Intrumental Methods of Analysis II

Code:

MI072218

Acronym:

MIA2

Keywords
Classification	Keyword
OFICIAL	Physical Sciences

Instance: 2022/2023 - 2S

Active?	Yes
Responsible unit:	Applied Chemistry Laboratory
Course/CS Responsible:	MSc in Pharmaceutical Sciences

Cycles of Study/Courses

Acronym	No. of Students	Study Plan	Curricular Years	Credits UCN	Credits ECTS	Contact hours	Total Time
MICF	194	Official Curriculum	2	-	6	52	162

Teaching language

Portuguese

Objectives

AIMS:

This curricular unit shares the objectives already identified in the previous curricular unit of Instrumental Methods of Analysis I. In particular, it intends to:

 

- prepare the trainee to use the most common laboratory instrumentation to assess the quality of chemical/biological substances and their effects, whether in a research context, in scale production with quality criteria, of simple follow-up of laboratory application in clinical trials, or in the service of public health;

 

- to prepare excellent pharmaceutical professionals with critical capacity regarding scientific information of experimental origin;

 However, in a distinctive way, the focus is placed: - in electrochemical techniques, which are widely used either in compendial volumetric procedures for quantifying raw materials for the preparation of medicines, or in the sensory form of medical devices useful for different chronic pathologies;

 

- in the consolidation of thermodynamic and kinetic concepts underlying electrochemical techniques, such as charge transport and the formation of interface potentials that justify, on the one hand, the redox environment, nerve conduction, flow of neurotransmitters and other signaling agents released by exocytosis; on the other, his preference for electroanalysis in the characterization of biological phenomena of cellular dynamics;

 

- in theoretical aspects and in the use of different separation techniques, as they justify the laboratory instrumentation most used in pharmaceutical control and throughout the life cycle of each medicine. Its use extends from the synthesis or isolation of active substances from a pharmacological point of view, to the detection of contamination, by synthesis intermediates, in the pharmaceutical forms available for dispensing, to the monitoring of its pharmacokinetics.

 

Learning outcomes and competences

RESULTS AND SKILLS:


The nature and ordering of theoretical and laboratory themes, intend to provide the trainee with:

- ability to decide on the selection of the most appropriate instrumental analytical techniques and methods, according to the criteria of nature, quantity and complexity of the sample;

- familiarization with laboratory analytical instrumentation;

- familiarization with sample processing procedures in different drug control contexts, including identification and contamination tests for elementary impurities (ICH Q3D);

- consolidate skills in developing and using spreadsheets for recurrent calculation of laboratory data; 

This curricular unit is among the later ones in the area of ​​chemistry taught to the future master in pharmaceutical sciences, and it is therefore expected that the student has already consolidated knowledge regarding:

- calculus, linear algebra, statistics - CU of Mathematics and Biostatistics

- the validation of instrumental procedures - Instrumental Methods of Analysis I CU

- fluid mechanics and electricity - CU of Applied Physics

- reactivity and nomenclature of organic compounds - UC Organic Chemistry

- chemical and thermodynamic equilibrium - UC of Analytical Chemistry and Physical Chemistry.

Working method

Presencial

Program

 Theoretical program:

THEME 1 (4 hours) – Introduction to electroanalysis, and its context in the pharmaceutical activity; activity vs. concentration, ionic strength, importance in chemical speciation. Reversible and irreversible electrochemical cells; rules of representation. Calculation of cell potentials from electrode potentials; relationship between potential and Gibbs free energy; Nernst's equation. Electrode polarization; faradic and nonfaradic currents in electrochemical cells. Static and dynamic electroanalytical techniques.

THEME 2 (4 hours) – Potentiometry; modified Nernst equation; potentiometric selectivity coefficient. Reference electrodes; metallic and selective membrane indicator electrodes. Net junction potential. The glass electrode. Direct potentiometric determinations and potentiometric titrations. Equipment used for the above determinations. Common applications with pharmaceutical, environmental and biochemical interest, namely in the dosing of proton and calcium, fluoride, chloride and sodium ions. Modification of electrode membranes for the determination of glucose and pharmaceutical species in various matrices.

THEME 3 (4 hours) - General aspects of conductimetry. Electrical quantities applied to charge transport to electrolyte solutions. Equivalent conductance (or conductivity), equivalent ionic conductance (or conductivity) at infinite dilution. Conductivity meters and conductivity cells. Determinations by direct conductimetry and its applicability in the control of deionized water. Conductometric titrations; acid-base titration and precipitation titration, as an alternative to classical volumetry.

THEME 4 (4 hours) – Electrogravimetry and coulometry. Methods performed at constant cell potential, controlled working electrode potential or constant current intensity. Galvanostats. Variation of current and potential intensity over time in the techniques described. Advantages of the technique performed at controlled working electrode potential. Advantages of using potentiostatic techniques. Need to use inert electrodes in electrogravimetric techniques. Use of coulometric methods, namely titrations, with the advantage of using unstable titrants, which will be generated at the time of titration. The Karl-Fisher method in pharmaceutical analysis.

THEME 5 (5 hours) – Voltametry and amperometric techniques; Clark's cell and glucometer as examples. Techniques based on varying the potential difference and measuring the resulting current intensity; diffusion and migration currents. Hydrodynamic voltammetry, differential pulse voltammetry, square wave voltammetry, cyclic voltammetry, anodic stripe voltammetry, cathodic stripe voltammetry and polarographic techniques. Methods for the determination of metallic species as well as organic compounds. Use and choice of conventional glassy carbon working electrodes, carbon nanotubes, gold or platinum or surface-modified electrodes to increase the specificity of quantitative analyses.

THEME 6 (4 hours) – Chromatography: introduction to analytical separation; chromatographic separations; main mechanisms underlying chromatographic separation processes; classification of chromatographic methods; HPLC and GS chromatographs; HPLC and GS chromatograms. General theoretical aspects: migration of mixture components; the widening of the bands (“peaks”) / column efficiency; variables that affect efficiency; obtaining the main chromatographic parameters from the chromatogram (resolution, number of theoretical plates, plate height, …). Comparison of HPLC, UHPLC and UPLC chromatography. Validation of chromatographic procedures. The importance of chromatographic techniques in modern pharmaceutical, clinical, food industry, etc. laboratories.



Laboratory program:

 The laboratory activities to be carried out do not coincide in diversity with the number of weeks available, approximately thirteen weeks. Alternatively, they are sized to maximize individualized laboratory performance. This option stems from the compromise between the high number of students enrolled annually at the UC, and the need to ensure uniformity of skills and laboratory maturity of each trainee by filling in training deficiencies that are often difficult to observe when working in groups. For this purpose, 8 works are considered:

WORK 1: Potentiometric titration. This work aims to use the glass electrode. The objective is to verify the dose of acetylsalicylic acid in a commercial drug formulation, through an acid-base volumetry with instrumental detection. The exploration of already acquired skills in the use of spreadsheets for the treatment of the experimental data obtained is encouraged, specifically in the calculation of the first and second derivatives. In a second step, familiarization with the use of automated instrumentation in the laboratory is provided, in this case using an automatic titrator for the same purpose, which allows for the comparison of results and the objective development of critical analysis skills.

WORK 2: Study of a potassium ion selective electrode (ESI) and determination of potassium content in food matrices. With this work it is intended to consolidate competences and knowledge of methodological validation (determination of application range, sensitivity, detection limit and quantification), here using electroanalytical techniques, and additionally of the advantages and limiting aspects of the use of sensors in matrixes of sample of greater complexity.

WORK 3: Determination of the fluorine dose compliance of a commercial drug formulation (elixir) by direct potentiometric analysis and by the standard addition method. With this work it is intended that the trainee is faced with the need to decide on the most appropriate instrumental methodologies in view of the challenges posed by the complexity of the sample, either by the possible interferences that affect the magnitude of the analytical signal, or by interferences capable of generate themselves an instrumental response.

WORK 4: Conductometric determination of the amount of acetic acid in a commercial vinegar and an adulterated vinegar. The aim of this work is to familiarize the student with the use of electroanalytical procedures for determining ionic content, based on the variation of conductivity and obtaining quantitative chemical information in the control of fundamental food quality from the interaction of a chemical substance with its titrant. This methodology can be applied to the chemical control of different substances present in different matrices.

WORK 5: Use of the coulometric method in the determination of thiosulfate by an amperostatic method. The aim of this work is to put the trainee with contact with one of the most advantageous instrumental methodologies for titration with unstable chemical species that are generated during the titration process. This methodology can be applied to the control of pharmaceutical processes.

WORK 6: Determination of quinine in tonic water by high performance liquid chromatography (HPLC). With this work it is intended to provide the trainee with contact with one of the most common instrumental methodologies in pharmaceutical analysis.

 WORK 7: Dose compliance in acetaminophen of a commercial drug formulation by square wave voltammetry. Use of direct analysis after calibration. The aim of this work is to familiarize the trainee with the use of this rapid analytical technique and with low consumption of the analytical sample and with the importance played by the instrumental methodology in obtaining results for the analysis and chemical control in the evaluation of the quality of medicines.

WORK 8: Communication of laboratory information. This work is intended to familiarize the trainee with the critical and rigorous use of experimental information. For this purpose, the trainee prepares, based on one of the previous works, a presentation of 10-15 minutes, which integrates the results of previous laboratory classes with the skills acquired in the theoretical-practical classes.

 

Mandatory literature

Rouessac Francis; Chemical analysis: modern instrumental methods and techniques. ISBN: 0-471-97261-4
Skoog Douglas A.; ; Principles of instrumental analysis.
Harris Daniel C; Quantitative chemical analysis
Tiago Fernandes-REIT; Titulo Teste
Poldinger Walter; Compêndio de psicofarmacoterapia

Teaching methods and learning activities

The program of “Instrumental Methods of Analysis II” is transmitted through lectures and laboratory classes. The lectures are held with the support of audio-visual equipment available. The laboratory work is conducted in groups of 2-3 students in a rotation regimen according to a timetable.

Main bibliography: Douglas A. Skoog, Principles of instrumental analysis. ISBN: 0-03-001229-5 Rouessac Francis; Chemical analysis: modern instrumental methods and techniques. ISBN: 0-471-97261-4 Daniel C. Harris, Quantitative chemical analysis. ISBN: 0-7167-4464-3.

Evaluation Type

Distributed evaluation with final exam

Assessment Components

designation	Weight (%)
Exame	80,00
Participação presencial	0,00
Trabalho laboratorial	20,00
Total:	100,00

Amount of time allocated to each course unit

designation	Time (hours)
Frequência das aulas	52,00
Total:	52,00

Eligibility for exams

Attendance to laboratory classes is  obligatory, as established in the FFUP Assessment Rules. The attendance of the students to the theoretical classes is not obligatory.

Calculation formula of final grade

The classification of the curricular unit is obtained by the weighted average of the marks obtained in the laboratory evaluation (either obtained in a distributed evaluation form, or in the practical part of the final exam), with a percentage contribution of 20%, and in the written test with a percentage contribution of 80%. The laboratory evaluation is quantified (0-20) and performed during the laboratory classes, accompanied by the delivery of reports containing the recording of experimental data and associated calculations. Students rated below 9.5 are considered failed and need to make a practical test on the final exam. The approval of the laboratory part (either in the distributed evaluation, i.e. during the practical classes or in the practical part of the final exam) is a prerequisite for admission to the student's written proof of the final exam. Students who, by law, are exempted from attending classes (and therefore cannot be subject to distributed evaluation) must be called to perform the final practical exam. The final exam includes: Practical test - covers the content taught in the laboratory component of the curricular unit. It represents the execution of a laboratory work accompanied by the elaboration of a report. The rating is on a scale of 0 to 20. In addition to the other cases foreseen by law, the practical test is intended only to students with frequency but that obtained a score lower than 9.5 in the laboratory evaluation. Written Test - Covers all matters contained in the program effectively taught. The rating is on a scale of 0 to 20. Students rated below 8.5 are considered reproved. Students with a rating equal to or greater than 8.5 are considered approved if the weighted average with the practical evaluation shows a value equal to or greater than 10.

Classification improvement

Students who want to improve their grades can do so by improving the grade obtained in the written test of the final exam.