67031 - Instrumental Analytical Chemistry and Laboratory Laboratory

Course contents

Knowledge and Understanding

By the end of the course, students will know:

• statistical methods for handling error, the main significance tests, techniques for constructing calibration functions, the definitions of detection and quantification limits and their application to instrumental analytical determinations;
• the principles of partition equilibria and of separation processes;
• the operating principles and instrumental configurations of the most common analytical instruments (potentiometers, conductometers, gas chromatographs, HPLC, UV–Vis spectrophotometers, and atomic absorption spectrometers);
• the parts and structure of an analytical report.

Students will understand:

• the role of chemical equilibria (acid–base, coordination, redox, and partition) in the removal of interferences;
• the role of partition equilibria in chromatographic processes;
• the role of UV–Vis electromagnetic radiation in generating analytical signals;
• the issues associated with performing direct and indirect potentiometric measurements (relation between measured potential and analyte activity, calibration curve, detection limit);
• the relationship between conductivity measurements of a solution and the quantitative determination of one or more ionic species.

Skills and Competences

By the end of the course, students will be able to:

• prepare an analytical report;
• construct and use calibration curves, including non‑linear ones;
• recognize when it is necessary to use the standard additions method for quantitative analyte determination;
• correctly interpret measurements obtained from an analytical determination;
• identify the elements of the “analytical process” within an analytical procedure;
• assess the quality of an analytical method in relation to its objective;
• compare and critically evaluate the performance of different analytical approaches for the same sample;
• design analytical determinations in simple matrices, selecting the most suitable procedures and instrumentation.

Course Topics

• Description of the phases of the analytical process. Main components of an analytical instrument. Brief overview of sampling, collection, and sample preservation issues. The “analytical report” and the “laboratory report.”
• Statistics of instrumental analysis. Signal‑to‑noise ratio. Effect of digital sampling on the response. Calibration curves and regression equations. Standard addition. Confidence interval of a concentration derived from a calibration line and via the standard addition method. Detection limit and sensitivity in instrumental chemical analysis. Quantification limit. Error in the analytical process.
• Partition equilibria between phases. Liquid–liquid extraction. Extraction percentage. Effect of secondary equilibria on partitioning and their use for species isolation. Principal solvent extraction techniques.
• Theoretical basis of chromatographic separations, counter‑current extraction. Mechanism of column chromatographic processes. The phenomenon of chromatographic band broadening and phenomenological justifications: plate theory and kinetic theory. Instrumental chromatographic techniques: gas chromatography and high‑performance liquid chromatography (HPLC). Evaluation of column efficiency. Main chromatographic parameters. Quality of chromatographic separations. Qualitative analysis: relative retention time and Kovats retention indices. Quantitative analysis methods in chromatography. Characterization of chromatographic phases (Rohrschneider–McReynolds indices). Brief overview of solid‑phase extraction and purification (SPE, SPME).
• Electrochemical techniques. Electrical conductivity of electrolyte solutions. Specific conductivity, equivalent conductivity, and conductivity at infinite dilution. The conductometer and its use. Direct conductivity measurements. Conductometric titrations (acid–base, precipitation, complexometric). Ion‑selective and reference electrodes. Potentiometric methods with ion‑selective and metallic indicator electrodes. The Gran method for detecting the titration endpoint.
• Molecular absorption spectrometry in the UV–Vis region: principles, instrumentation, operational conditions, and quality control of spectrophotometric measurements. Construction of the instrument response curve and the Bouguer–Lambert–Beer law. Analysis of mixtures. Flame atomic absorption spectrometry. Principles, instrumentation, hollow‑cathode lamps, Boltzmann law. Qualitative and quantitative methods in flame analysis.

The course includes at least one laboratory experience integrating multiple analytical techniques, whose design will be partly entrusted to students under instructor guidance.

Note: Adequate exam preparation also requires study of the textbooks. Specific chapters from the listed manuals will be indicated for each topic, from which students may freely choose. The content in the textbooks is an integral part of the course materials.

PREREQUISITES

Generally useful knowledge and skills are those acquired in the courses: Mathematics, Physics, General Chemistry, Physical Chemistry 1, and Analytical Chemistry with Laboratory.

In particular, students should be able to:

• apply, in moderately complex contexts, the principles of chemical equilibrium and understand their effects on chemical processes;
• graphically and mathematically represent situations involving multiple simultaneous chemical equilibria;
• perform stoichiometric calculations of moderate complexity;
• possess basic notions of optics and algebra;
• handle simple mathematical functions;
• correctly plot experimental trends on Cartesian graphs;
• use spreadsheets and know their main functions;
• know the nomenclature of common organic and inorganic compounds;
• be skilled in using laboratory glassware and performing volumetric titrations

Readings/Bibliography

There are many well done books useful to deal with the contents of the course

1. D.C. Harris, Chimica Analitica Quantitativa, Zanichelli, (2017)
2. M.Castino, E. Roletto, Statistica applicata. Trattamento dei dati per studenti universitari, ricercatori e tecnici. Piccin, 1999 (ISBN: 9788829909353)
3. J.C. Miller and J.N. Miller, Statistics and Chemometrics for Analytical Chemistry, 6th ed., Prentice Hall (UK), 2010
4. D.A. Skoog, D.M. West, F.J. Holler, S.R. Crouch, Fondamenti di Chimica Analitica, III Ed., Edises, 2009
5. David Harvey, Modern Analytical Chemistry, McGraw-Hill Education, [https://www.bookdepository.com/publishers/McGraw-Hill-Education-Europe] 1999

The textbook by Harvey (4) is available in the web: (last check 20 February 2023): http://dpuadweb.depauw.edu/harvey_web/eTextProject/AC2.1Files/AnalChem2.1.pdf

Teaching methods

Lectures are accompanied by parallel experimental activities, organized in small work groups and guided by instructors, based on case studies addressing course topics through active evaluation and adaptation of simple analytical methods applied to real samples.

Each group will be assigned an analytical problem and asked to draft an analytical procedure, which will then be applied and tested in the laboratory.

Intensive laboratory work will be carried out by each group over one or two weeks (typically in May). The planned approach requires preparatory work by each group before entering the laboratory. All necessary materials and methodologies will be provided to each group for drafting the analytical procedures.

All teaching materials (lecture slides, worksheets, exercises, and supplementary materials) are shared on the "Virtuale" platform.

 

SAFETY IN STUDY AND WORK ENVIRONMENTS

Due to the types of activities and teaching methods adopted, participation in this course requires completion of Modules 1 and 2 in e‑learning mode and attendance at Module 3 on specific safety and health training. Details on Module 3 dates and attendance procedures are available in the course website section.

Assessment methods

The assessment of learning takes place through two components: laboratory activity and a final written exam.

Please note that the laboratory activity (certified by a final report signed by all group members) is compulsory, as it constitutes an integral part of the course.

The report is a group effort. It must be prepared at the end of the laboratory work and submitted within one week of its completion, as it contributes to the final grade. Detailed instructions and the evaluation rubric are available on the Virtuale platform. In particular, the report must clearly present the key aspects of the work performed, the data obtained, and the final results, accompanied by an appropriate statistical analysis.

The written exam consists of three parts:

1. A first section of true/false (T/F) and multiple-choice (MC) questions;

2. A second section of questions testing the skills acquired in the laboratory;

3. A third section composed of problems and open-ended questions.

The final laboratory grade will take into account both the group report (30% weight) and the second section of the written exam (70% weight).

The questions in the first and third sections involve solving problems and exercises related to the theoretical, practical, and applied content of the course. The exam may also include questions on prerequisite knowledge not explicitly covered during the course but essential for understanding its content.

The first section is considered passed if a score of at least 40% of the maximum possible in that section is achieved. Passing this first section (T/F and MC questions) is required to proceed to the second and third sections of the exam.

During the second and third sections, the use of a textbook (non electronic version) of the student’s choice is permitted. It is mandatory to bring a calculator (tablet or phone calculators are not allowed) and any tools needed to draw, if required, on graph paper (pencils, ruler, set square, eraser, sharpener). The materials on which to write the exam (protocol sheets, graph paper, etc.) will be supplied by the instructors.

The evaluation of the first and third sections of the written exam contributes 60% to the overall written-exam grade.

The weighted average of the laboratory grade (report plus second exam section, 40% weight) and the written-exam grade (first and third sections, 60% weight) determines the final grade.

Example:

• Report grade: 30

• Second section exam grade: 26

• First and third sections exam grade: 20

Laboratory grade: (30 × 0.3 + 26 × 0.7) = 27.2
Final grade: 27.2 × 0.40 + 20 × 0.60 = 10.88 + 12.00 ≈ 23

Once passed, the exam remains valid—at the student’s discretion—for all examination sessions in the academic year in which the course was taken. It becomes void, however, upon submission of a subsequent session’s script for grading. A maximum of two passed evaluations may be declined. A second attempt is allowed only if at least 15 days have elapsed since the previous one, unless otherwise permitted by the instructors. No more than two attempts are permitted per exam call (even if more sessions are scheduled).

Students with learning disorders and\or temporary or permanent disabilities

Please, contact the office responsible (https://site.unibo.it/studenti-con-disabilita-e-dsa/en/for-students ) as soon as possible so that they can propose acceptable adjustments. The request for adaptation must be submitted in advance (15 days before the exam date) to the lecturer, who will assess the appropriateness of the adjustments, taking into account the teaching objectives.

 

 

Teaching tools

The primary teaching support consists of deepening the lecture content through specialized textbooks, some of which are listed in the bibliography.

All teaching materials produced by the instructors (slides, worksheets and supplementary readings, exercises) will, in any case, be made available on the “Virtuale” platform.

Portions of the planning and design activities for the laboratory experiences may be carried out on the Teams platform.

Office hours

See the website of Sergio Zappoli

See the website of Andreas Stephan Lesch

See the website of Erika Scavetta