Lectures and laboratory practice on: 1. Sampling techniques of atmospheric aerosol, sample treatment (mineralization, analyte extraction), blank check. 2. Chemical analysis of collected samples by IC, F-AAS, GFAAS, ICP-AES e ICP-MS. Morphological and mineralogical analysis by SEM-EDS and elemental composition analysis by PIXE and XRF (lectures). 3. Performances of analytical methods. Certified Reference Materials. 4. Final report on the laboratory exercises.
For a discussion of the used analytical techniques:
Holler, Skoog, Crouch, “Chimica Analitica Strumentale”, EdiSES;
Skoog, Leary, “Chimica Analitica Strumentale”, EdiSES;
Cozzi, Protti, Ruaro, “Analisi Chimica Strumentale” Vol. a,b,c, Zanichelli;
Bauer, Christian, O’Reilly, “Analisi Strumentale”, Piccin
For the study of atmospheric aerosol:
Brimblecombe, “Air Composition and Chemistry”, Cambridge University Press
Learning Objectives
Principles of the most widespread advanced analytical techniques (IC, FAAS, GFAAS, ICP-AES, ICP-MS) and their application to the measurement of ions, metals and elements at concentration levels from ppm to ppt in real samples. Sample treatment. Selective extractions. Control of potential contamination by handling and laboratory environment.
Application of acquired knowledge to a case-study: determination of major and trace components of atmospheric aerosol and use of chemical markers for the characterization of its emission sources and transport processes.
Skills acquired (at the end of the course):
Ability to manage independently the chemical analysis of inorganic components in environmental samples by instrumental techniques. Ability of carrying out sampling, treatment and storage of environmental matrices minimizing the contamination risk. Quality check of analytical data.
Prerequisites
Courses required: Analytical Chemistry II and Laboratory of Analytical Chemistry II.
Oral examination.
The report of the exercises carried out in laboratory (to be delivered at least e few days bifore the oral examination) will be taken into account for the final student evaluation.
Course program
The course is focused on the learning of advanced analytical techniques for the measurement of inorganic components (ion composition, heavy metals, elements, speciation) and their application to the analysis of real environmental matrices.
The course is arranged in lectures and laboratory exercises dealing with the following topics:
1. Sampling of real matrices. Sampling techniques for gaseous, liquid and solid components. Sample storage. Procedures for minimizing the contamination risk during sampling and conservation.
2. Sample treatment; sub-sampling. Decontamination. Selective separation of analytes. Processes of matrice removal or reduction. Extraction. Mineralization. Pre-concentration processes. Control of contamination durino sample treatment. Check of blanks.
3. Chemical analysis by using advanced analytical techniques: Ion Chromatography (IC), Atomic Absorption Spectrophotometry with flame (F-AAS) and graphite furnace atomization (GF-AAS) equipped with hydride generation devices, Atomic emission spectrophotometry with inductively coupled plasma with optical (ICP-AES) and mass (ICP-MS) detector, system of X-rays Fluorescence Emission (PIXE, XRF). Surface analysis systems: SEM-EDS (Scanning Electron Microscopy – Energy Dispersive Analyses of X rays).
4. Evaluation of the performances of analytical methods. Reproducibility, accuracy, detection limit, sensitivity, selectivity. Use of Certified Reference Materials. Regulations on guide and limit values for environmental samples.
Laboratory practice: 1. Sampling of wet and dry depositions (e.g. atmospheric aerosol, dust) at local scale. 2. Treatment of collected samples. Digestion by micro-wave system. Extraction of soluble and/or available fractions by using ultrasonic bath. Resuspension and collection of insoluble dust for surface analysis. 3. Analysis of sample extracts for IC, F-AAS, GF-AAS, ICP-AES and ICP-MS. 4. Evaluation of analytical performances of used methods through determination of reproducibility, sensitivity and detection limit. 5. Final report on performed laboratory exercises (followed analytical protocols and results obtained from the measurements on real samples).