Laboratory techniques I

Aims

The main aims of this course are: To provide essential background in the analytical techniques most frequently encountered in the qualitative, quantitative and structural chemical analysis employed in organic chemistry, food chemistry and chemistry of natural products.   To introduce the principles of operation of the analytical instruments described and elaborate on their applications.   To provide the students with the skill to perform the structural determination of organic molecules by interpreting the mass and nuclear magnetic resonance spectra of a compound.    

Prerequisites

Subunits 3, 4, 8
 
  

Learning Outcomes

After the completion of the course, the students will be able to:   Describe in detail the principles of operation of gas chromatography, the different types of columns and the principle types of detectors used in this technique.   Design a gas chromatography analysis suitable for the separation of a mixture by considering the parameters that influence the analysis (e.g. type of column, temperature programme, flow rate, suitable detector).   Describe in detail the principles of operation of Mass Spectroscopy.   Describe the major vacuum ionization techniques [Electron Ionization (EI), Chemical Ionization (CI) and Fast Atom Bombardment (FAB)] and decide which technique is suitable for a specific analysis.   Illustrate the fragmentation patterns of various families of organic compounds.   Interpret a mass spectrum by assigning the peaks and perform the structural characterisation of a given molecule.   Describe in detail the principles of operation of Nuclear Magnetic Resonance (NMR).   Perform the interpretation of the 1H and 13C NMR spectra of an organic compound and determine the structure of the molecule based on the spectral information.   Combine NMR and MS spectral data in order to perform a full structural assignment of unknown compounds.          

Syllabus

This unit aims to provide students coming from a variety of disciplines (agriculture, horticulture, biology, biochemistry, food technology, dietetics and nutrition) with a comprehensive understanding of the analytical techniques most frequently encountered in the qualitative, quantitative and structural chemical analysis employed in organic chemistry, food chemistry and chemistry of natural products The course outline includes: a)     Gas Chromatography: i)        Principles of operation. ii)      Instrumentation: types of columns, principle types of injectors and detectors iii)    Parameters affecting the analysis: temperature, chemical structure of stationary phase, flow rate. iv)    Evaluation criteria for the choice of the ideal conditions for a specific gas chromatographic analysis.   b)     Mass Spectroscopy: i)        Principles of operation ii)      Instrumentation: sample introduction techniques, ionisation techniques (EI, CI and FAB), quadrupole and magnetic sector mass spectrometers. iii)    Mass spectra interpretation: structural factors, isotope abundance, major fragmentation patterns of some classes of organic compounds.   c)      Nuclear Magnetic Resonance Spectroscopy: i)        Principles of operation: spin/magnetic field interaction for a nucleus, larmor frequency, pulsed NMR. ii)      Instrumentation: superconductive magnets, radiofrequency generators. iii)    Information obtained from a NMR spectrum: chemical shift, shielding and deshielding of the nuclei, integration, hyperfine structure caused by spin-spin coupling, multiplicity of peaks. iv)    1H and 13C NMR spectra interpretation and structural determination of organic compounds.    

Content Delivery

It unit is a fundamental course, which in combination with Units 3, 4, 8 and 14 enables students to acquire an in-depth knowledge of the most important analytical techniques that are used in the separation and structural determination of compounds. Students are expected to learn the principles of operation of the techniques and acquire the skill to combine the information obtained from each technique in order to completely characterise a molecule.   The delivery of the unit is accomplished through lectures and includes active participation of the students throughout the course as they are asked to solve problems, interpret spectra and perform full structural determination of organic compounds. This involves both individual and group working. Problem solving in the classroom is essential in order to achieve the learning outcomes of this course and induces collaboration skills.  

Coursework And Assignment Details

The assessment of this course is a written examination which consists of multiple choice questions, true or false statement characterisation with full justification required and problem solving on structural determination of organic molecules based on their MS, 1H and 13C NMR spectra.   The students are informed about the type of assessment during the course and have solved similar exercises and problems throughout the course.