96177 - Analytical Chemistry (GR.B)

Learning outcomes

At the end of the course the student will: - acquire (also through laboratory and exercise activities) the basics of analytical chemistry required to understand the principles of the most common quantitative analytical techniques, including both classic and instrumental methods, which are required for performing and evaluating quality control analyses of pharmaceutical principles and formulations - achieve a comprehensive understanding of the analytic process (from the choice of method of analysis to results elaboration and interpretation) and of the main classical and instrumental methods of analysis, being able to clearly and unambiguously communicate to specialist and non-specialist audiences the analytical results and their critical interpretation; - has the knowledge that enables him/her to critically evaluate (also employing statistical and chemometric tools) the obtained experimental results and those reported in drugs development or application studies and obtained in the quality control of medicines and health products; - has the required knowledge to deal the courses of 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, Activity and concentration, Percentage concentration, Molarity or molar concentration, Definitions of equivalent weight, 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: Experimental uncertainties and representation of measurements. Absolute and relative errors. Random and systematic errors. Sensitivity, precision and accuracy. Probability distributions. Position and dispersion indexes. Gaussian distribution. Mean, error on mean.
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.

The course is divided into three modules:

Module 1 “Fundamentals of Quantitative Analytical Chemistry and Validation of Analytical Results” (Lectures, 3 CFU, 28 hours)

The Analytical Chemist’s Job: General Steps in a Chemical Analysis
Basic Tools: The Lab Notebook, Analytical Balance, Burets, Volumetric Flasks, Pipets and Syringes, Calibration of Volumetric Glassware.
SI Units
Chemical Concentrations
Preparing Solutions
Statistics: Experimental Error, Significant Figures, Significant Figures in Arithmetic, Types of Error, Propagation of Uncertainty from, Random Error, Means, Comparison of Means with Student’s t, Comparison of Standard Deviations with the F Test, t Tests with a Spreadsheet, Grubbs Test for an Outlier, Propagation of Uncertainty from Random and Systematic Errors, Confidence Intervals.
Method validation: Accuracy, Precision, Sensibility (Limit of Detection, LOD, Limit of Quantitation, LOQ) Linearity, Recovery, Robustness, The Method of Least Squares, Calibration Curves, Dynamic range and linear (dynamic) range,
Calibration: Standard Addition, Internal Standards, Classification of standards (for atomic weights, definitive, primary, working, secondary), methods of analysis (definitive, reference, known error, unknown error), Ways to express the result of the analysis, Limits (or ranges) of reliability or trust of true value.

Module 2 “Quantitative Methods of Chemical Analysis” (Lectures, 2 CFU, 24 hours)
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, 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.
UV-Vis spectroscopy: Spectrophotometric analysis methods: electromagnetic radiation, absorption spectra in gaseous and condensed phase (electronic, rotational and vibrational spectra), absorbance and transmittance, Lambert-Beer law, deviations from the Lambert-Beer law, analysis of mixtures, spectrophotometric error, spectrophotometry instrumentation (sources, filters and monochromators, sample cells, detectors, instrument configurations).
Exercises applied to the main topics.

Module 3 “Laboratory of Analytical Chemistry” (Laboratory practicals, 1 CFU, 15 hours)

The laboratory experiences will be held in groups, programmed on the basis of the rules on the sanitary situation.

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 [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.

List of experiments:
1) Gravimetric calibration of micropipettes and laboratory glassware; preparation of solutions. PURPOSE: To become familiar with the laboratory and with the devices for weighing and for dispensing known volumes, to verify that the instrumentation to be used is in optimal condition, to use the simplest statistical parameters (calculation of the confidence interval, application of the t test of Student), to write a report.
2A) Calibration. Preparation of dilutions and spectrophotometric measurements. PURPOSE: To become familiar with known volume dispensing devices and spectrophotometric measurements, to apply linear regression using the least squares method, to acquire an absorption spectrum and select the wavelength for quantitative applications.
2B) Indicator. Evaluation of the color change of colorimetric indicators as a function of pH by preparing their solutions within a pH range that either corresponds to or does not correspond to the indicator’s color-change range. PURPOSE: To observe the behavior of a chemical indicator at different pH values within its color-change range or outside that range; to evaluate how the color-change range depends on the indicator’s pKa value; and to determine how this influences the selection of a chemical indicator for a specific neutralization titration.
3) Buffer. Preparation of buffer solutions, calibration of the pH meter, potentiometric measurement of pH. PURPOSE: To prepare buffer solutions, to verify their buffer capacity, to calibrate and correctly use the pH meter.
4A) Potentiometric titration. Titration of a weak acid and construction of the titration curve by potentiometric measurement of pH. PURPOSE: To become familiar with volumetric titrations, to observe and comment on the trend of the titration curve based on the experimental conditions.
4B) Standardization of the titrant by titration of a primary standard. PURPOSE: To design the titration according to the requirements provided by the teacher, to correctly apply the standardization procedure of the titrant and to process the final result by statistical methods.

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:

- Quantitative Chemical Analysis, by Daniel C. Harris, Charles A. Lucy

- Analytical Chemistry and Quantitative Analysis, by David S. Hage, James R. Carr

- Fundamentals of Analytical Chemistry, by Douglas A. Skoog, Donald M. West, F. James Holler, Stanley R. Crouch

Students are free to choose other university-level analytical chemistry textbooks.

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.

Homework assignments will be given to be completed before the next class, in order to reinforce learning.

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.

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.

During lectures—particularly when exercises are performed in class—and in the laboratory, collaboration among students is encouraged through peer instruction. 

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, 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 1. For the Module 1 exam, students are required to bring a scientific calculator. The Module 1 exam is a written exam consisting of numerical problems, multiple-choice questions, and open-ended questions on the topics covered in class. Students have 2 hours to complete the written exam. During the exam, the use of a scientific calculator is permitted; however, the use of other reference materials—such as textbooks, notes, or electronic devices—is not permitted. The exam paper will indicate the points assigned to each question, up to a maximum of 30/30. For each multiple-choice question: the maximum points for the question will be awarded for a correct answer; −1 point will be deducted for an incorrect answer; 0 points will be awarded if no answer is provided. For each open-ended question: the maximum score for the question will be awarded for a correct, complete, and adequately reasoned answer; 50% of the maximum score for the question will be awarded for an essentially correct but incomplete or partially developed answer; −1 point will be deducted for an incorrect answer or one that demonstrates a substantial lack of understanding of the required topics; 0 points will be awarded if no answer is provided. For each numerical exercise: points will be awarded based on the correctness of the approach, the step-by-step procedure, the application of theoretical principles, and the final result: 100% of the available points: exercise completed correctly and completely, with a correct procedure and an exact final result; 75% of the total score: the problem is correctly set up and solved, with minor errors in calculation, rounding, or transcription that do not compromise the correctness of the procedure; 50% of the total score: the problem is essentially set up correctly, but contains calculation or procedural errors that lead to a partially incorrect result; 25% of the total score: the problem is partially solved, with a correct but incomplete initial approach or with significant conceptual or procedural errors; 0 points: the problem is not attempted or is attempted in such a way that it contains no elements that can be evaluated.

Module 2. For the Module 2 exam, students are required to bring a scientific calculator. The Module 2 exam is an oral exam, which includes solving a numerical problem and an oral discussion of the topics covered in class. The final grade for the course 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 – 19/30. Knowledge of most of the topics covered in the course, ability to analyze critically, mastery of specific terminology.
15 – 17/30. Knowledge of a limited number of topics covered in the course, limited ability to analyze critically, use of terminology that is not always appropriate.
12–14/30. 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 3. For the Module 3 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 teacher is 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).

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

Office hours

See the website of Mara Mirasoli

See the website of Martina Zangheri