Different methods of analysis
Learning Objectives Different methods of analysis
At the end of this lecture, the student will be able to
• Define and classify the Different methods of analysis, different types of Titrimetric analysis
• List of apparatus used for titration process
• List the methods for expressing concentrations in volumetric analysis
• Explain different methods of volumetric titration
Different Methods of Analysis
Pharmaceutical analysis is a critical aspect of the pharmaceutical industry, ensuring the safety, efficacy, and quality of medicinal products. In this article, we will delve into the Different methods of analysis and their importance in maintaining the integrity of the pharmaceutical market.
Analytical Chemistry
– Analytical chemistry deals with separating, identifying, and quantifying the relative amounts of the components of an analyte.
– Analyte = the thing to analyzed; the component(s) of a sample that are to be determined
The role of analytical chemistry: central science
The relationship between analytical chemistry and the other sciences
Chemistry: Biological, Inorganic, Organic, Physical
Physics: Astrophysics, Astronomy, Biophysics
Biology: Botany, Genetics, Microbiology, Molecular biology, Zoology
Geology: Geophysics, Geochemistry, Paleontology, Paleobiology
Environmental science: Ecology, Meteorology, Oceanography
Medicine: Clinical, Medicinal, Pharmacy, Toxicology
Material science: Metallurgy, Polymers, Solid state
Engineering: Civil, Chemical, Electronical, and Mechanical
Agriculture: Agronomy, Animal, Crop, Food, Horticulture, Soil
Social Science: Archeology, Anthropology, Forensics
Different methods of analysis and its scope
1. Clinical analysis – Blood, urine, feces, cellular fluids, etc., for use in diagnosis.
2. Pharmaceutical analysis – Establish the physical properties, toxicity, metabolites, quality control, etc.
3. Environmental analysis – Pollutants, soil and water analysis, pesticides.
4. Forensic analysis – Analysis related to criminology; DNA finger printing, finger print detection; blood analysis.
5. Industrial quality control – Required by most companies to control product quality.
6. Bio analytical chemistry and analysis – Detection and/or analysis of biological components (i.e., proteins, DNA, RNA, carbohydrates, metabolites, etc.). This often overlaps many areas. Develop new tools for basic and clinical research.
Classification of Analytical Chemistry
Qualitative analysis
What is present?
-Determination of chemical identity of the species in the sample.
Quantitative analysis
How much present?
Determination of the amount of species or analytes, in numerical terms
Classification of Quantitative Analysis
Chemical Methods
Electrical Methods
Instrumental methods
Biological and microbiological
1. Chemical Methods
Volumetric or titrimetric methods: Quantitative analysis by measuring the volume of a reagent needed to react with a substance of interest.
Gasometric analysis: Determining the composition of a gas mixture through chemical reactions that produce measurable gases.
Gravimetric methods: Analytical techniques based on measuring the mass of a substance to determine its quantity or concentration.
2. Electrical Methods
Polarography: An electrochemical method used to study the behavior of substances through their current-voltage relationship.
Potentiometry: The measurement of electrode potential in electrochemical cells to determine the concentration of ions in a solution.
Conductometry: The measurement of a solution’s ability to conduct electricity, used for quantitative analysis of ions.
Voltametry: A technique for analyzing electrochemical reactions by measuring current as a function of applied potential.
Amperometry: A method that measures current flow in an electrochemical cell, used for sensing and quantifying specific analytes.
3. Instrumental Methods of Analysis
Spectroscopic methods of analysis: Techniques that study the interaction between matter and electromagnetic radiation to determine the composition and properties of substances.
Chromatographic techniques: Methods that separate and analyze the components of complex mixtures by exploiting their differential affinities for a stationary phase.
4. Biological and Microbiological Methods
Antimicrobial assay based on Cup plate method: A laboratory technique for evaluating the effectiveness of antimicrobial agents by measuring the inhibition zones they create when applied to a microbial culture.
Bioassay for malaria parasite: An analytical method used to determine the concentration or potency of drugs or compounds in relation to their activity against the malaria parasite.
Titrimetric Method of the Analysis: The Basic Concepts and Classification
• Titrimetry – Any method in which volume is the signal
• Titrimetry: In which we measure the volume of a reagent reacting stoichiometrically with the analyte
• Titrimetric method is also referred as Volumetric analysis
Volumetric analysis
It is a general term for a method in quantitative chemical analysis in which the amount of a substance is determined by the measurement of the volume that the substance occupies
It is commonly used to determine the unknown concentration of a known reactant
Volumetric analysis is often referred to as titration, a laboratory technique in which one substance of known concentration and volume is used to react with another substance of unknown concentration
The Basic Principles of Volumetric Analysis
• The one solution to be analyzed contains an unknown amount of chemicals
• The reagent of known concentration reacts with chemical of unknown amount in the presence of an indicator to show the endpoint
• The volumes are measured by a titration which completes the reaction between reagent and solution
• The volume and concentration of reagent used in the titration give the amount of reagent in moles
• The amount of unknown chemical in the measured volume of solution is calculated by using the mole ratio of the equation
• The amount of unknown chemical in the original sample is calculated by the amount of unknown chemical in the measured volume
Definition of Terms: Used in Analysis
Titration: It is a procedure for determining the concentration of a solution by allowing a carefully measured volume to react with a standard solution of another substance, whose concentration is known
•A + T → products
A: analyte T: titrant
Titrant: A reagent of exactly known concentration that is used in titrimetric analysis
Titrate: A test solution is one whose concentration is to be estimated
Indicator: Some substances added to which are basically organic dyes, used to detect the end point
End point
– The point at which the reaction is observed to be completed is the end point
– The end point in volumetric method of analysis is the signal that tells the analyst to stop adding reagent and make the final reading on the burette
– Endpoint is observed with the help of indicator
Equivalent point
– The point at which an equivalent or stoichiometric amount of titrant is added to the analyte based on the stoichiometric equation
Requirements in Titration
• Stoichiometric reaction
• Rapid rate reaction
• Quantitative reaction (99.9%complete at stoichiometry)
• Have a defined end or equivalence point
• Reaction should have no side reaction, no interference from other foreign substances
• Must have some indication of end of reaction, such as color change, sudden increase in pH, zero conductivity, etc
• Known relationship between endpoint and equivalence point
The Different Glass Ware Used in Volumetric Analysis
• Volumetric analysis involves a few piece of equipment:
Pipette – for measuring accurate and precise volumes of solutions
Burette – for pouring measured volumes solutions
Conical flask – for mixing two solutions
Wash bottles – these contain distille water for cleaning equipment
Funnel – for transfer of liquids without spilling
Volumetric flasks – a flask used to make accurate volumes for solutions of kn concentration
Experimental Set-up in the Laboratory
• Two solutions are used: They are prepared according to the strength as per the requirements
– The solution of unknown concentration
– The solution of known concentration – this is also known as the standard solution
• Write a balanced equation for the reaction between your two chemicals
• Clean all glassware to be used with distilled water. The pipettes and burettes will be rinsed with the solutions which are been used for the experiment
Process – The Setup
• The burette is attached to a clamp stand above a conical flask
• The burette is filled with standard solution (in this case a yellow standard solution)
• A pipette is used to measure an aliquot of the other solution whose concentration has to be determined (in this case a purple solution unknown concentration) into conical flask
• Prepare a number of flasks repeat tests
• Last, an indicator is added to conical flask
Process – The Titration
• Read the initial level of liquid in the burette and make a note of it in the lab manual
• Turn the stop cock to add the standard solution from the burette into the conical flask Swirl the flask continuously
• So that every drop of analyte reacts with titrant in presence of an indicator
• When the colour changes permanently, stop the addition of titrant read the final volume the volume change needs to be calculate (and written down). This volume is called titre
• Repeat the titration with a new flask until consecutive concordant readings are obtained
Different methods of analysis Summary:
Analytical Chemistry:
• Qualitative analysis: Determination of chemical identity of the species in the sample.
• Quantitative analysis: Determination of the amount of species or analytes, in numerical terms
• Classification: Chemical,, instrumental, Electrical Methods and Biological and microbiological
• Terms used in analysis: Titrate, titrant, end point and
• The various apparatus used for titrimetric are: Burette, pipette, conical flask, beaker, standard flask, weights, analytical balance
Different methods of analysis Frequently Asked Questions (FAQs)
Q1: What are the key parameters evaluated in pharmaceutical analysis? A: Pharmaceutical analysis assesses parameters like identity, purity, potency, and safety of pharmaceutical products.
Q2: Why is quality control important in pharmaceutical analysis? A: Quality control ensures that each batch of pharmaceutical products meets predetermined specifications, maintaining product quality and safety.
Q3: How has artificial intelligence impacted pharmaceutical analysis? A: Artificial intelligence has improved the efficiency and accuracy of pharmaceutical analysis by quickly analyzing vast datasets.
Q4: What are the regulatory requirements for pharmaceutical analysis? A: Regulatory bodies like the FDA impose strict guidelines on pharmaceutical analysis to ensure consumer safety.
Q5: How does pharmaceutical analysis contribute to patient safety? A: Pharmaceutical analysis guarantees that medications are safe and effective, ensuring the well-being of patients.
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