Mass spectrometry is an important enabling technology in bioscience in the 21st century. It is a unique research tool that detects chemical species with high sensitivity and high speed, offering at the same time a wealth of information on the investigated systems.
Our group members develop mass spectrometric methods that address challenging tasks, and have the potential to contribute to new discoveries. Examples of projects include: analysis of skin metabolites as well as analysis of natural compounds in complex matrices such as dairy products, tea, vegetables, and small metazoans.
One of the research projects focuses on coupling robotic arms with sample preparation stages and mass spectrometer as the detector.
This section will soon provide an overview of the main mass spectrometric techniques. Please report any errors to us.
|Electron ionization||EI||Robust, suitable for non-polar volatile compounds||Fragmentation, mainly suitable for analysis of small (volatile) molecules|
|Chemical ionization||CI||Less fragmentation||Limited applicability, decomposition of thermally labile compounds|
|Electrospray ionization||ESI||Extremely useful in analysis of small and large molecules including biopolymers, multiply charged ions can be formed, high sensitivity, compatible with liquid chromatography||Multiply charged ions can be formed|
|Nanospray electrospray ionization||nanoESI||Extremely useful in analysis of small and large molecules including biopolymers, multiply charged ions can be formed, high sensitivity, compatible with nanoflow liquid chromatography||Multiply charged ions can be formed|
|Atmospheric pressure chemical ionization||APCI||Suitable for analysis of medium and non-polar analytes||More fragmentation than in ESI|
|Matrix-assisted laser desorption/ionization||MALDI||Extremely useful in analysis of a wide range of molecules including biopolymers, can be used in MS imaging||Matrix interference, sweet-spot effect|
|Surface-assisted laser desorption/ionization||SALDI||Very useful in analysis of a wide range of molecules including biopolymers, less matrix interference, can be used in MS imaging||Some variants have lower sensitivity|
|Secondary ion mass spectrometry||SIMS||Very high spatial resolution in SIMS imaging||Fragmentation|
|(variants of atmospheric pressure ionization, including: EESI, ESSI, DESI, nanoDESI, and many others)||(too many to list here)||Many of these methods are simple, easy to use, and do not require much sample preparation||Many of these methods still require proper validation and proof of quantitative capabilities|
In some experiments we use standard ion sources (EI and ESI). However, in many other experiments we implement home-made ion sources which are based on the designs published in scientific literature.
|Magnetic field sector||B||High resolution, suitable for isotope ratio analysis||Relatively large, hard to interface with LC, often accompanied by E|
|Electric field sector||E||Focusing and deflecting ions||Requires temporal scan (if used for separation of ions), often accompanied by B|
|Quadrupole||Q||Small, inexpensive||1 unit mass resolution|
|Ion trap||IT||Small, inexpensive, tandem MS capability||Limited mass resolution, discontinuous operation makes it less suitable for quantitative analysis|
|Time-of-flight||TOF||Good mass resolution and accuracy||Large|
|Fourier transform ion cyclotrone resonance||FT-ICR||Excellent mass resolution and accuracy, suitable for identification of molecules based on accurate/exact mass matching||Very expensive, very large, maintenance-intensive|
|Orbital ion trap||OIT||Excellent mass resolution and accuracy, suitable for identification of molecules based on accurate/exact mass matching||Very expensive|
|Triple quadrupole||QQQ||Optimal for quantitative analysis, tandem MS capability||Relatively expensive|
|Quadrupole - time-of-flight||Q-TOF||Good mass resolution and accuracy, tandem MS capability||Relatively expensive, some models are large|
|Quadrupole - ion trap||Q-IT||Hybrid of QQQ and IT, tandem MS capability||Relatively expensive|
|Time-of-flight - time-of-flight||TOF-TOF||Good mass resolution and accuracy, tandem MS capability||Relatively expensive, large|
We implement ion trap and quadrupoles (single and triple) in most of our MS experiments. Access to other instruments is through collaborations.