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The Bruker UltrafleXtreme is a MALDI (Matrix-Assisted Laser Desorption Ionization) time of flight (TOF) TOF mass spectrometer. It uses delayed-extraction for linear mode, reflectron mode and MS/MS (TOF/TOF using LIFT mode) scans. Gas phase ions are formed via laser ablation and desorption of a solid chemical matrix/analyte sample, and are subsequently accelerated down a 2-meter flight tube. The flight trajectory of the ions in the tube can be modeled kinematically, therefore relating the time of flight to the mass to charge ratio (m/z) of the ion. The matrix compound is typically a small organic molecule, chosen for its ability to absorb photons at 355 nm from the frequency-tripled Nd : YAG  laser.  In reflectron mode the UltrafleXtreme has high mass resolving capabilities up to 40,000 and ppm mass accuracy. The UltrafleXtreme is also designed for TOF/TOF, a two stage, tandem mass spectrometry technique that can generate and record MS/MS or MS²­ spectra­.  The incorporated LIFT device allows full fragment ion spectra to be acquired within a single scan. Typical analytes are biomolecules, nanoparticles, and synthetic polymers.

Location: MI 551

System Overview:

• Smartbeam laser acquisition speeds:
  • Max laser rep rate of 2000Hz for MS
  • Max laser rep rate of 1000Hz for MS/MS
• Reflectron mode: 
  • Resolution up to 40,000
  • 1 ppm mass accuracy
• Linear Mode:
  • Resolution up to ~2500
• MS/MS or TOF/TOF mode:  (LIFT mode) Mass spectra can be acquired with up to 1000 Hz laser repetition rate from low fmol levels within seconds.
• Laser: Solid state frequency-tripled Nd : YAG laser at 355 nm with a Gaussian beam profile.
• Digitization rate: sample rate of up to 4 GS/sec.
• For MS Imaging work:
  • Laser focus diameters down to 10 microns for the best spatial resolution imaging.
  • Max laser rep rate of 2000Hz for MS
  • Max laser rep rate of 1000Hz for MS/MS

Sample Preparation:

• Sample and matrix should be prepared in similar or miscible solvent systems.
• Preparation typically only requires 1µL of sample
• Selecting the proper matrix has a large effect on results.  This decision can be based on previous successful MALDI analyses of similar samples, the for polymer samples, or see the general guide found in the Voyager manual (section 3.1.1 - "Selecting a Matrix").
  • Sinapic acid is the most common protein (>10kDa) matrix used.
  • α-cyano-4-hydroxycinnamic acid is the most common peptide (<10kDa) matrix used.
• Samples must be completely dry before loading into the instrument.
• For positive ion samples, a small amount of acetic acid or TFA (0.1% v/v) can be added to enhance the signal.
• Approximate recommended sample concentrations are as follow:
  • Small peptides: 1-10 pmol/µL
  • Proteins: 1-50 pmol/µL
  • Polymers: 1-10 mM

User Manuals

• ULTRAFLEXTREME SERIES USER'S MANUAL [.pdf] Please read for training.
• FLEXIMAGING 5.0 WORKFLOWS MANUAL [.pdf] Please read for training.
• BIOTOOLS V3.2 MANUAL [.pdf] Please read for training.
• FLEXCONTROL USER MANUAL [.pdf] Please read for training.
• FLEXANALYSIS USER MANUAL [.pdf] Please read for training.

The Thermo Scientific LTQ-XL is a linear ion trap (LIT) mass spectrometer with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI) capabilities. The LTQ-XL has MSn capabilities, which is a powerful analytical tool for use in structural analysis. This mass spectrometer can provide molecular weight and sequence information for small peptides (MW below 2000 Da) at the femtomole level with proper analyte introduction. Additionally, liquid seprations prior to MS detection can be made possible by coupling to the Thermo Scientific EASY-nLC 1200 liquid chromatograph with precise gradient flow (water/acetonitrile only) from 20 nL/min to 2 µL/min with pressures up to 1200 bar.

Calibration:

• Automated system calibration performed by CMA staff only

System Overview:

• Mass Ranges: 15-200 Th, 50-2000 Th, 200-4000 Th
• Resolution: 0.05 FWHM with Ultra ZoomScan
• Sensitivity: 250 femtogram reserpine in 1:1 isopropanol:water at 400µL/min flow rate for both MS/MS and MSn.
• ZoomScan for isotopic resolution across full-range scan
• Ultra ZoomScan for ultimate resolution
• Turbo Scan for ultra-fast scan to improve signal-to-noise and sampling rate
• Positive/negative ionization modes
• Multiple Ionization Strategies:
  • Electrospray Ionization (ESI) —
  • Nanoelectrospray Ionization (nESI) —
  • Direct Analysis in Real Time (DART) —
• Pulsed Q Collision Induced Dissociation (PQD) enables trapping of low mass fragment ions.
• High Resolution Isolation allows for the separation of an isobaric interfering species down to 0.3 Da or for isolation of thermally labile compounds.
• Automatic Gain Control (AGC) used to ensure ideal number of ions stored in linear ion trap each scan.
• MSⁿ for n=1 to 15 for structural analysis
• Advanced Data Dependent Experiments possible (i.e. Triple Play, Neutral Loss, Ion Tree)
• Linear ion trap with radial ejection. Dual conversion dynode detectors used to capture high capacity of the ion signal.

Sample Preparation:

• All samples should be in an ESI-friendly solvent system such as 50/50 Water/Acetonitrile, Water/Methanol, etc.
• For positive ion samples, a small amount of acetic or formic acid (0.1% v/v) can be added to enhance the signal.  TFA is not recommended.
• For direct injection, prepare at least 100µL of sample.  For flow-injection analysis 20µL is typically sufficient.
• Recommended sample concentrations are as follow:
  • Small organics: 1-10µM
  • Small peptides: 1-10µM (pmol/µL)
  • Large proteins: 2-10µM (pmol/µL)
  • Polymers: 10-100µM

NanoLC Overview:

• Pressure range: 0-1200 bar
• Flow range: 20-2000 nl/min (Recommended: 100-1000 nL/min)
• Samples injected via autosampler
• Software integration with MS and instrument control using Xcalibur 4.0
• NanoViper fitting technology enables low dead volume liquid flow path connectivity. Minimizes peak broadening due to mixing.
• nano-ESI ionization source developed in-house utilizes a 10 µm emitter.

User Manuals

• Please read for training.
• Please read prior to nLC-MS inquiries.

Applied Biosystems (formerly PerSeptive Biosystems) Voyager STR MS is a matrix assisted laser desorption ionization (MALDI) time of flight (TOF) mass spectrometer. Ions are formed in the gas phase from a laser focused onto a matrix/analyte solid sample. The matrix compound is typically a small organic molecule, chosen for its ability to absorb photons at 337 nm from the nitrogen laser. Gas phase ions (positive ions are typically protonated) are then accelerated down the 2 meter flight tube with 20-25 keV of kinetic energy (KE). Low m/z ions hit the detector first followed by the slower, higher m/z ions. To a first order, the ions follow the equation KE=1/2mv². Typical analyte molecules include polymers, peptides, proteins, and DNA.

Funded by NSF grant #CHE-9808188

Calibration:

• Must be performed on a per-session basis by each individual user

System Overview:

• Mass range 1-400,000 Da
• Positive and negative ion modes
• Linear (R=3000) and reflector (R=15000) modes
• Post-source decay (PSD) with CID
• 337nm nitrogen laser
• 100 well standard sample plate (user-supplied)
• Polymeric analysis tool (PDI, M_n, M_w, M_z calculation)
• 5ppm mass accuracy in reflectron mode with internal reference
• Femtomole-level detection with proper sample preparation

Sample Preparation:

• Sample and matrix should be prepared in similar or miscible solvent systems.
• Preparation typically only requires 1µL of sample
• Selecting the proper matrix has a large effect on results.  This decision can be based on previous successful MALDI analyses of similar samples, the for polymer samples, or see the general guide found in the Voyager manual (section 3.1.1 - "Selecting a Matrix").
  • Sinapic acid is the most common protein (>10kDa) matrix used.
  • α-cyano-4-hydroxycinnamic acid is the most common peptide (<10kDa) matrix used.
• Samples must be completely dry before loading into the instrument.
• For positive ion samples, a small amount of acetic acid or TFA (0.1% v/v) can be added to enhance the signal.
• Approximate recommended sample concentrations are as follow:
  • Small peptides: 1-10 pmol/µL
  • Proteins: 1-50 pmol/µL
  • Polymers: 1-10 mM

Additional Information

• Read Chapters 1,3-5 for training.
• This guide has been created to guide users through a standard operation of the instrument. There are screenshots and illustrations to assist. It is suggested to use this document during your analyses.