00090 - Analytical Chemistry

Learning outcomes

The aim of the course is to provide the student with the basic knowledge of the most common quantitative analytical techniques, including both classic and instrumental methods. The student would thus be able (a) to understand the principles of such methods, (b) to select the most appropriate analytical technique for a given application, and (c) to correctly evaluate and express the quality of an analytical result.

Course contents

Statistical treatment of experimental data: errors in analytical chemistry, statistics of errors, tests of significance, error propagation, significant figures, absolute and relative analytical methods, calibration (external calibration, standard additions, internal calibration), least squares fitting, characteristics of an analytical procedure (accuracy, precision, specificity and selectivity, linearity range, detection and quantitation limits, robustness, ruggedness).

Analytical process: errors in analytical process, sampling of homogeneous and heterogeneous materials, sample treatment, sample dissolution: digestion and fusion, sample clean-up (solid-liquid and liquid-liquid extraction, SPE), reference materials.

Equilibria in solution: chemistry of aqueous solutions, systematic approach to equilibrium problems, mass balance equation, charge balance equation, ion activity and concentration, the Debye-Huckel equation, solubility and solubility product, common ion effect, effects of secondary solution equilibria: hydrolysis and complexation, effect of pH, precipitation and separation of ions.

Gravimetric analysis: the precipitation process, types of precipitates and their characteristics, homogeneous precipitation, impurities in precipitates, digestion, double precipitation, masking reagents, washing, drying and ignition, some common precipitation reactants.

Titrations: calculus for titration analysis, acid-base conjugate couples, buffer solutions, theory of acid-base neutralization titrations, strong acid-strong base titration curves, weak acid-strong base titration curves, weak base-strong acid titration curve, species in a buffer solution as a function of pH, titration curves for complex acid-base systems (strong acid-weak acid and strong base-weak base), polyprotic acids and bases, species of a polyprotic acid as a function of pH, titration curves for polyprotic acids and bases, amphiprotic species, titration curves for amphiprotic species, applications of acid-base titrations, precipitation titrations, titration curves, argentometric titrations according Mohr, Volhard and Fajans, complexometric titrations, titrations with EDTA, redox titrations, common reducing and oxidizing agents, applications of redox titrations.

Electrochemistry: redox reactions, electrochemical cells, electrode potentials, junction potentials, reference electrodes, class 0, class 1 and class 2 electrodes, potentiometry, ion-selective electrodes, glass electrode for pH measurement, combined pH electrodes, measurement of pH, glass membrane ion-selective electrodes for other cations, other ion-selective electrodes based on solid-state, liquid ion exchange and polymer membranes, cells for gas measurement, electrolysis, correlation between current intensity and cell potential, other electrochemical analytical methods (electrogravimetry, coulometry, conductimetry).

Spectroscopic methods: electromagnetic radiation, molecular absorption spectra in gaseous and condensed state (electronic, vibrational and rotational contributions), absorbance and transmittance, Lambert-Beer law, deviations from the Lambert-Beer law, analysis of mixtures, error in spectrophotometric measurements, derivative spectra, spectrophotometers (light sources, filters and monochromators, sample cuvettes, detectors, instrument configurations), fluorescence and phosphorescence, emission and excitation spectra, quantitative analysis, analyte derivatization for fluorescence detection, atomic spectrometry, atomic absorption and emission spectra, atomizers (flame atomizers, electrothermal atomizer, plasma atomizer), hollow cathode lamp, instrument configurations, spectral and chemical interferences.

Chromatographic techniques: principles of chromatographic separations, parameters of chromatographic separation, factors that affect the separation process, planar and column chromatography. Gaschromatography: principles. colum and stationary phases, instrumentation and detectors, applications. Liquid chromatography: principles and separation mechanisms, columns and stationary phases, isocratic and gradient elution, instrumentation and detectors, applications.

Readings/Bibliography

Skoog, West, Holler, Crouch – Fondamenti di chimica analitica - 2° Edizione – EdiSES (2004)

Harris - Chimica analitica quantitativa - 2° Edizione – Zanichelli (2005)

Skoog, West, Holler – Chimica analitica: una introduzione - 3° Edizione – EdiSES (1996)

Harris – Fondamenti di chimica analitica – Zanichelli (1999)

Teaching methods

The course mainly consists in lectures dealing about the basic principles of the various quantitative analytical techniques, as well as some selected applications. In addition, the notions acquired during the course will be applied to the solution of common numerical problems in analytical chemistry, in order to further illustrate practical applications of analytical techniques and improve their basic knowledge.

Assessment methods

The final oral exam includes both the solution of a numerical problem and questions about theoretical notions of analytical chemistry.

Teaching tools

Video and overhead projector. Slides of all the lectures (except as concerned the solution of numerical problems) are available, either as photocopies or PowerPoint files.

Office hours

See the website of Massimo Guardigli