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This is a powerpoint presentation solely to give a brief idea about the role of Mass Spectrometry (MS) which is one of the powerful analytical technique.This presentation describes the role of Mass Spectrometry in the field of food industry.These slides deals with the basic principle,working,components,detailed analysis etc.

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  1. 1. Presented by, Erin Davis
  2. 2.  Mass spectrometry (MS) is an powerful analytical chemistry technique  It helps to identify the amount and type of chemicals present in a sample by measuring  mass-to-charge ratio  abundance of gas-phase ions  A mass spectrum is a plot of the ion signal as a function of the mass-to-charge ratio 22-11-2015Mass Spectrometry 2
  3. 3.  It is a used to:  quantify known materials  identify unknown compounds within a sample  to elucidate the structure and chemical properties of different molecules  The complete process involves the conversion of the sample into gaseous ions, with or without fragmentation 22-11-2015Mass Spectrometry 3
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  5. 5.  A mass spectrometer generates multiple ions from the sample  it separates them according to their specific mass-to-charge ratio (m/z)  records the relative abundance of each ion type  The production of gas phase ions of the compound, basically by electron ionization.  This molecular ion undergoes fragmentation.  Each primary product ion derived from the molecular ion, in turn, undergoes fragmentation, and so on. 22-11-2015Mass Spectrometry 5
  6. 6.  A mass spectrum of the molecule is thus produced  It displays the result in the form of a plot of ion abundance versus mass-to-charge ratio  Ions provide information concerning  the nature and the structure of their precursor molecule  In the spectrum of a pure compound,  molecular ion appears at the highest value of m/z  followed by ions containing heavier isotopes  Thus provides the molecular mass of the compound 22-11-2015Mass Spectrometry 6
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  8. 8.  The instrument consists of three major components:-  Ion Source For producing gaseous ions from the substance being studied  Analyzer For resolving the ions into their characteristics mass components according to their mass-to- charge ratio  Detector System For detecting the ions and recording the relative abundance of each of the resolved ionic species22-11-2015Mass Spectrometry 8
  9. 9. In addition,  sample introduction system is necessary to admit the samples to be studied to the ion source  maintain the high vacuum requirements (~10-6 to 10-8 mm of mercury)  computer is required  to control the instrument  acquire and manipulate data  compare spectra to reference libraries 22-11-2015Mass Spectrometry 9
  10. 10.  Produce ions from the sample in the ionization source  Separate these ions according to their mass-to- charge ratio in the mass analyzer  Eventually, fragment the selected ions and analyze the fragments in a second analyzer  Detect the ions emerging from the last analyzer and measure their abundance with the detector that converts the ions into electrical signals  Process the signals transmitted to the computer and control the instrument using feedback 22-11-2015Mass Spectrometry 10 WORKING
  11. 11. Analysis of Biomolecules  Till the1970s, the analytical techniques were electrophoresis, chromatography or ultracentrifugation methods  The results were based on characteristics other than the molecular weight  Exact molecular weight of a macromolecule was found by calculation based on its chemical structure  The development of desorption ionization methods based on the emission of pre-existing ions such as:-  plasma desorption(PD)  fast atom bombardment(FAB)  laser desorption (LD) allowed the application of mass spectrometry for analyzing complex biomolecules 22-11-2015Mass Spectrometry 11
  12. 12.  The determination of the complete structure of oligosaccharides is more complex than that of proteins.  It involves the determination of isomeric nature of monosaccharides and their capacity to form linear or branched oligosaccharides.  Knowing the structure of an oligosaccharide requires determination of monosaccharide sequence  its branching pattern  isomer position  anomeric configuration  Advances in glycobiology involves comprehensive study of structure, bio-synthesis, biology of sugars and saccharides.  Mass spectrometry is emerging as an enabling technology in the field of glycomics and glycobiology 22-11-2015Mass Spectrometry 12
  13. 13.  Lipids are made up of many classes of different molecules which are soluble in organic solvents  Lipidomics constitutes the detailed analysis and global characterization, both spatial and temporal, of the structure and function of lipids within a living system  Many new strategies for mass-spectrometry-based analyses of lipids have been developed. The most popular lipidomics methodologies involves  electrospray ionization (ESI) sources  triple quadrupole analyzers  It determines the mol.wt, elemental composition, the position of branching and nature of substituents in the lipid structure 22-11-2015Mass Spectrometry 13
  14. 14.  Proteins and peptides are linear polymers made up of combinations of the 20 amino acids linked by peptide bonds  Proteins undergo several post translational modifications, extending the range of their function via such modifications  The term Proteomics is the analysis of complete protein content in a living system, including co- and post-translation modified proteins and alternatively spliced variants  Mass Spectrometry allows the determination of the mol.mass of peptides  It is used for protein identification, de novo sequencing, identification of post-translational modifications 22-11-2015Mass Spectrometry 14
  15. 15.  Oligonucleotides (DNA orRNA), are linear polymers of nucleotides.  It is composed of a nitrogenous base, a ribose sugar and a phosphate group.  Oligonucleotides may undergo several natural covalent modifications in tRNA and rRNA resulting from reactions with exogenous compounds  Mass spectrometry plays an important role in the determination of  structural modifications  Positions and mol.wt of oligonucleotide 22-11-2015Mass Spectrometry 15
  16. 16. SimGlycan®  Predicts the structure of glycans and glycopeptides from the MS/MS data acquired by mass spectrometry, facilitates glycosylation and post translational modification studies  It accepts the experimental MS profiles, of both glycopeptides and released glycans, matches them with its own database and generates a list of probable structures  It also supports multi stage mass spectrometry data analysis which enables structural elucidation and identification of fragmentation pathways 22-11-2015Mass Spectrometry 16
  17. 17. SimLipid  Innovative lipid characterization tool which enables structural elucidation of unknown lipids using MS/MS data  This software analyzes lipid mass spectrometric data for characterizing and profiling lipids  Annotate mass spectra with the lipid structures identified using abbreviations  Studies the effect of ionizing energy on molecules. It depends upon chemical reactions in the gas phase in which sample molecules are consumed during the formation of ionic and neutral species 22-11-2015Mass Spectrometry 17
  18. 18.  Digest the protein to peptides (in gel or solution). MS gets limited sequence data from whole proteins, but easily analyze peptides  Trypsin is used for digestion. Majority of peptides are ideal size for analysis, and peptides behave nicely in mass spectrometer  Separate peptides, usually on reverse phase column with acetonitrile gradient(column dia 75 µm) We use acetic acid in the solvent.  Place ionized peptides in vapour phase by passing the column elute, containing peptides and solvent, to form tiny droplets. After evaporation of solvent, peptides are left in the vapour phase. Charged surfaces move the ionized peptide into the MS22-11-2015Mass Spectrometry 18
  19. 19.  Using chromatography to introduce molecules into a mass spectrometer is LC-MS or HPLC-MS  Measure mass of peptides  Fragment peptides -- A collision with gas molecules fragments peptides at peptide bonds. This is CID (collision induced dissociation) or CAD (collisionally activated dissociation)  Measure mass of fragments from peptides. Because there are two steps of mass spectrometry (mass of peptide, mass of fragment of peptide), this is called MS/MS, or MSn because there can be 2 or more fragmentation steps. A two step process is also called tandem mass spectrometry  Use fragment mass data to determine the sequence of the peptide by seeing which combinations of amino acids gives the observed masses of peptide fragments 22-11-2015Mass Spectrometry 19
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