B2150 - Analytical Chemistry of Pollutants

Learning outcomes

The aim of the course is to provide the student with the basic knowledge of the most common analytical techniques for the analysis of inorganic ions, natural substances, metabolites, and toxicants in environmental matrices. In addition to room lectures, such knowledge will be also acquired by single-seat laboratory exercises and computer exercises for the processing and interpretation of experimental data. In particular, the student will be able to understand the information provided by the most common analytical techniques and define a correct procedure for chemical analyses and reporting of results.

Course contents

Room lectures (3 CFU, 24 hours)

- Instrumental analysis, calibration, and validation (8 hours). Instrumental analysis and calibration curves, construction of a calibration curve, linearization of calibration curves, principles of regression analysis, determination coefficient, error on interpolated values, evaluation of the quality of a calibration curve, calibration methods (external calibration, internal calibration, calibration with standard addition), validation of an analytical method, characteristics of an analytical method (accuracy, precision, specificity and selectivity, linearity, dynamic interval, LOD, LOQ, robustness), control samples, laboratory quality control, control charts.

- Instrumental analytical techniques (8 hours): Spectroscopic analytical methods: atomic and molecular spectra, quantitative analysis (Lambert-Beer law), molecular absorption spectroscopy, instrumental configurations, molecular emission spectroscopy, spectrofluorimeters, quantitative analysis, turbidimetry and nephelometry, atomic spectroscopy, atomization and atomizers (flame, electrothermal and plasma), absorption, emission and mass spectrometry detection techniques. Potentiometry: ion-selective membrane electrodes, glass pH electrode, ion-selective electrodes for other ions, gas probes. Chromatography: chromatographic techniques, theory of chromatography, qualitative and quantitative analysis, gas chromatography – GC (carrier gas, injection system, columns, detectors, gas-liquid and gas-solid chromatography, programmed temperature separation), high performance liquid chromatography – HPLC (mobile phase, pumps, injection system, columns, detectors, types of liquid chromatography, elution gradient separation).

- Analysis of pollutants (8 hours). Basics and characteristics of the main classes of pollutants: production, transport, distribution, bioaccumulation, sampling, and sample storage procedures. Water quality parameters and measurement techniques: dissolved and suspended solids, dissolved oxygen, BOD, COD, pH, conductivity, hardness, common inorganic ions. Volatile organic pollutants: sample treatment (static and dynamic headspace extraction, solid phase microextraction), gas chromatographic analysis. Semivolatile and nonvolatile organic pollutants: sample treatment (liquid-liquid extraction, solid phase extraction, solid-liquid extraction, microwave-assisted extraction, accelerated solvent extraction,), HPLC analysis. Metals: sample treatment (liquid-liquid extraction, solid phase extraction, gaseous hydride extraction, calcination, humid digestion, microwave-assisted digestion, speciation analysis), atomic spectroscopy, spectrophotometry, electrochemical techniques. Atmospheric pollutants: sampling techniques for atmospheric pollutants (active and passive sorbent systems, particulate and wet/dry deposition sampling systems), long-range monitoring systems, direct chemical analysis of particulate.

Practical and laboratory exercises (3 CFU, 36 hours)

- Practical exercises. Basics on Microsoft Excel. Use of Excel for data processing, data graphing, drawing and linearization of calibration curves. Use of Excel for writing laboratory reports.

- Laboratory exercises. Spectrophotometric determination of nitrite, spectrophotometric determination of iron ion using standard addition, turbidimetric determination of sulphates, spectrophotometric determination of phosphate in 96-wells microtiter plate, potentiometric determination of the ammonium ion, determination of endocrine modulators by high-performance liquid chromatography (HPLC).

Readings/Bibliography

PowerPoint slides of the lectures, supplementary teaching material (e.g., insights, films, exercises, quizzes), material for exercises in computer room, instructions for laboratory exercises and for writing reports will be available on "Virtuale" (https://virtuale.unibo.it, access with credentials reserved for students enrolled at the University of Bologna).

Suggested textbooks

- 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 Ambientale - C. Baird, M. Cann - 3° Ed (Zanichelli, 2013).

- Le analisi chimiche ambientali. Dal campionamento al dato - G. Biagio - 1° Ed. (Hoepli, 2020)

Teaching methods

During the lectures the topics of the course will be presented and discussed, with theoretical insights and application examples. The practical exercises will allow to apply the acquired knowledge to the interpretation of experimental data (e.g., data processing, construction of calibration curves, application of different calibration methods). The single-seat laboratory exercises are designed to allow each student to acquire the knowledge of some instrumental analytical techniques used in environmental analysis and the necessary skills for working in a laboratory according to quality and safety guidelines. Laboratory exercises include the analysis of unknown samples. The student will process the results obtained in the laboratory using the tools learned in the course and will submit reports with the analysis of the data and the concentration of his unknown sample. Attendance at laboratory exercises is mandatory (at least 80% of the experiences must be carried out).

Due to the type of activity, the attendance of the laboratory requires the performance by the student of the specific training on safety and health in study places (modules 1 – 3). Modules 1 and 2 are in e-learning mode, while information on dates and methods of attendance of module 3 can be found in the specific section of the degree program website.

Assessment methods

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

- Oral exam on the topics covered during the course, aimed at verifying the acquisition of knowledge and expected skills. In particular, the knowledge of calibration procedures employed in instrumental analytical chemistry, the understanding of the basic principles and procedures of the main instrumental analytical techniques for environmental analysis, the knowledge of the sampling, treatment and analysis procedures regarding the measurement of pollutants in the most common environmental matrices (air, water, soil) will be evaluated. Evaluation will be based on the demonstration of the critical understanding of the topics and the ability to discuss them.

- Evaluation of the laboratory exercises conducted based on the reports submitted by the student. For such evaluation, both the correctness of the procedures used for the elaboration of the experimental data and the concordance of the obtained results with the real concentrations of the unknown samples will be considered. The submission of the laboratory reports according to the modalities that will be explained during the laboratory is mandatory to be admitted to the final exam.

The overall mark will be the sum of the marks obtained in the oral exam (maximum 20/30) and in the laboratory exercises (maximum 10/30).

The final mark of the "Chemistry of Pollutants (C.I.)" course will be the average of the marks obtained in this course and in the "Chemistry of Organic Pollutants" one.

Teaching tools

Video projector, computer room, analytical laboratory equipped with the necessary instrumentation for performing single-seat instrumental analysis. The teaching material will be available on “Virtuale” (https://virtuale.unibo.it, access with credentials reserved for students enrolled at the University of Bologna).

Office hours

See the website of Donato Calabria