Description
Introduction to MALDI-TOF-MS
Matrix-assisted laser desorption/ionisation with time of flight mass spectrometry (MALDI-TOF MS) is a rapid, accurate, and sensitive technique that can provide molecular mass and structural information of compounds like proteins & peptides, food carbohydrates, plant cell wall constituents, phytochemicals, and lipids. MALDI-TOF-MS is uniquely suitable for the analysis of biological oligo- and polymers.
Due to its large mass range (up to 500 kDa), MALDI-TOF-MS is complementary to other mass spectrometric techniques that are limited by much smaller mass ranges. The Bruker Autoflex maX LRF can achieve mass accuracies down to 2 ppm and the mass resolution goes up to 26,000 in reflectron mode. The main applications of MALDI-TOF-MS are related to analysis of diverse oligo- and polymeric molecules. These types of molecules are ubiquitous in biological samples from a wide diversity of sources, including food, biomass, and (micro)biological systems. Several specific applications of MALDI-TOF-MS can be found below. Some of the main advantages of this technique include ease of sample preparation, short measuring time, and high sample throughput.
Principle
In short, the principle of matrix-assisted laser desorption/ionisation with time-of-flight mass spectrometry (MALDI-TOF-MS) is as follows. Sample material is co-crystallised with a matrix compound and irradiated with a laser for ionisation. After ionisation, the ionised molecules are accelerated in an electric field and the time-of-flight is measured with the TOF mass analyser, giving their mass-to-charge ratio (m/z) which can be directly related to the analytes’ molecular mass.
Technical Details
Supplier: Bruker Daltonics (Bremen Germany)
Specifications: Bruker Autoflex maX LRF
- 2 kHz smartbeam-II™ laser technology enables efficient ionisation, ultra-high data acquisition speed, and high sensitivity
- Laser focus diameters down to 25 μm for versatile applications
- Positive and negative ionisation modes
- Wide mass range (≤500,000 Da)
- Mass resolution ≥ 26,000 (reflector mode)
- Mass accuracy: linear < 100 ppm (external calibration); reflectron < 10 ppm (external calibration) or < 2 ppm (internal calibration)
- MALDI-Ion Source with integrated self-cleaning procedure
Applications
- Proteomics, analysis of intact proteins, and de novo sequencing of peptides & proteins
- Identification of modified peptides & proteins (e.g. N- or O-glycation, phosphorylation)
- Profiling and identification of charged and neutral oligo- and polysaccharides
- Elucidation of complex structures that constitute plant cell walls
- Monitoring degradation biomass polysaccharides and lignin
- Monitoring digestion or metabolism of food and feed constituents
- Structural characterisation of (oligomeric) phytochemicals
- Lipidomics and profiling of (oxidized) food lipids
- Species identification of food-related (pathogenic) microorganisms
- Characterisation of (biobased) polymers