96177 - Analytical Chemistry (GR.A)

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: 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).

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

The course is divided into two modules:

Programme of the Module “Analytical Chemistry 1”

- 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).

Laboratory

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.

To attend the laboratory, it is requested that students have completed the compulsory course on safety at work and they have uploaded on VIRTUALE a copy of the certificate of passing the final exam.

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

List of experiments:

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.

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.

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.

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.

Spectrophotometric analysis for the determination of copper in a solution using the standard addition method. PURPOSE: to perform the quantitative determination of a metal ion by absorbance measurement upon formation of a complex, to perform a quantitative analysis by calibration with standard additions, to learn the use of volumetric flasks and pipettes for the preparation of standard solutions.

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.

Programme of the Module “Analytical Chemistry 2”

- The Analytical Process

- 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, Introduction to Microsoft Excel®, Graphing with Microsoft Excel, Safe, Ethical Handling of Chemicals and Waste.

- SI Units

- Chemical Concentrations

- Preparing Solutions

- Data treatment – 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, Systematic Error, Gaussian Distribution, 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, 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.

- Quality Assurance

The Need for Quality Assurance, Basics of Quality Assurance, Quality System (ISO 9000: 2015) and Analytical Quality Control, Reliability, Switchability, Traceability, Validation, Standard and reference material (certified and non-certified), Degree of water purity, Control standards, Control cards, Good Laboratory Practice, Qualitative and quantitative analysis, Choice and validation of an analytical method, Security measures.

- Exercises applied to the main topics.

Readings/Bibliography

Material: the material presented in class is made available to the student in electronic format on VIRTUALE.

The course material and notes taken in class are essential for the exam, as well as one of the following texts:

- 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

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

Teaching methods

Lessons will be held in the classroom. In these lessons, topics are presented and discussed, with explanatory numerical exercises executed at the blackboard. Exercises on statistical applications of analytical data. Practical tests.

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

The assessment of learning takes place through the final exam only, which ascertains the acquisition of the expected knowledge and skills through the conduct of an oral interview, the resolution of numerical problems on the entire program carried out, the completeness of the laboratory reports and the ability to discuss them during the oral exam.

The exam registration is required on Almaesami, in compliance with mandatory deadlines. Students are invited to unsubscribe if they are not interested in taking the examination. Cancellations must be made on Almaesami or, in alternative, by writing an email to the teacher.

The evaluation criterion is based on the demonstration by the student to be able to use and apply the knowledge, information and cultural tools provided by the course, with discussion of the laboratory reports. The threshold of sufficiency of learning is represented in particular by the demonstration of critical understanding and ability to discuss about the topics of the course, as well as the resolution of numerical problems.

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

Teaching tools

Video projector, PC, Internet, JOVE and You Tube videos.

Office hours

See the website of Mara Mirasoli