University of Vermont

College of Arts and Sciences

Department of Chemistry

UVM Chem Dept Instruments

Overview of Instrumentation

NMR spectrometers

  • Bruker AVANCE III 500 MHz high-field NMR spectrometer (installed 2012) with multi nuclear observation capability for routine measurement of a number of nuclei.
    • The Bruker is normally fitted with a direct detection SMARTProbeTM for liquids with digital tuning for observation over the range from 15N to 31P as well as 19F with 1H decoupling. The probe also provides enhanced 1H observe capabilities, making it best suited for rapid acquisition of 1D experiments.
    • The Bruker also has a VTN mutlinuclear double resonance magic angle spinning MAS-II solid state probe for running solid samples.
    • There is also an inverse triple resonance (TXI) probe for liquid samples for observation of 1H while decoupling 13C and 15N, including 2D lock.
  • Varian UNITY INOVA 500 MHz high-field NMR spectrometer with multi nuclear observation capability for routine measurement of standard nuclei (1H, 13C, 15N, 19F & 31P) and other nuclei as needed. This NMR is ideally suited for performing 2-dimensional and more complicated NMR experiments.
    • The Varian has pulsed field gradient (PFG) capability, and is generally fitted with an inverse detection probe providing multidimensional capability. The PFG allows
      • Use of programs such as "Watergate" to render water invisible permitting acquisitions in H2O instead of D2O as solvent.
      • Rapid field recovery in multidimensional experiments cutting acquisition times in half.
  • Experiments in the following modes: INEPT, DEPT, COSY, 2DJ, TOCSY, NOESY, ROESY, EXSY, HMQC, and HMBC (providing the requisite tools for structure elucidation)
  • The pre-acquisition delay (PAD) macro on the Varian allows a reaction to be followed in situ and array the resulting spectra to show the rate of product growth. More rigorous kinetics macros such as DOSY are also available on the Varian.
  • The UVM NMR facility has the capability to tune, match, and observe the following isotopes: 1H, 2H, 7Li, 11B, 13C, 14N, 15N, 17O, 19F, 27Al, 29Si, 31P, 47Ti, 51V, 79Br, 81Br, 87Rb, 91Zr, 97Mo, 109Ag, 119Sn, 129Ze, & 195Pt.
  • Dual alumina columns are used to lower the dew point of air to -72 °C facilitating low temperature operation of both the Bruker and Varian platforms in dynamic NMR studies.
Use of the NMR instrumentation:
  • The first step is to set up an NMR user account through the Univ. of Georgia Faces Scheduling System. Our group name is UVMNMR. Go to https://docs.google.com/forms/d/1EhiXSZudDUUZWSbR26556m7wYkMyhv74Po2jV_0-xdA/viewform. You should then receive an email in the next 24 hours that an account has been set up for you.
  • New users must first be trained by the NMR Interim Facility Manager, Dr. Monika Ivancic, to perform routine 1D NMR spectra of 1H and 13C spectra. Contact Monika.Ivancic@uvm.edu to be trained on use of the NMR instruments. New users must be certified to run the NMR instruments.
  • Once trained, log into the on-line NMR scheduling system http://faces.ccrc.uga.edu/ to schedule NMR instrument use.  Remember that the "Group name" for scheduling is UVMNMR. Note also that this application uses Javascript.
IMPORTANT:

Please review the NMR facility guidelines & policies


Mass spectrometers

  • An Applied Biosystems 4000QTrap Pro high performance hybrid triple-quadrupole/linear ion trap liquid chromatograph-mass spectrometer (LCMS) with collision induced dissociation (CID) capability for MS/MS and for MSn using the ion trap. The ABI 4000QTrap has both the scanning functions of a triple quadrupole with the scanning functions of a linear ion trap that can perform simultaneously in both modes within a single injection/analysis automatically through the software.
  • Other features include:
    • Operation in both negative and positive ion mode
    • mass range of m/z = 5 to 2,800 in Q1 and Q3 in RF/DC mode and m/z = 70 to 2,800 in linear ion trap mode
    • maximum scan speed of 2,400 amu/sec in RF/DC mode and user-settable scan speeds of 250 amu/sec, 1000 amu/sec and 4,000 amu/sec in linear ion trap mode
    • A number of operational modes are available, including product ion scanning for structural elucidation and precursor ion and neutral loss scanning
    • Three modes of LC spray ionization: (i) atmospheric pressure chemical ionization (APCI), (ii) "Turbo IonSpray", i.e. ESI, and (iii) Nanospray ESI
    • The LC interfaced to the 4000QTrap a Shimadzu with nano-LC capability
    • A full suite of instrument control and data processing software are available
  • Varian Saturn 2100T gas chromatograph-mass spectrometer (GCMS) with a Varian 3900 GC and CP-8400 autosampler
    • The GCMS is an ion trap with a m/z = 10-650 mass range
    • The ion trap operates in electron impact ionization (EI) and positive chemical ionization (PCI) modes
    • Especially useful in PCI mode is the collisionally induced dissociation (CID) option to acquire MS/MS spectra
    • The GCMS is primarily used for automated detection of mixture components and for selected ion monitoring (SIM) for quantitation
  • Applied Biosystems Voyager-DE Pro Biospectrometry Workstation matrix assisted laser desorption-time of flight (MALDI-TOF) mass spectrometer located in the Department of Biochemistry. The MALDI-TOF has a 337-nm N2 3-ns pulse UV laser, 1.3-m linear flight tube, and a 2.0-m flight tube in "reflectron" mode. The unit can measure both positive and negative ions. In linear mode, it has a ~300-kDa mass range and a resolution of >2000 for small proteins (m/z <20 kDa) and of ~50 for large proteins (m/z ~100 kDa). With the reflector on, the resolution is >7,000 at m/z <6 kDa. Peptide ions are resolved at better than unit resolution with the reflector operating. The TOF has "post-source decay" capabilities.
Submitting samples for mass spectrometry analysis by GCMS, LCMS or MALDI-TOF:
  • Download the sample submission form as an Adobe PDF
    • Fill the form out completely and print. Incomplete forms will result in delays in the analysis.
    • Submit a printed copy of the form to Bruce O'Rourke's mailbox in Cook.
  • Place a vial, labeled with your sample ID, containing >1 mg (solids) or >10 μl (liquids) in the box in the cold room on the 3rd floor. Samples are to be submitted in screw-cap vials. For limited sample quantities, V-shaped interior vials (0.5-mL) or Eppendorf centrifuge tubes are preferred. Air sensitive samples should be submitted in a vial with a septum.
  • Contact the mass spectrometry facility manager, Bruce O'Rourke, with any questions about your samples, their analysis, or for more information concerning specialized sample analysis
  • Can I be trained to use the mass spectrometry instrumentation?
    • In general if you only have one or two samples to be analyzed every now and then, it probably is not worth it the large amount of time that needs to be invested to become proficient enough on any of the mass spectrometers
    • If you have a research project that will generate a large quantity of samples that can be analyzed in a similar way, contact Bruce O'Rourke for training
    • Generally it is much easier to be trained on the GCMS, then the MALDI-TOF, with the most training required for the LCMS

X-ray diffractometers (XRD)

  • A Bruker Smart Apex II single crystal, X-ray diffractometer (new 2011).  The XRD has a ceramic molybdenum source and a 4 ºK CCD detector for the structural characterization of crystalline small molecule, mineral, and thin film samples. With the low-temperature Oxford Cryostream option, the XRD can collect data across a wide range of temperatures (80–400 °K) .

Electron paramagnetic resonance (EPR) spectrometer

  • An E300 Bruker spectrometer for characterization of paramagnetic materials by electron spin resonance (ESR) spectroscopy. The instrument operates at ~9 gHz, commonly referred to an "X-band" and is suitable for work between 77 °K and room temperature. It has variable temperature capabilities and can be used on both liquids and solids.

Inductively coupled plasma (ICP) optical emission spectrometer (OES)

  • A Perkin-Elmer Optima 7000DV ICP OES with a CCD array detector and a cyclonic spray chamber & concentric nebulizer for liquids.  The ICP includes a Perkin-Elmer S10 autosampler and peristaltic pump for sample input under computer control for automated measurements.

Fourier-transform infrared spectrometers (FT-IR)

  • Shimadzu IRAffinity-1 FT-IR spectrometer with IRPrestige-21 software, attenuated total reflectance (ATR) head, and a gas cell to measure solids, liquids and gases.
  • Thermo-Nicolet FT200 FT-IR spectrometer with attenuated total reflectance (ATR) head for solids and liquids.

Also available are UV/visible, fluorescence/phosphorescence and CD spectrometers, an atomic absorption spectrometer, a thermal-gravimetric analysis system, GC and HPLC systems, a magnetic susceptibility balance, an ultracentrifuge, a scintillation counter, and a walk-in cold room.


Last modified May 03 2014 07:21 AM

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