples, type of validation, mixture complexity and similarity of mass spectra, were also considered and comprehensively discussed. Based on the conclusions drawn from simulated data, and as an example of application, experimental mass spectral fingerprints collected by direct thermal desorption coupled to mass spectrometry were used for the quantitation of major volatiles in Thymus zygis subsp. zygis chemotypes. The results obtained, validated with the direct thermal desorption coupled to gas chromatography–mass spectrometry method here used as a reference, show the potential of DIMS approaches for the fast and precise quantitative profiling of volatiles in foods. This article is part of the themed issue ‘Quantitative mass spectrometry’.