3. • Qualitative analysis includes identification
of unknown substance by chemical tests
(elements, species and/or compounds
present in the sample)
• Quantitative analysis is the determination
of the absolute or relative amount of
(elements, species and/or compounds
present in the sample)
• Analyte:An element, species or compound
that is the subject of analysis
4. Scope and application:
• Analytical data are required in wide range of
disciplines and situations in pharmacy that includes
the following:
• Quality control (QC): In many manufacturing industries,
the chemical composition of raw materials, intermediates
and finished products needs to be monitored to ensure
satisfactory quality and consistency.
• Clinical and biological studies: The levels of important
nutrients, including trace metals (e.g., sodium,
potassium, calcium and zinc), naturally
producedchemicals, such as cholesterol, sugars and
urea
5. Scope and application:
• Fundamental and applied research: The
chemical composition and structure of
materials used in or developed during
research programs in numerous
disciplines can be of significance. Where
new drugs or materials with potential
commercial value are synthesized, a
complete chemical characterization may
be required involving considerable
analytical work.
6. Definitions and terminology in data
handling
• Chemical interferents: a substance which
may cause incorrect or erroneous results.
• Lower limit of detection: the lowest
concentration below which test will fail to
recognize the presence of an analyte
7. Definitions and terminology in data
handling
• Specificity: defines how a test may
respond to the presence of a particular
analyte, so if the test is totally specific then
it will only respond to the analyte of
interest and in this case no chemical
interferents will interfere with the analysis.
8. Definitions and terminology in data
handling
• Sensitivity: describes how close or similar
in magnitude two readings maybe , and
still distinguished from each other.
9. Analytical problems and
procedures:
• The most important aspect of an analysis
is to ensure that it will provide useful and
reliable data on the qualitative and/or
quantitative composition of a material or
structural information about the individual
compounds present
10. Analytical problems and
procedures:
• The most appropriate analytical technique and
method can then be selected from those
available or new ones devised and validated by
the analysis of substances of known composition
and/or structure. It is essential for the analytical
chemist to have an appreciation of the objectives
of the analysis and an understanding of the
capabilities of the various analytical techniques
at his/her disposal without which the most
appropriate and cost-effective method cannot
be selected or developed
11. Analytical procedure:
• The stages or steps in an overall analytical
procedure can be summarized as follows.
●Definition of the problem
• Analytical information and level of
accuracy required: Costs, timing,
availability of laboratory instruments and
facilities
12. Analytical procedure:
●Choice of technique and method
Selection of the best technique for the required analysis, such as chromatography,
infrared spectrometry, titration. Selection of the method (i.e. the detailed stepwise
instructions using the selected technique).
Selection of the most appropriate analytical method should take into account the
following factors
• ●the purpose of the analysis, the required time scale and any cost constraints;
• ●the level of analyte(s) expected and the detection limit required;
• ●the nature of the sample, the amount available and the necessary sample
preparation procedure;
• ●the accuracy required for a quantitative analysis;
• ●the availability of reference materials, standards, chemicals and solvents,
instrumentation and any special facilities;
• ●possible interference with the detection or quantitative measurement of the
analyte(s) and the possible need for sample clean-up to avoid matrix interference;
• ●the degree of selectivity available methods may be selective for a small number of
analytes or specific for only one;
• ●quality control and safety factors
13. Analytical procedure:
• ● Sampling:
• Selection of a small sample of the material to be
analyzed. Where this is heterogeneous, special
procedures need to be used to ensure that agenuinely
representative sample is obtained
• ● Sample pre-treatment or conditioning
• Conversion of the sample into a form suitable for
detecting or measuring the level of the analyte(s) by the
selected technique and method. This may involve
dissolving it, converting the analyte(s) into a specific
chemical form or separating the analyte(s) from other
components of the sample (the sample matrix) that could
interfere with detection or quantitative measurements.
14. Analytical procedure:
• ●Qualitative analysis
• Tests on the sample under specified and controlled conditions.
Tests on reference materials for comparison. Interpretation of
thetests.
• ●Quantitative analysis
• Preparation of standards containing known amountsof the
analyte(s) or of pure reagents to be reacted with the
analyte(s).Calibration of instruments to determine the responses to
the standards undercontrolled conditions. Measurement of the
instrumental response for eachsample under the same conditions as
for the standards. All measurementsmay be replicated to improve
the reliability of the data, but this has cost andtime implications.
Calculation of results and statistical evaluation.
15. Analytical procedure:
• ●Preparation of report or certificate of analysis
• This should include a summary of the analytical
procedure, the results and their statistical assessment,
and details of any problems encountered at any stage
during the analysis.
• ●Review of the original problem
• The results need to be discussed with regard to their
significance and their relevance in solving the original
problem. Sometimes repeat analyses or new analyses
may be undertaken.
•
16. The General Analytical Problem
Select sample
Extract analyte(s) from matrix
Detect, identify and
quantify analytes
Determine reliability and
significance of results
Separate analytes
