The possibility of distinguishing between o-xylene, m-xylene, p-xylene and ethylbenzene on the basis of only their 70 eV electron ionization (EI) mass spectra has been investigated. These four isomers were distinguished by principal component analysis of respective EI mass spectra (recorded under identical conditions). The mass spectra considered contained either eleven or five m/z values, which had intensities greater than 5% or 10% of base peak, respectively.
McLaffertyF.W.StaufferD.A.LohS.Y.WesdemiotisC., “Unknown identification using reference mass spectra. Quality evaluation of databases”, J. Am. Soc. Mass Spectrom.10, 1229 (1999). doi: 10.1016/S1044-0305(99)00104-X
2.
GrubbH.M.MeyersonS., “Spectra of Alkylbenzenes”, in Mass Spectrometry of Organic Ions, Ed by McLaffertyF.W., Academic Press, New York, USA, p. 453 (1963).
3.
MoraesL.A.B.SabinoA.A.MeurerE.C.EberlinM.N., “Absolute configuration assignment of ortho, meta, or para isomers by mass spectrometry”, J. Am. Soc. Mass Spectrom.16, 431 (2005). doi: 10.1016/j.jasms.2004.12.001
4.
WuH.F.WuW.F., “Comparing differentiation of xylene isomers by electronic ionization, chemical ionization and self-ion/molecule reactions and the first observation of methyne addition ions for xylene isomers in self-ion/molecule reactions for non-nitrogenated compounds”, Rapid Commun. Mass Spectrom.17, 2399 (2003). doi: 10.1002/rcm.1203
5.
YangC.H.KhanN.A.WuH.F., “Differentiation and quantification of xylene isomers by combining headspace solid-phase microextraction/gas chromatography and self-ion molecule reaction in an ion trap tandem mass spectrometry”, J. Sep. Sci.31, 3050 (2008). doi: 10.1002/jssc.200800106
6.
BjarnasonA.TaylorJ.W.KinsingerJ.A.CodyR.B.WeilD.A., “Isomer discrimination of disubstituted benzene derivatives through gas-phase iron(I) ion reactions in a Fourier-transform mass spectrometer”, Anal. Chem.61, 1889 (1989). doi: 10.1021/ac00192a022
7.
BjarnasonA., “Xylene isomer mass spectral identification through metal ion chemistry in an FTICR”, Anal. Chem.68, 3882 (1996). doi: 10.1021/ac960597u
8.
HarrisonA.G.TongH.Y., “Characterization of C8H10 alkylbenzenes by negative ion mass spectrometry”, Org. Mass Spectrom.23, 135 (1988). doi: 10.1002/oms.1210230212
9.
MukhtarE.S.GriffithsI.W.HarrisF.M.BeynonJ.H., “Photodissociation of xylene ions: Translational energy release as a function of photon energy”, Org. Mass Spectrom.16, 51 (1981). doi: 10.1002/oms.1210160115
10.
CurtisJ.M.BoydR.K.ShushanB.MorganT.G.BeynonJ.H., “Experimental investigation of the molecular ions of the xylenes”, Org. Mass Spectrom.19, 207 (1984). doi: 10.1002/oms.1210190502
11.
KingstonE.E.BeynonJ.H.AstT.FlammangR.MaquestiauA., “Applications of charge stripping/charge exchange spectra of organic ions”, Org. Mass Spectrom.20, 546 (1985). doi: 10.1002/oms.1210200904
12.
JolliffeI.T., Principal Component Analysis.Springer, New York (2002).
13.
JacksonJ.E., A User's Guide To Principal Component.John Wiley & Sons Inc., New York USA (1991). doi: 10.1002/0471725331
14.
EsbensenK.H., Multivariate Data Analysis–in Practice. An Introduction to Multivariate Data Analysis and Experimental Design.CAMO, Oslo, Norway (2001).
15.
HejaziL.EbrahimiD.GuilhausM.HibbertD.B.“Discrimination among geometrical isomers of α-linolenic acid methyl ester using low energy electron ionization mass spectrometry”, J. Am. Soc. Mass Spectrom.20, 1272 (2009). doi: 10.1016/j.jasms.2009.02.027
