title: Comprehensive evaluation of direct injection mass spectrometry for the quantitative profiling of volatiles in food samples.
abstract: 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'.
authors.affiliation: Instituto de Química-Física 'Rocasolano' (CSIC), Serrano 119, 28006 Madrid, Spain.
authors.forename: R
authors.identifier: http://orcid.org/0000-0001-6103-6814
authors.initials: R
authors.lastname: Lebrón-Aguilar
authors.affiliation: Instituto de Química Orgánica General (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain.
authors.forename: A C
authors.identifier: http://orcid.org/0000-0001-8045-3883
authors.initials: AC
authors.lastname: Soria
authors.affiliation: Instituto de Química-Física 'Rocasolano' (CSIC), Serrano 119, 28006 Madrid, Spain je.quintanilla@iqfr.csic.es.
authors.forename: J E
authors.identifier: http://orcid.org/0000-0003-1863-7408
authors.initials: JE
authors.lastname: Quintanilla-López
mesh_terms: D005504:Food Analysis / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D007267:Injections; D015999:Multivariate Analysis; D012044:Regression Analysis; D013696:Temperature; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000737:chemistry
chemical_list: D055549:Volatile Organic Compounds
keywords: Thymus zygis subsp. zygis; direct injection mass spectrometry; mass spectral fingerprints; multivariate regression; quantitation; volatiles