The document discusses various analytical techniques used in pharmaceutical analysis to identify and quantify chemical substances. It describes techniques including gravimetric analysis, titrimetry, polarimetry, refractometry, chromatography, spectroscopy, electrochemistry, kinetics methods, and hyphenated techniques. Specifically, it provides details on the principles and applications of techniques like titration, high performance liquid chromatography, UV-visible spectroscopy, infrared spectroscopy, mass spectroscopy, and hyphenated methods like LC-MS and GC-MS.

1. Analytical techniques in
Pharmaceutical analysis
By
Zafar Mahmood

2. AnalyticalTechnique:
• An analytical technique is a method that is used to determine
the identification or concentration of a chemical substance.
• There are a wide variety of techniques used for analysis, from
simple weighing (gravimetric analysis) to titrations
(titrimetric) to very advanced techniques using highly
specialized instrumentation.

3. Types of analytical techniques
The following are the various analytical techniques which are being
used in qualitative and quantitative analysis of drug substances and
drug products in a pharmaceutical industry.
• Gravimetric techniques
• Titrimetric techniques
• Polarimetry
• Refractometry
• Chromatographic techniques
• Spectroscopic techniques
• Electrochemical techniques
• Kinetic method of analysis
• Hyphenated techniques

4. Gravimetric Analysis
• Gravimetric analysis is a technique through which the amount
of an analyte can be determined through the measurement of
mass.
• Gravimetric analyses depend on comparing the masses of
two compounds containing the analyte.The principle behind
gravimetric analysis is that the mass of an ion in a pure
compound can be determined and then used to find the mass
percent of the same ion in a known quantity of an impure
compound.
Examples of gravimetric analysis are residue on ignition, loss
on ignition, ash content.

5. TITRIMETRY
•TITRATION
Measurement of the volume of a unknown solution (the analyte) with a known
concentration of a reagent(the titrant).
• DIRECTTITRATIONS
Direct titration is the treatment of a soluble substance, contained in solution
in a suitable vessel (the titrate), with an appropriate standardized solution (the
titrant), the endpoint being determined instrumentally or visually with the aid
of a suitable indicator.
The titrant is added from a suitable burette and is so chosen, with respect to
its strength (normality), that the volume added is between 30% and 100% of
the rated capacity of the burette. [NOTE—Where less than 10 mL of titrant is
required, a suitable microburet is to be used.]The endpoint is approached
directly but cautiously, and finally the titrant is added dropwise from the buret
in order that the final drop added will not overrun the endpoint.The quantity
of the substance being titrated may be calculated from the volume and the
normality or molarity factor of the titrant and the equivalence factor for the
substance given in the individual monograph.

6. TITRIMETRY (Contd.)
• RESIDUALTITRATIONS
Some Pharmacopoeial assays require the addition of a
measured volume of a volumetric solution, in excess of the
amount actually needed to react with the substance being
assayed, the excess of this solution then being titrated with a
second volumetric solution.This constitutes a residual
titration and is known also as a “back titration.”The quantity
of the substance being titrated may be calculated from the
difference between the volume of the volumetric solution
originally added, corrected by means of a blank titration, and
that consumed by the titrant in the back titration.

7. TITRIMETRY (Contd.)
• COMPLEXOMETRICTITRATIONS
Complexometric titration is a form of volumetric analysis in
which the formation of a colored complex is used to indicate
the end point of a titration.
Particularly useful for the determination of a mixture of
different metal ions in solution
• OXIDATION-REDUCTION (REDOX)TITRATIONS
A redox titration is a type of titration based on a redox
reaction between the analyte and titrant.
• Determinations may often be carried out conveniently by the
use of a reagent that brings about oxidation or reduction of
the analyte.

8. TITRIMETRY (Contd.)
• TITRATIONS IN NONAQUEOUS SOLVENTS
Non aqueous titration is the titration of substances dissolved
in solvents other than water. It provides a solvent in which
organic compounds are soluble.
The most commonly used procedure in this titration of
organic bases with perchloric acid in anhydrous acetic acid.
It is the most common titrimetric procedure used in
pharmacopoeial assays and is suitable for the titration of very
weak acids and very weak bases.

9. POLARIMETRY:
Optical rotation is the property displayed by chiral
substances of rotating the plane of polarisation of polarised
light.
REFRACTOMETRY:
The refractive index of a medium with reference to air is
equal to the ratio of the sine of the angle of incidence of a
beam of light in air to the sine of the angle of refraction of the
refracted beam in the given medium.

10. CHROMATOGRAPHICTECHNIQUES
• Chromatography is usually a technique for separating and / or
identifying the components in a mixture. It is powerful
method in industry.
• Some major types of chromatography:
Paper chromatography
Thin layer chromatography
Liquid chromatography
Gas chromatography

11. HPLC:
It is a very efficient separation technique.
HPLC is a form of column chromatography. Its frequently
used in pharmaceutical laboratory to separate component
mixture.

12. SPECTROSCOPICTECHNIQUES:
• UV-visible spectroscopy
• Fluorescence spectroscopy
• Infrared spectroscopy
• Near infrared spectroscopy
• Mass spectroscopy
• Atomic absorption spectroscopy
• Flamephotometry
• Nuclear magnetic resonance spectroscopy (NMR)

13. Spectroscopy (Contd.)
• UV-visible spectroscopy
Ultraviolet-visible (UV-Vis) spectra are derived when the interaction
between incident radiation and the electron cloud in a chromophore
results in an electronic transition involving the promotion of one or
more of the outer shell or the bonding electrons from a ground state
into a state of higher energy.
Beer’s & Lambert’s law
• Fluorescence spectroscopy
Fluorescence is the phenomenon where a molecule absorbs light
within its absorption band and then emits this light at longer
wavelengths within its emission band.This phenomenon can be used
to identify, quantify, and observe chemical activity, and it is a popular
method due to its high levels of sensitivity, simplicity, and specificity.

14. Spectroscopy (Contd.)
• Infrared spectroscopy (Vibrational)
Infrared spectrophotometers are used for recording spectra in
the region of 4000-650 cm-1 (2.5-15.4 µm)
Fourier transform spectrophotometers use polychromatic
radiation and calculate the spectrum in the frequency domain
from the original data by Fourier transformation.
Spectrophotometers fitted with an optical system capable of
producing monochromatic radiation in the measurement
region may also be used. Normally the spectrum is given as a
function of transmittance, the quotient of the intensity of the
transmitted radiation and the incident radiation. It may also be
given in absorbance.
Functional groups.

15. Spectroscopy (Contd.)
• Near infrared spectroscopy
Near-infrared (NIR) spectrophotometry is a technique
with wide and varied applications in pharmaceutical
analysis.The NIR spectral range extends from about 780
nm to about 2500 nm (from about 12 800 cm-1 to about
4000 cm-1).
NIR spectra are dominated by C-H, N-H, O-H and S-H
overtone resonances and combinations of fundamental
vibrational modes.
Qualitative & Somehow Quantitative.

16. Spectroscopy (Contd.)
• Mass spectroscopy
A mass spectrometer produces charged particles (ions) from
the chemical substances that are to be analyzed.The mass
spectrometer then uses electric and magnetic fields to
measure the mass ("weight") of the charged particles.
• Flamephotometry
The principle of flame photometer is based on the
measurement of the emitted light intensity when a metal is
introduced into the flame.The wavelength of the color gives
information about the element and the color of the flame
gives information about the amount of the element present in
the sample.
Inorganic chemical analysis to determine the concentration of
certain metal ions, among them sodium, potassium, lithium,
and calcium.

17. Atomic absorption spectroscopy
Quantitative determination of elements using the
absorption of optical radiation (light) by free atoms in the
gaseous state. Atomic absorption spectroscopy is based
on absorption of light by free metallic ions.
In short, the electrons of the atoms in the atomizer can
be promoted to excited state for a short period of time
(nanoseconds) by absorbing a defined quantity of energy
(radiation of a given wavelength). This amount of energy,
i.e., wavelength, is specific to a particular electron
transition in a particular element.

18. Spectroscopy (Contd.)
• Nuclear magnetic resonance spectroscopy (NMR)
Nuclear Magnetic Resonance (NMR) is a spectroscopy
technique which is based on the absorption of
electromagnetic radiation in the radio frequency region 4
to 900 MHz by nuclei of the atoms.
Proton Nuclear magnetic resonance spectroscopy is one
of the most powerful tools for elucidating the number of
hydrogen or proton in the compound.

19. Electrochemical techniques
Use a measurement of potential, charge, or current to
determine an analyte’s concentration or to characterize
an analyte’s chemical reactivity. Collectively we call this
area of analytical chemistry electrochemistry because its
originated from the study of the movement of electrons
in an oxidation–reduction reaction.
pH meter, conductivity meter.

20. Kinetic method of analysis
Kinetic methods trust the measurements of
concentration changes (detected via signal changes) in a
reactant (which may be the analyte itself) with time after
the sample and reagents have been mixed manually or
mechanically.
Enzyme substrate complex.

21. HYPHENATEDTECHNIQUES:
• The coupling of a separation technique and an on-line
separation technique leads to the development of
hyphenated technique. A hyphenated technique in
analytical chemistry is ‘the marriage of two separate
analytical techniques via appropriate interfaces, usually
with backup of a computer tying everything together.
• A variety of hyphenated techniques such as LC-MS, GC-
MS , LC-NMR, ICP-MS , have been applied in the analysis
of pharmaceuticals.

22. ThankYou