ANALYTICAL TECHNIQUES AND METHODOLOGIES IN MASS SPECTROMETRY
Learning outcomes of the course unit
Knowledge and understanding
knowledge regarding the instrumentation, ionization systems, ion separation and hyphenation with the separation techniques used in mass spectrometry. - Acquire the basic knowledge for the interpretation of a mass spectrum obtained in an electronic impact. Comparison with other ionization techniques such as chemical ionization
- knowledge of the potentials, limits and problems related to the type of ionization, analyzer and data acquisition method.
- knowledge regarding the chromatographic and electrophoretic parameters useful for the use of the best instrumental analytical technique to solve an analytical problem, including sample preparation techniques.
The student have to be able to assess the potential and critical points of the various analytical techniques and methodologies as well as make the correct decisions on how to deal with a problem related to the type of the sample under consideration and evaluation of the analytical data obtained.
The student have to be able to demonstrate the necessary capacity in describing with the appropriate and more pertinent technical terms.
The student must demonstrate to be able to use independently and critically the teaching material provided by the teacher, as well as other independently found , demonstrating the degree of scientific growth gained.
Course contents summary
Reference to separative analytical techniques, such as capillary chromatography and capillary electrophoresis, commonly coupled with mass spectrometry
Ion sources: EI, CI, ESI, APCI, APPI, MADLI, ICP
Mass Analyzer: quadrupole, QTOF, FTICR
Aquisition modes for qualitative and quantitative analysis.
Applications: Proteomics, food contaminates, packaging (food contact materials), clinical applications
Introduction to mass spectrometry and general principles. Historical background and recent developments in mass spectrometry. Mass spectrum and its representation. Atomic mass unit; definition of nominal mass, average mass and monoisotopic mass. Isotopic ions: determination of m + 2 isotopic abundances in molecules containing chlorine, bromine or both atoms. Calculation of the intensity of the isotopic peaks. Mass spectrum of bromopropane and 2-chloropropane.
Description of the essential components of a mass spectrometer: systems for producing high vacuum; sample introduction systems; LC-MS, GC-MS and CE-MS; Ion sources; hard and soft ionization techniques in GC-MS: electronic ionization (EI) and chemical ionization (CI). Ionization techniques in LC-MS: chemical ionization at atmospheric pressure (APCI), atmospheric pressure photoionization (APPI), ionization by electronbulization (ESI). CE-MS coupling.
Source for laser-assisted laser desorption / ionization (MALDI) and SELDI (Surface Enhanced Laser Desorption / ionization). Mass analyzers: magnetic and electro-magnetic field (double focusing) quadrupole, ion trap, timeof flight (TOF). Fourier transform mass spectrometry: Orbitrap and cyclotonic ion resonance analyzer. Hybrid instruments. Detectors and data acquisition. Tandem mass spectrometry. Interpretation of mass spectra; procedures for interpreting mass spectra of organic molecules obtained by electron ionization and other ionization techniques. Applications and quantitative analysis. Mass spectrometry coupling with chromatographic, gaseous and liquid and electrophoretic capillary techniques. Application of mass spectrometry techniques to the study of biomolecules: examples of development of GC-MS, LC-MS and CE-ME methods. Proteomics: Botton-up and Top-down approaches. Selection of some scientific publications applied for the separation and identification of: 5-HMF, furosine, bisphenol A, isopropyl thioxantone.
1 - Search in NIST library of mass spectra for the identification of unknown compounds (criteria for the comparison of the unknown spectra with those of the library)
2 - Determination of acrylamide in samples of foods subjected to different cooking processes
3 - Determination of oligosaccharides of prebiotic interest by high-performance anion exchange chromatography with pulsed electrochemical detection (HPAEC-PED)
lecture notes and power point presentations provided by the teacher. All the material presented in class is available online
Classroom exercises (interpretation of mass spectra, simulation optimization of separative methods of ifenated systems (GC-MS; LC-MS, CE-MS);
Laboratory (GC-MS, LC-MS)
Assessment methods and criteria
Oral exam related to the theory, the instrumentation and the interpretation of mass spectra illustrated during the course and provided to the students with the didactic material