37478 - Analytical Chemistry of Organic Materials

Learning outcomes

At the end of the course the student will acquire knowledge concerning evaluation criteria and application aspects related with the main analytical technique used for the characterization of the heritage organic materials as well as the sampling and sample pre-treatment procedures. At the end of the laboratory the student will acquire knowledge concerning the experimenting methods for the interpretation of chromatographic and spectrometric data in the identification and quantitation of organic components.

Course contents

The element carbon and its compounds, summary of main definitions in organic chemistry (formula, isomers, functional groups). Classification of organic materials. Basic concepts of chemical analysis in cultural heritage, aims and limits. Quantitative analysis: method performance, significant figures, types of errors, precision, trueness, calibration (standard deviation, bias, recovery, sensitivity, limit of detection). Chemical properties relevant in chemical analysis (molecular mass, polarity, volatility). Biomolecules, dyes, lipids (triacylglycerols, fatty acids, sterols, terpenes, polysaccharides, proteins, lignins) and synthetic polymers. Basic concepts of the analytical procedure. Sample treatment: solubilisation, solvent extraction (definition, solvent selection), chemical degradation (hydrolysis, methanolysis), thermal degradation (pyrolysis). Chromatography, definition, types of chromatography (liquid chromatography, reversed, normal, adsoprtion, partition, paper, column, thin layer; gas chromatography, high temperature GC), retention and selectivity, retention time, peak area, calibration; order of elution based on polarity and volatility. Mass spectrometry, types of ions, ionisation methods, mass spectra, quadrupole. Hyphenated techniques: HPLC-ESI (APCI)-MS, GC-QMS, GC-IRMS, Py-GC-MS. Strategies of identification of organic materials: relative distribution (chemical fingerprinting), compound ratios, molecular markers (examples), isotope ratios (delta notation). Confounding factors: degradation processes, mixtures, matrix effects, analytical artefacts. Literacy information, data base in bibliography search. Laboratory exercise: analysis of dyes in textiles by TLC and GC-MS, interpretation of GC-MS and Py-GC-MS data.

Readings/Bibliography

Lesson slides in IOL. Laboratory papers.

Textbook. General concepts:

J.S.Mills e R.W.White, The Organic Chemistry of Museum Objects, 1996.

Specific examples/ advanced techniques:

Organic Mass Spectrometry in Art and Archaeology. MP.Colombini, F. Modugno Eds, Wiley and Sons, 2009

Teaching methods

PRE-REQUISITE:to give the exam it is compulsory to have passed the exam of the course CHEMISTRY FOR RESTORATION

Videoprojection of power point presentation, utilization of chemical equipments, GC-MS software, database (Scopus, WebofSCience, Reaxys, MS library), laboratory exercise in groups . PC. Data base. Laboratory equipment. MS software. Concepts are illustrated by examples and case studies in the field of cultural heritage (analysis of pigments, dyes, oils, waxes, bituminous materials, gums, proteinaceous ligands, woody materials, resins, fibers in art, archaeology, diet, etc).

Assessment methods

Oral examination. The student will be required to discuss a journal article dealing with the application of chromatography to a sample of interest in the field of cultural heritage. The student will be asked to describe the analytical steps for the identification of a selected organic material by means of chromatographic techniques, starting from sample treatment to data interpretation. The knowledge of the chemical structure of the most important organic substances described in the course is mandatory. The knowledge acquired in the laboratory exercise will be also examined.

Teaching tools

Lecturing, tutorials, utilisation of data base for searching analytical methods, exercises from case study, laboratory.

Office hours

See the website of Daniele Fabbri