Of the ionic liquid 1-butyl-3-methylimidazolium (C+) tricyanomethide (A−) high-mass cluster ions of both positive ([CnAn–1]+) and negative ([Cn–1An]−) charge were generated and detected by direct analysis in real time (DART) Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS). After optimization of the settings of the DART ionization source and of the mass analyser, ions of m/z values unprecedented in DART-MS were detected. Thus, the upper m/z limits of positive-ion and negative-ion DART-MS were substantially expanded. Negative-ion DART-MS delivered cluster ions up to [C15A16]−, m/z 3527 (nominal mass of monoisotopic ion), while positive-ion DART-MS even yielded ions up to [C30A29]+, m/z 6784. The identification of the cluster ions is supported by their accurate mass and exact mass differences corresponding to CA between adjacent cluster ion peaks.
CodyR.B.LarameeJ.A.DurstH.D., “Versatile new ion source for the analysis of materials in open air under ambient conditions”, Anal. Chem.77, 2297 (2005). doi: http://dx.doi.org/10.1021/ac050162j
WestonD.J., “Ambient ionization mass spectrometry: Current understanding of mechanistic theory; analytical performance and application areas”, Analyst135, 661 (2010). doi: http://dx.doi.org/10.1039/b925579f
4.
GreenF.M.SalterT.L.StokesP.GilmoreI.S.O'ConnorG., “Ambient mass spectrometry: Advances and applications in forensics”, Surf. Interface Anal.42, 347 (2010). doi: http://dx.doi.org/10.1002/sia.3131
5.
ChernetsovaE.S.MorlockG.E., “Determination of drugs and drug-like compounds in different samples with direct analysis in real time mass spectrometry”, Mass Spectrom. Rev.30, 875 (2011). doi: http://dx.doi.org/10.1002/mas.20304
HajslovaJ.CajkaT.VaclavikL., “Challenging applications offered by direct analysis in real time (DART) in food-quality and safety analysis”, Trends Anal. Chem.30, 204 (2011). doi: http://dx.doi.org/10.1016/j.trac.2010.11.001
8.
CodyR.B., “What is the opposite of Pandora's box? Direct analysis, ambient ionization, and a new generation of atmospheric pressure ion sources”, Mass Spectrom.2, S0007 (2013). doi: http://dx.doi.org/10.5702/massspectrometry.S0007
GrossJ.H., “Analysis of silicones released from household items and baby articles by direct analysis in real time-mass spectrometry”, J. Am. Soc. Mass Spectrom.26, 511 (2015). doi: http://dx.doi.org/10.1007/s13361-014-1042-5
11.
GrossJ.H., “Polydimethylsiloxane extraction from silicone rubber into baked goods detected by direct analysis in real time mass spectrometry”, Eur. J. Mass Spectrom.21, 313 (2015). doi: http://dx.doi.org/10.1255/ejms.1333
12.
GrossJ.H., “Direct analysis in real time mass spectrometry and its application for the analysis of polydimethyl-siloxanes”, Spectrosc. Eur.27, 6 (2015).
13.
GrossJ.H., “Polydimethylsiloxane-based wide range mass calibration for direct analysis in real time mass spectrometry”, Anal. Bioanal. Chem.405, 8663 (2013). doi: http://dx.doi.org/10.1007/s00216-013-7287-1
14.
MazzottaM.G.PaceR.B.WallgrenB.N.MortonS.A.IIIMillerK.M.SmithD.L., “Direct analysis in real time mass spectrometry (DART-MS) of ionic liquids”, J. Am. Soc. Mass Spectrom.24, 1616 (2013). doi: http://dx.doi.org/10.1007/s13361-013-0696-8
15.
SogaT.KakazuY.RobertM.TomitaM.NishiokaT., “Qualitative and quantitative analysis of amino acids by capillary electrophoresis-electrospray ionizationtandem mass spectrometry”, Electrophoresis25, 1964 (2004). doi: http://dx.doi.org/10.1002/elps.200305791
16.
SchugK.LindnerW., “Development of a screening technique for noncovalent complex formation between guanidinium- and phosphonate-functionalized amino acids by electrospray ionization ion trap mass spectrometry: Assessing ionization and functional group interaction”, Int. J. Mass Spectrom.235, 213 (2004). doi: http://dx.doi.org/10.1016/j.ijms.2004.04.012
17.
LouX.van DongenJ.L.J.MeijerE.W., “Generation of CsI cluster ions for mass calibration in matrix-assisted laser desorption/ionization mass spectrometry”, J. Am. Soc. Mass Spectrom.21, 1223 (2010). doi: http://dx.doi.org/10.1016/j.jasms.2010.02.029
18.
GrossJ.H., “High-mass cluster ions of ionic liquids in positive-ion and negative-ion DART-MS and their application for wide range mass calibrations”, Anal. Bioanal. Chem.406, 2853 (2014). doi: http://dx.doi.org/10.1007/s00216-014-7720-0
19.
GrossJ.H., “Wide range mass calibration for negative-ion direct analysis in real time-mass spectrometry”, Eur. J. Mass Spectrom.20, 155 (2014). doi: http://dx.doi.org/10.1255/ejms.1266
20.
PerezJ.J.HarrisG.A.ChipukJ.E.BrodbeltJ.S.GreenM.D.HamptonC.Y.FernandezF.M., “Transmission-mode direct analysis in real time and desorption electrospray ionization mass spectrometry of insecticide-treated bednets for malaria control”, Analyst135, 712 (2010). doi: http://dx.doi.org/10.1039/b924533b
21.
KrechmerJ.TiceJ.CrawfordE.MusselmanB., “Increasing the rate of sample vaporization in an open air desorption ionization source by using a heated metal screen as a sample holder”, Rapid Commun. Mass Spectrom.25, 2384 (2011). doi: http://dx.doi.org/10.1002/rcm.5133
22.
ChernetsovaE.S.CrawfordE.A.ShikovA.N.PozharitskayaO.N.MakarovV.G.MorlockG.E., “ID-CUBE direct analysis in real time high-resolution mass spectrometry and its capabilities in the identification of phenolic components from the green leaves of Bergenia crassifolia L”, Rapid Commun. Mass Spectrom.26, 1329 (2012). doi: http://dx.doi.org/10.1002/rcm.6226
