Mass spectrometry and food
- How does it work?
- What can it be used for?
- What can it not be used for?
- Related Facilities
- Further Information
|Key words||Highly sensitive quantitative analysis, isotope ratio analysis, food analysis.|
How does it work?
|Primary objective|| Mass spectrometry (MS), is a widely used analytical tool that provides a blend of rapid, sensitive and selective qualitative and quantitative analyses with the ability to identify organic compounds.
MS is able to quantify known analytes and to identify unknown molecules at the picomoles or femtomoles level [1-4].
|Working principle|| A mass spectrometer is an instrument which volatilizes and ionizes molecules and measures the ion abundance as a function of the ionic mass-to-charge ratio. Mass spectrometers operate by ion formation, separation of ions according to their mass –to-charge (m/z) ratio and detection of separated ions.
Fig.1 presents the working principle of the MS (VS=vaporized sample, Ionization = ionization and fragmentation of sample molecules, Acceleration = acceleration of ions and ionized molecule fragments, Defl = deflection of ions and molecule fragments, D = detection of ionized species).
Fig.1 The deflection process of the ions and ionized molecule fragments takes places due to their motion in a magnetic field and the trajectory radius is given by the formula.
where m = ion mass, v = ion velocity, q = ion electric charge, B = magnetic field
Fig.2 presents the principle of the separation process for a mixed ion stream (I1+I2+I3) in the component ion species (I1+I2+I3) during the ions motion in a magnetic field. The ions species (I1, I2 and I3) are separated having different trajectories (each trajectory radius is proportional to the m/q ratio of the specific ion).
Fig.2 The MS technique is ideal for the identification of different compounds of interest. Compounds identification is provided by matching the mass spectrum of the sample peak with those of a pure compound previously analyzed under identical instrumental conditions. The mass spectra libraries (Wiley, NIST, EPA) are successful for compounds identification [5-9].
The application of mass spectrometry (MS) to large biomolecules has been revolutionized in the past decade with the development of electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI) techniques. ESI and MALDI permit solvent evaporation and sublimation of large biomolecules into the gaseous phase, respectively.
|Additional effects||MS is a destructive analytical method.|
|Important process parameters|| sensitivity, linearity, precision, selectivity, specificity
Among the analytical tools, MS offers the highest information for the smallest amount of sample [10-12].
|Important product parameters|
What can it be used for?
|Products|| MS is useful for food and nutrients control, as listed:
|Operations||Quality control, fermentation process control, food processing and qualitative study.|
|Solutions for short comings||MS provides a precise and accurate analysis for liquids and solids food products.|
What can it NOT be used for?
|Products||Restrictions are related only to the equipment performances. There are many types of MS and the equipment must be appropriate to the sample characteristics.|
|Other limitations||Sampling could be sometimes laborious. The samples need to be extracted from the different matrices. The type of MS should be appropriate to the volatility of the compounds.|
|Risks or hazards||-|
|Maturity||GC/MS is a mature analytical technique.|
|Modularity /Implementation||Simple low cost MS equipments are available in order to measure specific analytes. Some MS measurements can be robotized (autosamplers for liquid and gas samples are available).|
|Consumer aspects||Since MS is a high precision and high sensibility technique it can offer high credibility and safety to the consumer.|
|Legal aspects||There is no specific regulation concerning the use of MS. This analysis technique is required when high precision analysis is needed or when very low levels of analytes have to be detected and measured.|
Facilities that might be interesting for you
|Companies||Thermo Scientific, Waters, AB SCIEX|
sensitivity, linearity, precision, selectivity, specificity Among the analytical tools, MS offers the highest information for the smallest amount of sample [10-12].warning.png"sensitivity, linearity, precision, selectivity, specificity Among the analytical tools, MS offers the highest information for the smallest amount of sample [10-12]." cannot be used as a page name in this wiki.