00090 - Analytical Chemistry

Learning outcomes

Upon completion of the course the student: - acquires the basic elements of analytical chemistry necessary for the understanding of the basic principles of the main classical and instrumental analytical techniques useful for the performance and evaluation of controls of medicaments, cosmetic products, products intended for food, mineral waters and other substances or health care devices, including through laboratory and exercise activities; - achieves a comprehensive understanding of the analytical process (starting from the choice of analytical method to the processing of results) and of the types of classical and instrumental methods of analysis, effectively and unambiguously communicating the results of the analyses conducted, as well as the knowledge and rationale behind them, to specialist and non-specialist interlocutors; - possesses the tools to be able to critically evaluate (including statistically and chemometrically) the experimental results related to the analysis and quality control of drugs and health products; - possesses the knowledge necessary to tackle courses in the following years.

Course contents

Foreword

Basic knowledge of the following subjects is presumed:

General chemistry: Chemical reactions, stochiometric coefficients. Classification of chemical reactions, Oxidation-reduction reactions, Oxidation numbers, Oxidation and reduction, Balancing of oxidation-reduction reactions, Solutions, Water as a solvent, Electrolytes and non-electrolytes, Solubility, Solubilization process, Percentage concentration, Molarity or molar concentration, Definitions of acids and bases, Acid-base systems in water, Expression of chemical equilibrium, Equilibrium constants, Autoprotolysis of water, Acid and base dissociation constants, pH of aqueous solution. The SI system.

Statistics: Mean values of a series of data, mode, median and weighted mean. Standard deviation, relative standard deviation and coefficient of variation, variance. Student t Test. Statistical decisions: null hypothesis Ho. Ways of expressing the analysis result. Reliability or confidence limits (or intervals) of true value. Application of t Test: Comparison between true and mean value, comparison between means, comparison for paired samples (measurement on the same sample, comparison for multiple or different samples). Correlation check by means of t-Test

Mathematics: Logarithms: significance, use and calculations, Calculation with exponential numbers, Quadratic equations.

Computer skills: use of spreadsheets such as MS Excel for the analysis of scientific data and creation of graphs.

PROGRAMME

The course is divided into three modules:

Module “Statistics” (Lectures, 3 CFU, 28 hours)

The Chemical-Analytical Process: Glossary. Sampling: bulk sample, sampling of solids, liquids, and gases. Sample preparation. Elimination of interferences.

Laboratory glassware.

Quantitative chemical analysis: Replicates, types of experimental error, effect of errors on replicate results. Systematic error: accuracy, origin of systematic error, constant and proportional systematic error, identification of systematic error (certified reference materials, analysis of fortified samples, analysis using a reference method). Random error: precision, origin of random error, populations, Gaussian curve and normal Gaussian curve, mean and error on the mean. Gross error. Statistics on small data sets: sample and population, sample mean and standard deviation, confidence interval and confidence level, Student’s t. Significance tests: purpose of significance tests, critical values, t-test, F-test, G-test. Calculating and reporting an analytical result. Conventions for significant figures, error in single measurements, propagation of errors, rounding.

Calculations applied to analytical chemistry: International System units of measurement—mass, weight, mole, and millimole; molar mass; relative molar mass. Solutions and their concentrations: molar concentration and analytical molar concentration; equilibrium molar concentration; percentage concentrations and their use; parts per million and parts per billion, the p-function, density, and specific gravity. Chemical stoichiometry.

Instrumental analysis: Calibration curves, construction of a calibration curve (signal, standard, blank), linear and nonlinear calibration curves, linearization of calibration curves. Regression analysis: Principles of regression analysis, linear and nonlinear regression, coefficient of determination, error in interpolated values, evaluation of the quality of a calibration line. External calibration, matrix effect. Internal calibration, internal standard. Calibration with standard addition. Characteristics of an analytical method: validation of an analytical method, standard reference materials, main characteristics of an analytical method. Quality control, intra- and interlaboratory quality control, control samples, control charts.

Module “Analytical methods” (Lectures, 2 CFU, 20 hours)

Chemical equilibria: Systematic approach to equilibrium problems; mass balance and charge balance equations; ion activity and concentration; activity coefficient; Debye-Huckel equation.

Volumetric titrations: Chemical equilibria in aqueous solution, acid - base conjugate pairs, buffer solutions. Titrations: introduction, volumetric calculations. Neutralization titrations: titration curves for strong acids and bases, titration curves for weak acids and bases, buffer solutions composition as a function of pH, preparation of buffer solutions, titration of a polyprotic acid, of a polyfunctional base, of an amphiprotic species, chemical indicators for neutralization titrations, applications of neutralization titrations.

Potentiometry: Introduction to potentiometry: junction potential, reference electrodes, indicator electrodes (metallic electrodes of first kind, of second kind and inert; ion-selective electrodes), direct potentiometric analysis, glass electrode, errors and use of glass electrode, combined glass electrodes and electrodes selective for other ions with crystalline, liquid or polymeric membrane.

Module “Analytical laboratory” (Laboratory practicals, 1 CFU, 15 hours)

The laboratory experiences will be held in groups, programmed on the basis of the laboratory’s capacity.

As concerns the teaching methods of this course unit, all students (including all the international incoming exchange students, i.e. ERASMUS) must attend Modules 1 and 2 [https://www.unibo.it/en/services-and-opportunities/health-and-assistance/health-and-safety/online-course-on-health-and-safety-in-study-and-internship-areas] online, while Module 3 on health and safety is to be attended in class or on Microsoft Teams according to the modality chosen by the teacher. Information about Module 3 attendance schedule is available on the website of your degree programme.

Each student is required to procure and wear the chemical lab coat.

FIRST EXPERIENCE - TITLE: Calibration of volumetric equipment. PURPOSE: To become familiar with the laboratory, verify that the instrumentation to be used is in optimal condition, use of the simplest statistical parameters, write a report.

SECOND EXPERIENCE - TITLE: Preparation of a buffer solution and potentiometric measurement of the pH. PURPOSE: Design the preparation of a buffer solution given pH and concentration, use the pH meter, measure the buffering capacity of the buffer solution.

THIRD EXPERIENCE - TITLE: Potentiometric titration of a strong acid and a weak acid. PURPOSE: To become familiar with the use of the burette, to produce potentiometric titration curves, to compare the titration curve of a strong acid and a weak acid

Readings/Bibliography

The PowerPoint slides shown in class will be available on “Virtuale” (https://virtuale.unibo.it) along with instructions for the laboratory exercises and for writing reports, as well as other instructional materials (e.g., PDFs of the virtual whiteboards used in class to work through the exercises, exercise texts and expected results or step-by-step solutions, self-study activities to be completed in preparation for the laboratory exercises, multiple-choice self-assessment tests, fact sheets on reagents or instruments described during lectures, etc.).

The teaching materials and notes taken during class are essential for exam preparation, as is studying one of the following textbooks:

- Fondamenti di Chimica Analitica Quantitativa", Daniel C. Harris (Zanichelli Editore, Bologna, 2017).

- "Fondamenti di Chimica Analitica di Skoog e West”, F. J. Holler, S. R. Crouch (Edizione: III, EdiSES, S.r.l., Napoli, 2015).

- “Chimica Analitica e Analisi Quantitativa”, D.S. Hage, J.D. Carr, (Piccin Nuova Libraria SpA, Padova, 2012).

- "Chimica Analitica Quantitativa", Daniel C. Harris (Zanichelli Editore, Bologna, 2017).

Other university-level analytical chemistry books can be freely chosen by the student.

The following book contains both the theoretical part and numerous exercises with detailed explanation for their execution, only for the subjects of Module “Statistics”:

"Il Laboratorio di Chimica Analitica - Concetti di base ed esercizi svolti" M. Grotti, F. Ardini (EdiSES, S.r.l., Napoli, 2022).

The following book, in which the theoretical part is only recalled to great signs, contains numerous exercises with detailed explanation for their execution:

- "Esercizi per la Chimica Analitica, con richiami di teoria", S. Araneo, (Progetto Leonardo, Esculapio, Bologna, edizioni 2012 e 2018).

Teaching methods

The course consists of two modules of lectures and one module of laboratory exercises. The lectures are held in person. During these lectures, the course topics are presented and discussed, with explanatory numerical exercises worked out by the instructors on the board. Laboratory activities include individual practical exercises, the preparation of a report, and a discussion during the exam. In the laboratory sessions, students will apply the analytical techniques learned during lectures and acquire the practical skills necessary to work in the laboratory in accordance with quality and safety principles. During lectures—particularly when exercises are performed in class—and in the laboratory, collaboration among students is encouraged through peer instruction. Homework assignments will be given to be completed before the next class, in order to reinforce learning. For each laboratory exercise, a report must be submitted in which the student, using the tools learned during the course, will analyze the results obtained to draw conclusions regarding the outcome of the exercise.

Attendance at lectures and laboratory sessions is mandatory. To take the final exam, students must attend at least 70% of the lectures and 80% of the laboratory sessions.

As concerns the teaching methods of this course unit, all students (including all the international incoming exchange students, i.e. ERASMUS) must attend Module 1, 2 online [https://www.unibo.it/it/servizi-e-opportunita/salute-e-assistenza/salute-e-sicurezza/sicurezza-e-salute-nei-luoghi-di-studio-e-tirocinio], while Module 3 on health and safety is to be attended in class. Information about Module 3 attendance schedule is available on the website of your degree programme ("studiare"--"formazione obbligatoria su sicurezza e salute").

Assessment methods

Learning assessment is based solely on the final exam, which evaluates whether students have acquired the expected knowledge and skills.

To take the exam, you must register via Almaesami, strictly adhering to the specified deadlines. A list for each of the three modules will be available on Almaesami. If you are not interested in taking the exam, please cancel your registration—preferably before the registration period closes—or, if necessary, by sending an email to the instructor.

The final grade of this course, expressed on a scale of 30, will be the average (weighted by the number of CFU assigned to each module) of the grades obtained for each module. For each module, the grade is expressed on a scale of 30.

Module “Statistics”. The Module exam is an oral discussion of the topics covered in class. The grade for this module, expressed on a scale of 30, will be assigned as follows:

Points 18-24: Knowledge of a limited number of topics covered in class, some serious errors. Analytical skills emerge only with the teacher's assistance.

Points 25-29: Knowledge of a large number of topics covered in class, ability to make independent critical analysis choices, mastery of specific terminology, some minor errors and/or some flaws in presentation.

Points 30-30L: Excellent to outstanding understanding of the subject matter, thorough presentation, full mastery of specific terminology, and ability to argue

Module “Analytical methods”. For this Module exam, students are required to bring a scientific calculator. The Module exam is an oral exam, which includes solving a numerical problem and an oral discussion of the topics covered in class. The grade for the module will be the sum of the grades obtained in the oral discussion (maximum 20/30) and in the exercise (maximum 10/30).

Oral Discussion (maximum 20/30). The oral exam will assess whether students have acquired the expected knowledge and skills. In particular, the assessment will focus on the student’s knowledge of the procedures for processing and analyzing experimental data covered during the lectures. The oral exam grade will be assigned as follows.

20 – 20L. Thorough preparation on all topics covered in the course, ability to analyze critically and make connections, complete mastery of specific terminology.

18 – 19. Knowledge of most of the topics covered in the course, ability to analyze critically, mastery of specific terminology.

15 – 17. Knowledge of a limited number of topics covered in the course, limited ability to analyze critically, use of terminology that is not always appropriate.

12–14. Preparation covering a very limited number of topics covered in the course, poor critical analysis skills, and use of incorrect terminology.

Numerical Exercise (maximum 10/30). The score assigned will take into account the correctness of the approach, the steps taken to solve the problem, the accuracy of the results obtained, and the degree of independence demonstrated by the student. 10 points: Exercise completed correctly and entirely independently, with adequate justification of the choices made and a correct interpretation of the final result. 7.5 points: Exercise completed largely independently, requiring only limited suggestions or reminders from the instructor, with any minor errors that do not compromise the correctness of the approach. 5 points: Exercise completed with significant guidance from the instructor or with minor procedural errors that indicate only a partial understanding of the topic. 2.5 points: Exercise only partially developed, requiring substantial guidance from the instructor to continue the solution or exhibiting significant uncertainty in the application of fundamental concepts. 0 points: The student is unable to approach the exercise, even with the instructor’s help, or the work is completely incorrect and lacks any elements that can be evaluated.

Module “Analytical laboratory”. For this Module exam, students are required to upload all laboratory reports (in PDF or Microsoft-compatible format) to Virtuale at least 48 hours before the exam session. The assessment includes a critical discussion of the laboratory experiments and the laboratory reports produced by the student. The assessment for Module 3 is based on the six lab reports produced by the student and their discussion during the oral exam, for a maximum total score of 30/30. The assessment takes into account: the completeness and accuracy of the reports; the proper processing, presentation, and interpretation of experimental data; the ability to relate the results obtained to the theoretical principles of Analytical Chemistry; the ability to critically discuss experimental procedures, sources of error, and the reliability of the results; and the student’s individual knowledge and understanding of the activities performed and the content presented in the reports. During the discussion, the student must demonstrate an understanding of the experimental procedures performed, the analyses carried out, and the significance of the results obtained. The ability to explain and justify the content of the reports is an integral part of the evaluation. The final score (maximum 30 points) will be assigned as follows: up to 18 points: completeness, accuracy, and quality of the six lab reports; up to 12 points: oral discussion of the reports, understanding of experimental procedures, interpretation of data, ability to justify the calculations performed, and ability to critically discuss the results obtained. Achieving the maximum score requires not only the submission of complete and correct reports, but also the demonstration of full personal knowledge and understanding of the activities carried out, the analyses performed, and the conclusions reported. The formal correctness of the reports alone is not sufficient to obtain the maximum grade.

With regard to assessment, the use of AI is prohibited. Any use constitutes a violation of academic integrity.

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.

The teachers are available for further clarification, and to verify the level of pre-exam preparation by appointment.

Teaching tools

Lectures will be delivered using a multimedia projector.

Practical laboratory sessions will take place in a teaching laboratory equipped with the necessary instrumentation.

All teaching materials used during lectures and/or required for the laboratory sessions will be made available through the University of Bologna's “Virtuale” platform (https://virtuale.unibo.it [https://virtuale.unibo.it/] ).

Students are required to print and bring to the laboratory the handouts for the practical sessions.

Office hours

See the website of Maria Maddalena Calabretta

See the website of Donato Calabria

See the website of Mara Mirasoli