Instrumental Methods of Analysis

Objectives

The curricular unit aims to provide the fundamentals in the field of physical chemistry techniques commonly used in the laboratory: spectroscopy and electrochemistry, but sometimes only in optics users. It is thus intended that the student understands the phenomena in its origin enabling them to intervene in the future, both in terms of technical development or in the interpretation of experimental data.

As specific objectives: i) the concept of electromagnetic radiation interaction with matter;  ii) fundamentals of atomic and molecular spectroscopy with a focus on UV-Vis, IR and Fluorescence iii)  basics of spectrophotometry, graphite furniture, flame, icp iv) fundamentals of electrochemical methods; v) Mass Spectrometry; VI) Other modern techniques of analysis.

General characterization

Code

10709

Credits

6.0

Responsible teacher

Carlos Lodeiro Espino

Hours

Weekly - 4

Total - 95

Teaching language

Português

Prerequisites

It’s advisable that the student get approval in basic chemistry lectures as Introduction to physical chemistry, analytical Chemistry and basic knowledge in Organic and Inorganic Chemistry.

Bibliography

Recommended book

Quantitative Chemical Analysis, D. C. Harris, W. H. Freeman; 9th edition (July 15, 2015) 

 

Notes/summaries supplied by the teacher

Teaching method

Lectures supported by data show projection of figures/plots/text included either in the documentation supplied directly by the teacher or in the recommended bibliography. Online

Problem solving sessions. Online

Computer sessions with presentation of i)linear and non-linear regression, ii) worksheet to evaluate standard deviation that affects linear regression . On line

Laboratory sessions with 5 different experiments. 50% Online and 50% Onsite (Laboratory)

Evaluation method

The continuous evaluation has 2 components: theoretical (T) and practical (L). The final classification is calculated according:

Final classification =50% x L + 50% T 

 

To get approval in the theoretical part it is necessary to obtain positive  classification in the final test or official examination.

The laboratorial classification results from:

i) the evaluation and discussion of one laboaratorial report

ii)evaluation of questionaries of the remaining experimental works

iii) laboratorial performance


Subject matter

Data analysis and statistical treatment

I Introduction to optical methods

Electromagnetic radiation : radiation -matter interaction ; Equation of energy conservation ;

Spectroscopy and regions of the electromagnetic spectrum;  associated transitions;

Units and conversions in spectroscopy

 Absorption of electromagnetic radiation, atomic absorption; Molecular Absorption ( UV , Vis , IR , Raman )

  The equipment in spectroscopy: Quantitative aspects of molecular absorption spectra UV - Vis , Transmittance, Absorbance - OD ; Lambert Law, Bee´s Law ; molar absorptivity; limitations and deviations from the quantitative analysis .

 Emission spectra, fluorescence, phosphorescence

 Infrared Spectroscopy: Concepts of electric dipole, harmonic oscillator and anharmonic revisited; modes of molecular vibrations; Examples of IR spectra and characteristic bands ;

Raman spectroscopy

II Introduction to electroanalytical methods

Notion of the electrochemical cell and its schematic representation ;  faradaic and non-faradaic current;  liquid - liquid junction potential .

Potential of an electrode : standard hydrogen electrode and other  reference electrodes; Calculation of the thermodynamic potential of an electrochemical cell ; Use of molar concentration vs. activity , the activity coefficients and ionic strength ; Calculation of activity coefficients ; notion of formal potential ; Influence of resistance in an electrochemical cell potential , polarization and its importance for studying electrochemical methods .

Potentiometry: reference electrodes ; quirks of their construction and use; Examples of calomel electrodes and silver / silver chloride ; membrane electrodes , the pH electrode .

Voltammetry: Introduction to cyclic voltammetry ; the shape of a voltammogram and concentration profiles ; reversible reactions and reversibility ; calculations of diffusion coefficients , formal reduction potential and number of electrons exchanged ; chemical reactions coupled to electrochemical processes.

III Introduction to spectrophotometric methods

IV Other Modern Analytical Methods: Confocal and Transmission Electron Microscopy.