Penning ionization-FT-ICR: Application to diesel fuel analysis

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Contents lists available at ScienceDirect

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Penning ionization-FT-ICR: Application to diesel fuel analysis

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Clotilde Le Vot a , Carlos Afonso b,∗ , Claude Beaugrand c , Jean-Claude Tabet a a

Institut Parisien de Chimie Moléculaire, CNRS UMR 7201, Université Pierre et Marie Curie-Paris 6, 4 place Jussieu, 75252 Paris Cedex 05, France Normandie Univ, COBRA, UMR 6014 and FR 3038; Univ Rouen; INSA Rouen; CNRS, 1 rue Tesnière, 76821 Mont-Saint-Aignan Cedex, France c Alpha-Mos, 20 Avenue Didier Daurat, 31400 Toulouse, France

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b

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a r t i c l e

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a b s t r a c t

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Article history: Received 2 December 2013 Received in revised form 28 April 2014 Accepted 6 May 2014 Available online xxx

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Keywords: Penning ionization FT-ICR Diesel fuel Metastable

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1. Introduction

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The Penning ionization (PeI) source uses atoms of rare gases or molecules (N2 ) excited to give a flux of metastable atoms or molecules (A*) able by collision to ionize a target molecule (M) on the condition that the process is exothermic (i.e., IE(M) < EE(A)). As electron ionization, PeI allows the ionization of apolar species such as saturated hydrocarbons yielding molecular ions. In this work we present the application of vacuum PeI source coupled with a FT-ICR instrument for the characterization of a diesel fuel. Argon and krypton, as metastable gas, allow reducing significantly the fragmentation extent compared to electron ionization. Unlike with an atmospheric pressure source, the use of a vacuum source allows a good control of the ionization conditions with the absence of oxygen or other reactant such as water. © 2014 Published by Elsevier B.V.

The use of mass-spectrometry for the analysis of petroleum compounds has been the subject of recent reports [1,2]. The group of Marshall showed in particular the interest of the ultra-high resolving power of the FT-ICR for the analysis of crude oil or other highly complex mixtures [3–6]. The ultra-high mass resolving power and mass accuracy of the FT-ICR allows to separate each isobaric ion and to determine their elemental composition. In addition, FT-ICR method allows fast analysis through determination of heteroatom class, double bound equivalent and carbon atom number without chromatographic separation. Knowledge of the amount of heteroatom containing compounds is of particular importance owing to the current international regulations [7]. Crude oil distillation isolates saturated and aromatic hydrocarbons as a function of their boiling point. Petroleum-derived diesel fuel is typically the fraction that boils between 200 and 400 ◦ C (at atmospheric pressure) constituted by about 75% saturated hydrocarbons, and 25% aromatic hydrocarbons [8]. The typical carbon atom number for common diesel fuel is between 10 and 22 [9]. Compounds present in diesel fuel, are therefore are mainly apolar species. Soft atmospheric ionization techniques such as electrospray (ESI) or atmospheric pressure chemical ionization (APCI) yield mainly to the ionization of the most polar compounds yielding

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∗ Corresponding author. Tel.: +33 2 35 52 29 40. E-mail addresses: [email protected], [email protected] (C. Afonso).

significant ionization discrimination [8]. The characterization of these species is however important owing in particular to their role in environment [7]. Positive ion mode ESI yields mainly to the ionization of basic nitrogen-containing species (i.e., pyridine homologues) [8,10]. In the same way, negative ESI mode leads to the detection of acidic species [11,12]. APCI however allows the ionization of more apolar compounds especially with the presence of aprotic solvents such as toluene or isooctane [13,14]. Although very useful, these soft ionization methods do not provide an overall representation of the different compound families present in a mixture. The development of ionization source that can ionize efficiently apolar compounds such as saturated hydrocarbons is still the subject of several investigations [15–23]. To overcome this problem low-energy electron ionization (EI)FT-ICR (10–20 eV) has been used successfully [4,24]. Such EI conditions allow limiting fragmentations, but this is at the expense of sensitivity and reproducibility [5,25]. Field ionization (FI) and field desorption (FD) were also used for the analysis of petroleum compounds [21]. Atmospheric pressure photoionization (APPI) has been shown to allow ionization of various species not observed in ESI such as polycyclic aromatic hydrocarbons (PAHs) or furans [26]. However, APPI tends to produce competitively both M+• and MH+ molecular species (i.e., molecular ions and protonated molecules, respectively), which complicate the mass spectra. A hybrid quadrupole-FT-ICR equipped with an electrospray source has been recently coupled, in our laboratory, with a Penning ionization source (PeI) [27]. Penning ionization [28] was introduced in 1927 and was reconsidered more recently (as the metastable atom bombardment source, MAB) by the group of Bertrand [29]. It was

http://dx.doi.org/10.1016/j.ijms.2014.05.002 1387-3806/© 2014 Published by Elsevier B.V.

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Table 1 Excitation energy values of gases in their metastable state (eV). IE(A)b

2.1. Chemicals

Helium Argon Krypton Nitrogen Xenon

19.82 11.55 9.92 8.52 8.32

24.59 15.76 14.00 15.58 12.13

High purity gases (AlphagazTM ): krypton and argon have been purchased from Air Liquide (Nanterre, France). All chemicals have been purchased from Aldrich (Saint Quentin Fallavier, France).

Excitation energy with long lifetime [40]. Ionization energy [34].

2.2. Sample preparation

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successfully coupled to various instruments such as sector and time of flight instruments [30–32]. Penning ionization uses a quantized energy for ionization and it allows to control the available energy in 8–20 eV range. PeI includes therefore all energy ranges found in conventional ionization sources such EI, and FD/FI. It allows a control of the fragmentations and can allow selective ionization by use of different rare gases or nitrogen characterized by different excitation energy levels. Helium yields relatively high internal energy deposition and results are very close to 70 eV electron ionization (Table 1). Argon or krypton is characterized by lower excitation energy and yields to fragmentations close to FI. High ionization efficiency, such as EI, can be obtained with PeI but this depends on various parameters such as gas flow and discharge current [27]. The PeI source uses excited atoms of rare gases or excited molecules (N2 ) to give a flux of metastable neutrals (A*) able by collision to ionize a target molecule (M) on the condition that the process is exothermic (i.e., IE(M) < EE(A)), Eq. (1).

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A ∗ +M → A + M+ • + e−

(1)

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Eint (M+ • ) = EE(A) − IE(M) − KE(e− )

(2)

75 76 77 78 79 80 81 82 83 84 85 86 87 88

92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122

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EE(Am )a

a

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2. Methods

Eint (M+• ): internal energy transferred to the molecular ion; EE(A): excitation energy of metastable atoms or molecules; IE(M): ionization energy of molecule M; and KE(e− ): kinetic energy of ejected electron. The molecular ion internal energy (Eq. (2)) depends on the molecule ionization energy (IE) and on the excitation energy (EE) of the gas metastable state (Table 1). Thus, by the choice of the gas, the rate constant of fragmentations can be relatively well controlled with an energy maximum of Eint max (M+• ) = EE(A) − IE(M). Recently, commercial atmospheric pressure ionization sources related to Penning ionization (such as direct analysis in real time, DART) have demonstrated their interest for ionization of compounds with low polarity [22,33]. Although these sources are efficient and flexible, they operate at atmospheric pressure, which imply a limited control of the ionization conditions. In the present work the use of a vacuum PeI source presents several advantages. First, it allows avoiding side reactions with species present in air such as O2 or water that may lead to the formation of protonated or oxidized compounds [18]. Second, the production of the metastable atoms is carried out externally which allow deflecting all ionic species such as He+• . In fact, if this ionic species are not removed from the metastable atom flux, charge exchange processes may take place together with Penning ionization [27]. In this work, we were interested in demonstrating the interest of the Penning ionization/FT-ICR coupling for complex hydrocarbon mixture analysis. Argon and krypton were used for Penning ionization and the results were compared to electron ionization. The coupling with the FT-ICR instrument allows efficient identification of species present in complex mixtures such as diesel fuel. This is easily performed by the separation of different isobaric ions and attribution of unique elemental composition.

300 ␮L of commercial diesel fuel was dissolved with 200 ␮L of chloroform. 2 ␮L of this solution was deposited on a quartz tube and introduced in the EI/PeI source using a direct introduction probe. During acquisition the probe was heated from ambient temperature to 400 ◦ C with a gradient of 1 ◦ C/s. 2.3. Mass spectrometry Experiments were conducted on a modified hybrid Qh-FT-ICR instrument (Bruker ApexQe, Bremen, Germany) equipped with an actively shielded 7 T superconducting magnet that was combined with a homemade EI/PeI source. The latter was composed of a modified Nermag EI source bloc and a MAB gun (Dephy technology). A Varian turbomolecular pump was used to obtain a vacuum of 10−5 mbar in the source housing. These conditions do not produce even-electron molecular species. Consequently, the observed evenelectron species can be attributed exclusively to fragment ions. Details of the instrumental setup have been published elsewhere [27]. Energy levels of used gases are: Kr (9.92 eV), and Ar (11.55 eV). All mass spectra were acquired in the broadband mode from m/z 100 to m/z 1000. The image signal was amplified and digitized using 1 M data point resulting in the recording of a 0.48 s time domain signal, which was transformed into the corresponding frequency domain by Fourier transform (one zero fill and Sine-bell apodization). Under these conditions the resolving power obtained was between 400,000 (m/z 100) and 140,000 (m/z 250). The used resolving powers are enough to distinguish isobaric ions containing (or not) sulfur atom. Perfluorotributylamine (FC43) was used for external mass calibration yielding typically less than 2 ppm m/z measurement error. After mass spectrum acquisition, internal calibration was performed from confidently assigned signals allowing to obtain better than 200 pbb along the m/z range of interest. All mass spectra have been background subtracted. The background mass spectra were defined from the means of the TIC last scans. Determination of elemental composition of each signal was carried out using DataAnalysis 4.0 software. All elemental compositions containing up to 2 N, 4 O, 2 S and 1 13 C have been considered. The maximum error tolerance was 0.5 ppm. By this way a unique elemental composition was attributed for each signal. Manual filtering was however required in the few cases that yielded more than one possibility. All signals corresponding to species containing 13 C have been removed from the peak list. Type (Z), corresponding to the hydrogen deficiency relative to alkanes was determined from the Cn H2n+z X, equation in which X denotes heteroatoms. 3. Results and discussion Experiments have been conducted with a commercial diesel fuel that is expected to present mainly hydrocarbons with also limited amount of species presenting heteroatoms such as sulfur, nitrogen and oxygen. Fig. 1 presents the PeI mass spectra recorded from this diesel fuel recorded under EI, PeI(Ar) and PeI(Kr) conditions. After internal mass calibration, mass accuracy on the m/z ratio range of interest is generally better than 200 ppb.

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Fig. 1. Mass spectra of diesel fuel recorded using different ionization modes (a) EI (70 eV), (b) PeI(Ar) (EE: 11.55 eV) and (c) PeI(Kr) (EE: 9.92 eV). Enlargements of the m/z 278–296 range are presented in inset.

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It can be observed that PeI(Ar), compared to EI, yielded to the ionization of species with higher mass. Interestingly in the EI mass spectrum, the m/z values of the most intense signals present odd m/z values. In principle, molecular ions of organic molecules that do not present any nitrogen atom should have an even nominal mass (nitrogen rule). In this case the majority of the species are

expected to not present nitrogen atoms, therefore, these odd m/z ions should be mainly fragment ions. It is not expected indeed, that the main signals correspond to species presenting nitrogen atoms, unlike with ESI [8]. Elemental composition was determined for all detected ions, which confirmed this interpretation. For instance the base peak m/z 195.11684 ion in Fig. 1a is attributed to C15 H15 +

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high mass ions is very low compared to PeI(Ar). This is most likely due to the non-ionization of species characterized by ionization energy higher than the excitation energy of krypton. This result illustrates the ability of the PeI source to perform selective ionization for reduction of chemical background in the mass spectra. For that, a gas whose metastable state energy is slightly higher than the ionization energy of the molecule must be chosen in order to ionize only the molecules of interest. Under these conditions, the concept of selective ionization presents obvious analytical advantages, especially to simplify mass spectra. Overall these experimental results are consistent with the respective excitation energy of the metastable gases and illustrated the capability of the PeI source to control fragmentations using different metastable gases. As expected, the fragmentation extent follow the order EI > PeI(Ar) > PeI(Kr). In the EI and PeI spectra, the amount of species presenting heteroatoms was fairly low although it was well representative of their real amount in the diesel fuel. It can be seen that the sensitivity obtain in PeI is comparable to that obtain in electron ionization (Fig. 1). Fig. 3 presents the distribution of carbon numbers of different species detected in EI, PeI(Ar) and PeI(Kr). Distribution of the detected species indicates that the majority of the ion species present in the mass spectra present a number of carbon atoms comprise between 12 and 27. It should be noted that the detection of ions above m/z 200 is favored in our instrument because of lower transmission and lower trapping efficiency (in the external linear ion trap) of the low m/z ions. In a relative point of view this histogram show clearly the presence of a higher amount of low molecular weight ions in the EI mass spectrum. In the other hand, the relative abundance of large species is significantly higher in PeI(Ar). In fact compared to PeI(Kr), the results with PeI(Ar) yielded the higher amount of large species. Kr yielded the lower amount of fragmentations but yielded also a lower ionization efficiency owing to its low excitation energy. In practice mainly species of low ionization energy can be ionized with excited krypton, corresponding therefore to polyunsaturated species. Fig. 2. Enlargements of the m/z 209 ± 0.5 and m/z 210 ± 0.5 range for mass spectra recorded in the (a) EI, (b) PeI(Ar) (EE: 11.55 eV) and (c) PeI(Kr) (EE: 9.92 eV) modes.

192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217

(theoretical m/z 195.11683, 51 ppb error). The enlargement presented in Fig. 2a illustrates this behavior for the m/z 209 and m/z 210 ions. The larger signal is the even electron m/z 209.13247 ion attributed to C16 H17 + and a nitrogen containing species can be detected at m/z 209.11986 (C15 H15 N1 +• ) but in a very low abundance. Reversely, in the PeI(Ar) spectrum (Fig. 2b) the main ion distribution present even m/z values which indicates that the fragmentation extent is lower than in EI. The presence of a higher amount of high mass species is also consistent with this interpretation. Argon presents excitation energy of 11.55 eV therefore species with the C16 H18 which are expected to have a ionization between 8.0 and 8.5 eV [34] will yield a maximum internal energy excess between 3.0 and 3.5 eV. This should be compared to the ion internal energy distribution obtain under 70 eV EI conditions that is in average 5.5 eV with a maximum of 15–16 eV [35]. With Penning ionization, the maximum ion internal energy will be the difference between the metastable gas excitation energy and the ionization energy of the considered molecule (Eq. (2)). In Fig. 2b it can be observed that the relative abundance of even electron species are significantly reduced compared to electron ionization. Krypton presents a low excitation energy (9.92 eV), which is translated in the mass spectrum of diesel fuel in the detection of mainly molecular ions (e.g., C16 H18 +• ). Even if some fragment ions can still be detected, their relative abundance are considerably reduced. However, it can be observed also that the abundance of

3.1. Kendrick plots

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The complexity of the mass spectra implies the use of mathematical treatment to facilitate the visualization of the high amount of information present. Marshall and co-workers proposed the use of Kendrick plots in order to display the data present in the mass spectra in a 2D diagram [6,36,37]. The aim is to determine homologous series of compounds, according to the Kendrick mass defect. The mass defect is characteristic of a homologous series, which is determined by the DBE and heteroatom class, but is independent of carbon number. In the case of hydrocarbons, species of the same class are characterized by elemental compositions that differ only by the number of CH2 . By this way, the Kendrick mass and Kendrick mass defect as defined in Eqs. (3) and (4) allow to remove the mass defect of CH2 . Kendrick Mass = IUPAC Mass ×

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KMD = Kendrick Nominal Mass − Kendrick Mass

256 257 258 259 260 261 262 263 264 265 266 267

(3)

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(4)

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Fig. 4 presents the Kendrick plot of diesel fuel recorded in EI mode displaying compounds as a function of the heteroatom content, class and type (Fig. 4a) and as a function of ion relative intensity (Fig. 4b). The Kendrick diagram allows to easily differentiate the different molecule families and also to remove meaningless data such as noise peaks as they will not be aligned with other series. One of the main disadvantages of EI is the large amount of fragment ions (mainly even-electron species). As discussed above, the parity of the molecular ions m/z values is an indication of the

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Fig. 3. Distribution of the carbon atom number of the species detected in diesel fuel using EI, PeI(Ar) and PeI(Kr).

Fig. 4. Kendrick plot of diesel fuel recorded in EI mode (a) displaying compounds as a function of the heteroatom content, class and type and (b) as a function of ion relative abundance.

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Fig. 5. Kendrick plot of diesel fuel recorded in PeI(Ar) mode (a) displaying compounds as a function of the heteroatom content, class and type and (b) as a function of ion relative abundance.

Table 2 Relative abundance of odd- and even- m/z species.

EI PeI(Ar) PeI(Kr)

279 280 281 282 283 284 285 286 287 288 289 290 291

Odd m/z

Even m/z

60.8 39.9 25.3

39.2 60.1 74.7

ion type. The majority of the species that do not present any nitrogen atom (or presenting an even number of nitrogen) with an even m/z are necessarily intact species. In the same way, the majority of ions with odd m/z value are fragment ions. This is only fairly accurate, as some fragment ions such as those produced through rearrangement should present even m/z value. Based on this consideration it was possible to estimate that the relative amount of fragment ions is 60.8% in the EI mass spectrum (Table 2). The Kendrick diagram obtained from PeI(Ar) mass spectrum displays species up to m/z 370 corresponding to those containing more than 23 carbon atoms (Fig. 5). This distribution is slightly higher than expected but this is due to the non-optimization of our instrument optics for transmission of low

m/z ions [5]. With PeI(Ar), the relative amount of fragment ions is 39.9%. The majority of the detected ions are therefore, in this case, intact species. The Kendrick plot allows to readily evidence specific compound class such as sulfur containing species. In processed diesel fuels such species are expected to be present in very low amount owing to the regulations concerning the sulfur content in gasoline and diesel fuel [23,38]. In the EI mass spectrum, the main ion presenting a sulfur atom is detected at m/z 211.05754 corresponding to the C14 H11 S1 elemental composition. This corresponds most likely to a radical hydrogen loss from the molecular ion of 4,6-dimethyl dibenzothiophene that is known to resist the hydrodesulfurization process [7]. Its trimethylated homologous form can be also present and detected for the same reason: a steric effect which hinders the catalytic reduction. This hypothesis is confirmed by the presence of the m/z 212.06536 (C14 H12 S1 ) and m/z 226.08111 (C15 H14 S1 ) ions which are the main sulfur containing species in the PeI(Ar) mass spectrum. This behavior is consistent with fragmentation pathways of dibenzothiophene derivatives [39]. Finally, the same diesel fuel sample was analyzed under positive ESI and APCI mode. Fig. 6 presents the species detected using the

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References

Fig. 6. Normalized intensity for each compound class produced under ESI, APCI, EI and Penning Ionization.

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different ionization modes as a function of the compound class. As it was already shown previously, almost exclusively nitrogen containing species have been detected with positive ion mode ESI [8]. By contrast, the APCI spectra displayed more complex mass spectra yielding to the production of abundant species presenting O, N, and S heteroatoms. In particular, the fast determination of O containing compounds particularly interesting for the analysis of biodiesels whereas the relative abundance of S containing species can be controlled even if they are present in low abundance. This result enlightens the advantage of Penning ionization that yields to less ionization discrimination compared to atmospheric pressure ion sources. 4. Conclusion The coupling between a Penning ionization source and a FT-ICR presents many advantages for the analysis of petroleum distillates. Indeed, the possibility of using different metastable gases having a low excitation energy (e.g., Kr), allows to limit fragmentations and to hinder the interfering compounds by selective ionization. Thus, the identification of the various compounds present in the mixture is simplified. The ultra-high resolution of the FT-ICR instrument allows to measure accurate m/z ratios (deviations < 1 ppm) of ions and to distinguish the isobaric ions by their elemental composition. The properties of PeI source are consistent with the respective excitation energy of the metastable gases and illustrated the capability of the PeI source to control fragmentations using different metastable gases. In APCI, the fast determination of O containing compounds particularly interesting for the analysis of biodiesels whereas the relative abundance of S containing species can be controlled even if they are present in low amount. The use of Ar and Kr metastable gas, under vacuum allows to produce mainly molecular ions. This property largely simplifies the mass spectra and thus, facilitates the detection and identification of the compounds. Acknowledgements

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DGA, CEA (NRBC Program), Université Pierre et Marie Curie 347 and CNRS are gratefully acknowledged for financial support. CA 348 acknowledges financial support by EFRD (No. 31708), Labex SynOrg 349 (ANR-11-LABX-0029) and the Région Haute Normandie (CRUNCh 350 Q4 network). The SM3 P platform and the TGE High field FT-ICR (CNRS) 351 is gratefully acknowledged for the access to the FT-ICR mass spec352 trometer. 346

[1] C.-S. Hsu, C.L. Hendrickson, R.P. Rodgers, A.M. McKenna, A.G. Marshall, Petroleomics: advanced molecular probe for petroleum heavy ends, J. Mass Spectrom. 46 (2011) 337–343. [2] K. Miyabayashi, Y. Naito, M. Miyake, Characterization of heavy oil by FT-ICR MS coupled with various ionization techniques, J. Jpn. Petrol. Inst. 52 (2009) 159–171. [3] A.G. Marshall, R.P. Rodgers, Petroleomics: chemistry of the underworld, Proc. Natl. Acad. Sci. U. S. A. 105 (2008) 18090–18095. [4] S. Guan, A.G. Marshall, S.E. Scheppele, Resolution and chemical formula identification of aromatic hydrocarbons and aromatic compounds containing sulfur, nitrogen, or oxygen in petroleum distillates and refinery streams, Anal. Chem. 68 (1996) 46–71. [5] R.P. Rodgers, F.M. White, C.L. Hendrickson, A.G. Marshall, K.V. Andersen, Resolution, elemental composition, and simultaneous monitoring by Fourier transform ion cyclotron resonance mass spectrometry of organosulfur species before and after diesel fuel processing, Anal. Chem. 70 (1998) 4743–4750. [6] C.A. Hughey, R.P. Rodgers, A.G. Marshall, Resolution of 11 000 compositionally distinct components in a single electrospray ionization Fourier transform ion cyclotron resonance mass spectrum of crude oil, Anal. Chem. 74 (2002) 4145–4149. [7] A. Stanislaus, A. Marafi, M.S. Rana, Recent advances in the science and technology of ultra low sulfur diesel (ULSD) production, Catal. Today 153 (2010) 1–68. [8] C.A. Hughey, C.L. Hendrickson, R.P. Rodgers, A.G. Marshall, Elemental composition analysis of processed and unprocessed diesel fuel by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry, Energy Fuels 15 (2001) 1186–1193. [9] J. Bacha, J. Freel, A. Gibbs, L. Gibbs, G. Hemighaus, K. Hoekman, J. Horn, A. Gibbs, M. Ingham, L. Jossens, D. Kohler, D. Lesnini, J. McGeehan, M. Nikanjam, E. Olsen, R. Organ, B. Scott, M. Sztenderowicz, A. Tiedemann, C. Walker, J. Lind, J. Jones, D. Scott, J. Mills, Diesel Fuels Technical Review, Chevron Corporation, 2007. [10] K. Qian, K.E. Edwards, J.H. Diehl, L.A. Green, Fundamentals and applications of electrospray ionization mass spectrometry for petroleum characterization, Energy Fuels 18 (2004) 1784–1791. [11] L.A. Stanford, S. Kim, R.P. Rodgers, A.G. Marshall, Characterization of compositional changes in vacuum gas oil distillation cuts by electrospray ionization Fourier transform – ion cyclotron resonance (FT-ICR) mass spectrometry, Energy Fuels 20 (2006) 1664–1673. [12] M.P. Barrow, L.A. McDonnell, X.D. Feng, J. Walker, P.J. Derrick, Determination of the nature of naphthenic acids present in crude oils using nanospray Fourier transform ion cyclotron resonance mass spectrometry: the continued battle against corrosion, Anal. Chem. 75 (2003) 860–866. [13] Y.H. Kim, S. Kim, Improved abundance sensitivity of molecular ions in positiveion APCI MS analysis of petroleum in toluene, J. Am. Soc. Mass Spectrom. 21 (2010) 386–392. [14] N. Hourani, J.T. Andersson, I. Moller, M. Amad, M. Witt, S.M. Sarathy, Atmospheric pressure chemical ionization Fourier transform ion cyclotron resonance mass spectrometry for complex thiophenic mixture analysis, Rapid Commun. Mass Spectrom. 27 (2013) 2432–2438. [15] J.L. Campbell, M.N. Fiddler, K.E. Crawford, P.P. Gqamana, H.I. Kenttaemaa, Analysis of polyethylene by using cyclopentadienyl cobalt chemical ionization combined with laser-induced acoustic desorption/Fourier transform ion cyclotron resonance mass spectrometry, Anal. Chem. 77 (2005) 4020–4026. [16] W.E. Wallace, Reactive MALDI mass spectrometry: application to high mass alkanes and polyethylene, Chem. Commun. (2007) 4525–4527. [17] K. Hiraoka, H. Furuya, S. Kambara, S. Suzuki, Y. Hashimoto, A. Takamizawa, Atmospheric-pressure Penning ionization of aliphatic hydrocarbons, Rapid Commun. Mass Spectrom. 20 (2006) 3213–3222. [18] Z. Yang, A.B. Attygalle, Aliphatic hydrocarbon spectra by helium ionization mass spectrometry (HIMS) on a modified atmospheric-pressure source designed for electrospray ionization, J. Am. Soc. Mass Spectrom. 22 (2011) 1395–1402. [19] C. Barrère, F. Maire, C. Afonso, P. Giusti, Atmospheric solid analysis probe – ion mobility mass spectrometry of polypropylene, Anal. Chem. 84 (2012) 9349–9354. [20] S.E. Scheppele, C.S. Hsu, T.D. Marriott, P.A. Benson, K.N. Detwiler, N.B. Perreira, Field-ionization relative sensitivities for the analysis of saturated hydrocarbons from fossil-energy-related materials, Int. J. Mass Spectrom. Ion Phys. 28 (1978) 335–346. [21] T.M. Schaub, R.P. Rodgers, A.G. Marshall, Speciation of aromatic compounds in petroleum refinery streams by continuous flow field desorption ionization FT-ICR mass spectrometry, Energy Fuels 19 (2005) 1566–1573. [22] R.B. Cody, Observation of molecular ions and analysis of nonpolar compounds with the direct analysis in real time ion source, Anal. Chem. 81 (2009) 1101–1107. [23] F. Maire, K. Neeson, R. Denny, M. McCullagh, C. Lange, C. Afonso, P. Giusti, Identification of ion series using ion mobility mass spectrometry: the example of alkyl-benzothiophene and alkyl-dibenzothiophene ions in diesel fuels, Anal. Chem. 85 (2013) 5530–5534. [24] C.S. Hsu, Z.M. Liang, J.E. Campana, Hydrocarbon characterization by ultrahighresolution Fourier-transform ion-cyclotron resonance mass-spectrometry, Anal. Chem. 66 (1994) 850–855.

Please cite this article in press as: C. Le Vot, et al., Int. J. Mass Spectrom. (2014), http://dx.doi.org/10.1016/j.ijms.2014.05.002

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[25] D. Severin, T. David, L. Brouwer, Determination of heteroatom combinations in middle distillates by high resolution mass spectrometry, Pet. Sci. Technol. 17 (1999) 1043–1049. [26] T.M. Schaub, C.L. Hendrickson, J.P. Quinn, R.P. Rodgers, A.G. Marshall, Instrumentation and method for ultrahigh resolution field desorption ionization Fourier transform ion cyclotron resonance mass spectrometry of nonpolar species, Anal. Chem. 77 (2005) 1317–1324. [27] C. Le Vot, C. Afonso, C. Beaugrand, J.-C. Tabet, Implementation of a Penning ionization source on a FTICR instrument with ion funnel optics, Int. J. Mass Spectrom. 306 (2011) 150–158. [28] F.M. Penning, Ionisation by metastable atoms, Naturwissenschaften 15 (1927) 818. [29] D. Faubert, A. L’Heureux, O. Peraldi, M. Mousselmal, G. Sanchez, M.J. Bertrand, Metastable atom bombardment (MAB) ionization source: design, optimization and analytical performances, Adv. Mass Spectrom. 15 (2001) 431–432. [30] J.G. Wilkes, K.L. Glover, M. Holcomb, F. Rafii, X.X. Cao, J.B. Sutherland, S.A. McCarthy, S. Letarte, M.J. Bertrand, Defining and using microbial spectral databases, J. Am. Soc. Mass Spectrom. 13 (2002) 875–887. [31] M. Boutin, J. Lesage, C. Ostiguy, M.J. Bertrand, Comparison of EI and metastable atom bombardment ionization for the identification of polyurethane thermal degradation products, J. Anal. Appl. Pyrolysis 70 (2003) 505–517.

[32] S. Letarte, D. Morency, J. Wilkes, M.J. Bertrand, Py-MAB-Tof detection and identification of microorganisms in urine, J. Anal. Appl. Pyrolysis 71 (2004) 13–25. [33] R.B. Cody, A.J. Dane, Soft ionization of saturated hydrocarbons, alcohols and nonpolar compounds by negative-ion direct analysis in real-time mass spectrometry, J. Am. Soc. Mass Spectrom. (2013). [34] P.J. Linstrom, W.G. Mallard (Eds.), NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg, MD, 2005 http://webbook.nist.gov [35] K. Vekey, Internal energy effects in mass spectrometry, J. Mass Spectrom. 31 (1996) 445–463. [36] C.A. Hughey, C.L. Hendrickson, R.P. Rodgers, A.G. Marshall, K. Qian, Kendrick mass defect spectrum: A compact visual analysis for ultrahigh-resolution broadband mass spectra, Anal. Chem. 73 (2001) 4676–4681. [37] E. Kendrick, A mass scale based on CH2 = 14.0000 for high resolution mass spectrometry of organic compounds, Anal. Chem. 35 (1963) 2146–2154. [38] B. Pawelec, R.M. Navarro, J.M. Campos-Martin, J.L.G. Fierro, Towards near zerosulfur liquid fuels: a perspective review, Catal. Sci. Technol. 1 (2011) 23–42. [39] L.C. Herrera, L. Ramaley, J.S. Grossert, Fragmentation pathways of some benzothiophene radical cations formed by atmospheric pressure chemical ionisation, Rapid Commun. Mass Spectrom. 23 (2009) 571–579. [40] P.E. Siska, Molecular beam studies of penning ionization, Rev. Modern Phys. 65 (1993) 337–412.

Please cite this article in press as: C. Le Vot, et al., Int. J. Mass Spectrom. (2014), http://dx.doi.org/10.1016/j.ijms.2014.05.002

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