00090 - Analytical Chemistry

Learning outcomes

The aim of the course is to provide the student with: - the basic knowledge of Analytical Chemistry required to understand the principles of the most common quantitative analytical techniques, including both classic and instrumental methods; - the ability to select the most suitable analytical technique to solve a given analytical problem; - the ability to develop and optimize all the steps of an analytical procedure; - the ability to evaluate the performance of an analytical procedure and to assess the quality of an analytical result; - the ability to properly describe and comment an analytical procedure and correctly report an analytical result; - the ability to increase and update his knowledge through books, scientific publications and databases.

Course contents

- Statistical treatment of experimental data (10 hours): errors in analytical chemistry, statistics of errors, tests of significance, error propagation, significant figures, reporting experimental data in accordance to the error, calibration (external calibration, standard additions, internal calibration), least squares fitting, characteristics of an analytical procedure (accuracy, precision, specificity and selectivity, linearity range, LOD, LOQ, robustness).

- Equilibria in solution (6 hours): 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 (4 hours): the precipitation process, types of precipitates and their characteristics, homogeneous precipitation, impurities in precipitates, digestion, double precipitation, masking reagents, washing, drying and ignition, calculus for gravimetric analysis.

- Titrations (4 hours): titration curves, final and equivalence points, indicators and instrumental techniques for the determination of the equivalence point, calculus for titration analyses.

- Precipitation titrations (4 hours): characteristics and construction of titration curves.

- Acid-base titrations (8 hours): acids and bases, pH calculation (strong and weak acids and bases, buffers, amphiprotic species), characteristics and construction of titration curves of monoprotic and polyprotic acids and bases.

- Complexometric titrations (4 hours): EDTA, effect of pH on complexation reactions, formation constant and conditional formation constant, characteristics and construction of titration curves.

- Redox titrations (4 hours): oxidants and reductants, characteristics and construction of titration curves.

- Electrochemical analytical methods (4 hours): electrochemical cells, electrode potentials, junction potentials, reference electrodes, potentiometric analyses, ion-selective electrodes, glass electrode for pH measurement, combined pH electrodes, measurement of pH, other ion-selective electrodes, cells for gas measurement, overview on other electrochemical analytical methods.

- Spectroscopic analytical methods (8 hours): 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-based analysis.

- Chromatographic analytical methods (8 hours): 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.

Readings/Bibliography

- PowerPoint slides of lessons available on “Insegnamenti online” (http://iol.unibo.it/, access with credentials reserved for students enrolled at the University of Bologna).

- Fondamenti di Chimica Analitica di Skoog e West - J.F. Holler, S.R. Crouch - 3° Ed. (EdiSES, 2015).

- Chimica Analitica Quantitativa - D.C Harris - 3° Ed. (Zanichelli, 2017).

- Chimica Analitica e Analisi Quantitativa - D.S. Hage, J.D. Carr - 1° Ed (Piccin, 2015).

- Chimica Analitica. Una Introduzione - D.A. Skoog, D.M. West, F.J. Holler - 1° Ed (EdiSES, 1996).

- Elementi di Chimica Analitica – D.C. Harris – 1° Ed (Zanichelli, 1999).

Teaching methods

The course is organized in room lectures (supported by PowerPoint presentations) in which the course topics will be presented and discussed. In addition, the notions acquired will be applied to the solution of numerical exercises in order to deepen the theoretical concepts covered in the course, apply the acquired knowledge and show examples of chemical analyses. At the end of the course, some lessons will be dedicated to performing exercises like those proposed in the final exam.

Assessment methods

Verification of knowledge on the whole program by means of the following tests.

- Written numerical exercise consisting in the construction of a titration curve (passing this test is required to be admitted to the oral exam).

- Oral exam on the topics covered during the course, aimed at verifying the acquisition of knowledge and expected skills. In particular, the knowledge of procedures for processing and evaluating experimental data for quantitative analysis, the understanding of the basic principles and procedures of the main classical and instrumental analytical techniques, and the ability to select the most suitable technique for solving a given analytical problem will be evaluated. The evaluation will be based on the demonstration of the critical understanding of the topics and the ability to discuss them.

Teaching tools

Video projector. The teaching material (PowerPoint presentations, text of numerical exercises) will be made available to the student in electronic format on “Insegnamenti online” (http://iol.unibo.it/, access with credentials reserved for students enrolled at the University of Bologna). Such material should be printed and brought to class.

Office hours

See the website of Massimo Guardigli