TY - JOUR AB - The analysis of petrochemical materials and particulate matter originating from combustion sources remains a challenging task for instrumental analytical techniques. A detailed chemical characterisation is essential for addressing health and environmental effects. Sophisticated instrumentation, such as mass spectrometry coupled with chromatographic separation, is capable of a comprehensive characterisation, but needs advanced data processing methods. In this study, we present an improved data processing routine for the mass chromatogram obtained from gas chromatography hyphenated to atmospheric pressure chemical ionisation and ultra high resolution mass spectrometry. The focus of the investigation was the primary combustion aerosol samples, i.e. particulate matter extracts, as well as the corresponding fossil fuels fed to the engine. We demonstrate that utilisation of the entire transient and chromatographic information results in advantages including minimisation of ionisation artefacts and a reliable peak assignment. A comprehensive comparison of the aerosol and the feed fuel was performed by applying intensity weighted average values, compound class distribution and principle component analysis. Certain differences between the aerosol generated with the two feed fuels, diesel fuel and heavy fuel oil, as well as between the aerosol and the feed were revealed. For the aerosol from heavy fuel oil, oxidised species from the CHN and CHS class precursors of the feed were predominant, whereas the CHOx class is predominant in the combustion aerosol from light fuel oil. Furthermore, the complexity of the aerosol increases significantly compared to the feed and incorporating a higher chemical space. Coupling of atmospheric pressure chemical ionisation to gas chromatography was found to be a useful additional approach for characterisation of a combustion aerosol, especially with an automated utilisation of the information from the ultra-high resolution mass spectrometer and the chromatographic separation. AU - Rüger, C.P.* AU - Schwemer, T.* AU - Sklorz, M. AU - O'Connor, P.B.* AU - Barrow, M.P.* AU - Zimmermann, R. C1 - 52178 C2 - 43753 SP - 28-39 TI - Comprehensive chemical comparison of fuel composition and aerosol particles emitted from a ship diesel engine by gas chromatography atmospheric pressure chemical ionisation ultra-high resolution mass spectrometry with improved data processing routines. JO - Eur. J. Mass Spectrom. VL - 23 IS - 1 PY - 2017 SN - 1469-0667 ER - TY - JOUR AB - Proton sponges are polyamines with high proton affinity that enable gentle deprotonation of even mildly acidic compounds. In this study, the concept of proton sponges as signal enhancing dopants for electrospray ionisation is presented for the first time. 1,8-Bis(dimethylamino) naphthalene (DMAN) and 1,8-bis(tetramethylguanidino) naphthalene (TMGN) were chosen as dopants, using methanol and acetonitrile/methanol as solvents. Individual standard compounds, compound mixtures and a diesel fuel as a complex sample matrix were investigated. Both proton sponges enhanced signal intensities in electrospray ionisation negative mode, but TMGN decomposed rapidly in methanolic solution. Significantly higher signals were only achieved using the acetonitrile/methanol mixture. On average a more than 10-fold higher signal intensity was measured with 10(-3) mol l(-1) DMAN concentration. A stronger signal increase of alcohol functionalities was observed compared to acid functionalities. All compound classes which were detected in the diesel fuel (CH-and CHOx-class) received roughly 100-fold higher signal intensities when using DMAN as a dopant. Furthermore, the number of detected compounds as well as the double bond equivalent of the detected compounds increased. The compound class distribution shifted when adding DMAN and the formerly dominant CHO2-, CHO3-, and CHO4-classes received similar relative intensities as formerly less accessible classes. The findings depict DMAN as a promising additive for electrospray ionisation negative analysis of at least mildly acidic compounds, even within complex sample material. AU - Wirth, M.A.* AU - Rueger, C.P.* AU - Sklorz, M. AU - Zimmermann, R. C1 - 51665 C2 - 43373 CY - London SP - 49-54 TI - Using aromatic polyamines with high proton affinity as "proton sponge'' dopants for electrospray ionisation mass spectrometry. JO - Eur. J. Mass Spectrom. VL - 23 IS - 2 PB - Sage Publications Ltd PY - 2017 SN - 1469-0667 ER - TY - JOUR AB - Arginine-vasopressin (AVP) and lysine-vasopressin (LVP) were analyzed by reversed-phase liquid chromatography/mass spectrometry (LC-MS) using Fourier-transform ion cyclotron resonance (FT-ICR) mass spectrometry (MS) electrospray ionization (ESI) in the positive ion mode. LVP and AVP exhibited the protonated adduct [M+H](+) as the predominant ion at m/z 1056.43965 and at m/z 1084.44561, respectively. Infrared multiphoton dissociation (IRMPD), using a CO2 laser source at a wavelength of 10.6μm, was applied to protonated vasopressin molecules. The IRMPD mass spectra presented abundant mass fragments essential for a complete structural information. Several fragment ions, shared between two target molecules, are discussed in detail. Some previously unpublished fragments were identified unambiguously utilizing the high resolution and accurate mass information provided by the FT-ICR mass spectrometer. The opening of the disulfide loop and the cleavage of the peptide bonds within the ring were observed even under low-energy fragmentation conditions. Coupling the high-performance FT-ICR mass spectrometer with IRMPD as a contemporary fragmentation technique proved to be very promising for the structural characterization of vasopressin. AU - Bianco, G.* AU - Battista, F.* AU - Buchicchio, A.* AU - Amarena, C.G.* AU - Schmitt-Kopplin, P. AU - Guerrieri, A.* C1 - 46645 C2 - 37649 SP - 211-219 TI - Structural characterization of arginine-vasopressin and lysine-vasopressin by Fourier-transform ion cyclotron resonance mass spectrometry and infrared multiphoton dissociation. JO - Eur. J. Mass Spectrom. VL - 21 IS - 3 PY - 2015 SN - 1469-0667 ER - TY - JOUR AB - There have been many successful efforts to enrich phosphopeptides in complex protein mixtures by the use of immobilized metal affinity chromatography (IMAC) and/or metal oxide affinity chromatography (MOAC) with which mass spectrometric analysis of phosphopeptides has become state of the art in specialized laboratories, mostly applying nanoLC electrospray ionization mass spectrometry-based investigations. However, widespread use of these powerful techniques is still not achieved. In this study, we present a ready-to-use phosphopeptide enrichment procedure using commercially available TiO(2)-loaded pipette tips in combination with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) analyses. Using α-casein as a model protein and citric acid as additive during sample loading, a similar enrichment success can be achieved as compared to applying 2,5- dihydroxy benzoic acid (DHB) for this task. But the DHB-inherited drawbacks are eliminated. In addition, we show that combining DHB and 2,4,6-trihydroxy acetophenone (THAP) as matrix for MALDI-MS measurements retains the sensitivity of DHB for phosphopeptide analysis but adds the homogenous crystallization properties of THAP, enabling preparation of evenly distributed matrix surfaces on MALDI-MS anchor targets, a prerequisite for automated MALDI- MS analyses. Tripartite motif-containing protein 28 and stathmin are two examples for which successful phosphopeptide enrichment of either sodium dodecyl sulfate polyacrylamide gel electrophoresis or two-dimensional gel electrophoresis-separated proteins is shown. Finally, high resolution MALDI Fourier transform ion cyclotron resonance mass spectrometry after phosphopeptide enrichment suggests that chemical dephosphorylation may occur as a side reaction during basic elution of phosphopeptides bound to MOAC surfaces, suggesting that proteome-wide phosphopeptide analyses ought to be interpreted with caution. In contrast, in-depth analysis of phosphopeptide/non-phosphorylated peptide siblings may be used to estimate stability differences of phosphorylation sites in individual proteins, possibly adding valuable information on biological regulation processes. AU - Eickner, T.* AU - Mikkat, S.* AU - Lorenz, P.* AU - Sklorz, M. AU - Zimmermann, R. AU - Thiesen, H.J.* AU - Glocker, M.O.* C1 - 7277 C2 - 29637 SP - 507-523 TI - Systematic studies on TiO2-based phosphopeptide enrichment procedures upon in-solution and in-gel digestions of proteins. Are there readily applicable protocols suitable for matrix-assisted laser desorption/ionization mass spectrometry-based phosphopeptide stability estimations? JO - Eur. J. Mass Spectrom. VL - 17 IS - 5 PB - IM Publications PY - 2011 SN - 1469-0667 ER - TY - JOUR AB - The formation of boron esters was investigated in peat-soluble humified materials with a detailed molecular-level description of boron-organic interactions. Thousands of individually baseline separated signals were obtained from the analysis of natural organic matter of peat samples, using Fourier transform ion cyclotron resonance mass spectrometry. This technique offers unsurpassed isotope-specific mass resolution that can lead to precise molecular formula assignments by means of mathematical data analysis and visualisation techniques, such as mass defect (Kendrick) or elemental ratio (van Krevelen) plots. The analysis of potential boron binding structures within the sample of natural organic matter was described based on prior results. Herein, we describe an algorithm that can be used to effectively distinguish and filter complexes through data obtained from boron-enriched systems with highly intricate mass spectra, such as natural organic matter. AU - Gáspár, A. AU - Lucio, M. AU - Harir, M. AU - Schmitt-Kopplin, P. C1 - 3854 C2 - 28676 SP - 113-123 TI - Targeted and non-targeted boron complex formation followed by electrospray Fourier transform ion cyclotron mass spectrometry: A novel approach for identifying boron esters with natural organic matter. JO - Eur. J. Mass Spectrom. VL - 17 IS - 2 PB - IM Publications LLP PY - 2011 SN - 1469-0667 ER - TY - JOUR AB - Here, we propose a novel computational and visual approach for the analysis of high field Fourier transform ion cyclotron resonance mass spectra (FTICR/MS) based on successive and multiple atomic and Kendrick analogous mass difference analyses. Compositional networks based on elemental compositions and functional networks based on selected functional groups equivalents enable improved assignment options of elemental composition and classification of organic complexity with tunable validation windows. The approach is demonstrated through the analysis of a 12T FTICR mass spectrum of an intricate water soluble extract of a secondary organic aerosol with a previously established abundance in CHNOS molecules. AU - Tziotis, D. AU - Hertkorn, N. AU - Schmitt-Kopplin, P. C1 - 6742 C2 - 29196 CY - Chichester, West Sussex, U.K. SP - 415-421 TI - Kendrick-analogous network visualisation of ion cyclotron resonance Fourier transform mass spectra: Improved options for the assignment of elemental compositions and the classification of organic molecular complexity. JO - Eur. J. Mass Spectrom. VL - 17 IS - 4 PB - IM Publications PY - 2011 SN - 1469-0667 ER - TY - JOUR AB - Ultra-high-resolution mass spectrometry was used to investigate polyborate species in aqueous solution. The mass spectrum of boric acid revealed clusters of polyborate ions. Constituents with up to 19 B atoms were assigned and 15 species and their relationship were investigated in depth with collision-induced fragmentation. Based on the observed fragments, we proposed herein a potential fragmentation pathway for the observed polyborate molecules. AU - Gáspár, A. AU - Schmitt-Kopplin, P. C1 - 6094 C2 - 27838 SP - 237-242 TI - Identification of polyborate ions in aqueous solution by electrospray ionisation Fourier transform ion cyclotron resonance mass spectrometry. JO - Eur. J. Mass Spectrom. VL - 16 IS - 2 PB - Im. Publications PY - 2010 SN - 1469-0667 ER - TY - JOUR AB - Characterization of humic substances isolated from thermal water and surface water was done by elemental analysis and electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. Atomic ratios derived from elemental analysis represented compositional differences of humic substances. H/C and O/C atomic ratios were also calculated from molecular formulae determined by ultra high-resolution mass spectrometry. The van Krevelen diagram was used to illustrate the bias between the atomic ratios from elemental analysis and mass spectrometry. AU - Kovacs, K.* AU - Gáspár, A. AU - Sajgó, C.* AU - Schmitt-Kopplin, P. AU - Tombacz, E.* C1 - 5911 C2 - 27476 SP - 625-630 TI - Comparison of humic substances isolated from thermal water and surface water by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry. JO - Eur. J. Mass Spectrom. VL - 16 IS - 5 PB - IM Publications LLP 2010 PY - 2010 SN - 1469-0667 ER -