Wir bieten Forschenden des Departments Chemie und Biochemie Zugang zu einer Vielzahl von massenspektrometrischen Analysemethoden: Akkurate Ionenmassenbestimmung bei hoher Auflösung mit Elektrospray (+/-)ESI-HR MS, mit GC-Elektronen Ionisation GC-EI-HR MS, oder mit Chemischer Ionisation GC-CI-HR MS, GC-EI-MS-Routine-messungen bei Einheitsauflösung, oder ESI-MSn Produktionenspektren. Ist Ihnen nicht klar, welche MS-Methode Ihr Problem löst? Sprechen Sie uns bei der Probenabgabe an! Wir informieren und beraten gerne.
Für polare, ionisierbare organische Verbindungen. Ermöglicht akkurate Ionenmassenbestimmung, Summenformelbestätigung sowie MSMS-basierte Strukturaufklärung. Sehr gut geeignet für polare Verbindungen wie Peptide und auch für Makromoleküle wie Proteine. Ionisation: (+/-)ESI / Nano-ESI
Für unpolare, flüchtige organische Verbindungen mit molaren Massen bis ca. 1000 g/mol. Akkurate Ionenmassenbestimmung auch in komplexen Gemischen. Direkteinlass (DIP) für thermisch stabile Reinstoffe verfügbar. Ionisation: EI (70 -15 eV) / CI (Methan)
Analytik und Gemischtrennung mit GC von unpolaren Verbindungen, Reinheitskontrollen und Substanzidentifikation. Schnelle Ergebnisse im automatisierten Betrieb (bis zu 8 Proben sequentiell). Direkteinlass (DIP) möglich. Ionisation: EI (70 eV)
Formular herunterladen, Probenname, Lösungsmittel, Molmasse (falls bekannt) und gewünschte Methode angeben.
ESI-MS: Probe in geeignetem Lösungsmittel lösen (empfohlene Konzentration ca. 10⁻⁵ bis 10⁻⁷ mol/L).
GC-MS: Probe in organischem Lösungsmittel lösen oder unverdünnt einreichen.
Probengefäß mit Name, Datum und Probenbezeichnung beschriften.
Probe und ausgefülltes Auftragsformular zusammen im MS-Labor (OC Labor 318) abgeben.
Bei Unsicherheit zur Methodenwahl vorab Kontakt aufnehmen.
Ergebnisse werden per E-Mail übermittelt.
Zugriff auf Messdaten der Abteilung für Massenspektrometrie auf einem zentralen Netzlaufwerk (SoFS). Hier finden Sie das Anmeldeformular, Einrichtungsanleitungen und alle Informationen zum Zugriff.
Accurate ion mass determination with HR-EI-MS:
HR-GC-EI/MS and HR-DIP-EI/MS analyses were performed on a Thermo Scientific Exactive GC Orbitrap GC-MS system (Thermo Fisher Scientific, Bremen, Germany). Samples were dissolved and diluted in unpolar to moderately polar solvents (hexane, dichloromethane, ethyl acetate; conc. 10-4mol/l). Typically, 1 μl of sample solution was injected into the GC at an injector temperature of 300 °C and with a split ratio of 1:10. Mixtures were either fractionated on a Thermo Scientific TraceGOLD™ TG-5 SilMS capillary column (30 m 0.25 mm, i.d. 0.25 μm film thickness) with an oven temperature that ranged from 50 °C to 310 °C. Clean one component samples were directly introduced into the mass spectrometer via a temperature-controlled direct inlet probe (DIP). Specific information on the GC-T program and the sample introduction via DIP is given on the results sheet. The carrier gas was high purity helium under a constant column flow rate of 1,2 ml/min. The mass spectra were generated by electron ionization at electron energies of 70 eV or 20 eV, respectively and recorded over a mass range of e.g. m/z 50–1500. The ion source temperature was 250 °C. Details are found on the results sheet. XCalibur software (Thermo Fisher Scientific) was used to process the raw data. The mass spectrometer was tuned and externally-calibrated (m/z 50–550) using PFTBA (CAS 311-89-7) to achieve mass accuracy between 1–3 ppm. The instrument is typically operated at a mass resolution of R = 60.000 (full width at half maximum FWHM, @ m/z 200).
Accurate ion mass determination with HR-ESI-MS:
Cations are determined with (+)ESI-MS and anions with (-)ESI-MS. (+)ESI-MS and (-)ESI-MS analyses were performed on a Thermo Scientific THERMO Scientific LTQ Orbitrap XL system (Thermo Fisher Scientific, Bremen, Germany) equipped with a heated (H)ESI Ion-Probe at a typical spray capillary voltage of 3.2kV. Standard conditions for accurate ion mass determination with HR-ESI-MS are: sample intro-duction via LC-MS in a flow injection mode with an injection volume of 10,0 µl in an isocratic flow of MeOH or CH3CN (sample is led through a deactivated fused-silica capillary to the ion source). Alternatively, the sample can be directly introduced via a syringe pump at similar ion source conditions. The orbitrap analyzer is operated at a resolution of R = 30.000 (full width at half maximum FWHM, @ m/z 200). Accurate ion masses are measured in comparison with appropriate ions of reference compounds used as internal calibration standards in a lock-mass experiment to achieve mass accuracies between 1–3 ppm. Details on the reference material and the lock mass ions used and additional information on the individual measurement is given on the results sheet. XCalibur software (Thermo Fisher Scientific) is used to process the raw data.
Personnel in the MS Facility provide essential services to their users. It is important to recognize their contributions to the scientific advancement of the projects. The type of appropriate appreciation may differ depending on the projects and input.
References to the facilities are a crucial metric of the value of analytical facility services and enables them to demonstrate the importance for the Department and faculty. This ultimately helps to justify the need for existing and new equipment. For our records, we kindly ask the authors to send us the reference of the papers or thesis.
The Investigators are always requested to recognize the contributions of the MS Facility in producing data for publication or thesis in the acknowledgement section of the manuscript. More details in the terms of use (Nutzungsordnung) of the MS Facility.
A template sentence for use in acknowledgements is given below.
„Mass spectrometric characterization and data analysis of the compounds was performed in the MS facility of the Department of Chemistry and Biochemistry at the University of Cologne which benefits from generous funding by the German Science Foundation DFG. The contribution of the MS facility is kindly acknowledged.“