Time-of-flight (TOF) mass spectrometry (MS) works by imparting equal energies to all fragments. Since smaller particles thereby travel faster, their masses are determined by how quickly they travel from the source to the detector.

TOF provides exquisite mass accuracy and resolution at very high dynamic range and response linearity within a spectrum.

Top 6 Questions You Should Ask When Buying a time-of-flight Mass Spectrometer

1. What kind of mass accuracy, resolution, and response linearity do you require in your work? If you need very high-quality accuracy, resolution at a high dynamic range and response linearity in a spectrum, a time-of-flight mass spectrometer (TOFMS) is likely a wise choice. If these requirements aren’t important to your work, a TOF-MS probably isn’t what you need.

2. What kind of software package does the instrument come with? If non-experts will be using the instrument often, easy-to-use software that takes over routine tasks such as data entry is a must.

3. How large is the instrument and how much space do you have to work with in your lab? Make sure the instrument fits and is easy to access!

4. Does the system include the mass analyzer, detector, and ion source in one package or do these components need to be purchased separately? Which option makes the most sense for your current and future applications? How much does each cost?

5. What kind of service and support does the company provide for the TOF-MS?

6. What is the cost of acquisition, use, and maintenance of the instrument?

How time-of-flight (TOF) mass spectrometers stack up against other types of MS instruments our readers have recently purchased or are planning on buying for their laboratories:

Fourier transform ion cyclotron resonance (FTICR) mass spectrometry 3%
GC-MS 28%
Inductively coupled plasma mass spectrometry (ICP-MS) 14%
Matrix-assisted laser desorption/ionization (MALDI) 7%
Thermal ionization mass spectrometry (TIMS) 3%
Time-of-Flight (TOF) 13%
Triple Quad 19%
Don’t Know 9%
Other 5%

Recent Trends in MS-TOF:

• Today’s instruments, particularly MS/MS TOF mass spectrometers, are routinely used in proteomics, protein discovery, lipids, metabolomics, and drug and drug metabolite identification. Pharmaceutical companies, in particular, use these instruments to quantify and positively identify known and unknown compounds.

• The greatest strides in MS-TOF usability have been in software design. Software opens a mass spectrometer’s full range of features to expert users while simplifying protocols for routine users through various levels of permissions.

Recently Released TOF Mass Spectrometers

TripleTOF™ 4600 LC/MS/MS
• Acquires high resolution accurate mass MS and MS/MS data at up to 50 spectra per second
• Integrates comprehensive qualitative exploration, rapid profiling, and high-resolution quantitation workflows on a single platform
• Over 50 hours of continuous LC/MS operation provides


FasTOF™ High-Res TOF GC/MS
• A pulsed mass calibration system compensates for temporal drift in mass calibration parameters
• GC Image Software fully supports high resolution mass spectrometric analyses, including exact mass measurements and elemental composition determinations
• The FasTOF™ Ion Source provides adjustable 0 eV to 100 eV electron impact ionization • Provides tunable mass resolution of up to 5,000


Bench TOF- DX
• Allows for full range spectral data at quadrupole SIM sensitivity levels (>800:1 s/n for 1 pg OFN while acquiring over full mass range)
• Offers high speed spectral acquisition (10,000 Hz) for compatibility with fast GC, GCxGC (Comprehensive 2D GC) and complex conventional GC profiles
• Provides a mass range of 1 to 1000 amu


Q-TOF LC/MS 6550
• iFunnel technology increases ion transfer to achieve the lowest detection levels of any high resolution LC/MS instrument, achieving low femtogram-level sensitivity
• Ion Beam Compression and Shaping (IBCS) technology provides great sensitivity while maintaining 40k mass resolution and sub ppm mass accuracy from m/z 20-10,000


TOF Mass Spectrometer Manufacturers

AB Sciex www.absciex.com
Agilent www.agilent.com
ALMSCO International www.almsco.com
DANI Instruments www.danispa.it
LECO www.leco.com
Waters www.waters.com
Thermo Fisher Scientific www.thermoscientific.com
Zoex www.zoex.com