Instrumental method of chemical analysis ,Glass electrode,Single beam Spectrometers, Instrumentation of Gas liquid Chromatography

2. Instrumental Methods
Vs Non-instrumental
Methods
MIMP For Theory Exam (5Marks)
Advantages ? Disadvantages?

3. Advantages of
Instrumental Methods?
Disadvantages of
Non-instrumental
Methods?

4. Points Instrumental
Methods
Non-
instrumental
Methods
1 Handling Easy to handle Difficult to
handle
2 Result More accurate
& reliable
Less
accurate
3 Time
period
Requires less
time period
Comparativel
y, more time
period
Result Time period

5. About samples?
1. Quantity/ Amount of
Sample
2. Wastage of Sample
3. Complex samples
4. Poisonous or carcinogenic
samples
5. Coloured, turbid and
colloidal samples

6. Points Instrumental Methods Non-instrumental
Methods
4 Amount of
sample
Small quantities of
sample ( in micro
scale) can be analyzed
by this method.
Large quantities of
sample ( in macro scale)
can be analyzed by this
method.
5 Wastage of
sample
Mostly, sample cannot
be wasted &
sometimes, it can be
recovered.
Generally, sample can
be wasted & it is difficult
to recover.
6 Complex
samples
Generally, complex
samples can be
analyzed by using this
method.
Generally, complex
samples cannot be
analyzed by using this
method.
7 Poisonous or
carcinogenic
samples
Poisonous or
carcinogenic samples
can be analyzed.
Poisonous or
carcinogenic samples
cannot be analyzed.
8 Coloured,
turbid and
colloidal
samples
Such solutions can be
analyzed by using this
method.
Such solutions cannot
be analyzed by using
titration method.

8. About Advanced Technology?
1. Advanced Facilities
2.Uses in qualitative &
quantitative methods
3.Monitoring Reactions

9. Points Instrumental Methods Non-instrumental
Methods
9 Advanced
facilities
Most of instruments are
now compatible with
printer and other
devices. So, data can be
stored, printed and
managed easily. e.g.
GCMS
Such facilities are not
available.
10 Used in
qualitative
&
quantitative
methods
Generally, it is used for
quantitative
measurements.
Generally, it is used for
qualitative method
because results obtained
are less accurate.
11 Monitoring
the
reactions
It is used to monitor the
reactions. e,g, pH meter
is used to monitor rate
of corrosion by
measuring the pH of the
medium in which the
metal is present.
It is not used to monitor
the reactions.

10. Advantages of
Non-instrumental
Methods?
Disadvantages of
Instrumental Methods?

11. Points Instrumental Methods Non-instrumental
Methods
1 Cost It is expensive method
because cost of
instrument /equipment
is high.
It is not expensive method
because cost of glassware
used is low.
2 Special
Training
Special Training is
required to operate the
instrument properly.
Special Training is not
required.
3 Calibration
or
Standardizat
ion
Calibration or
standardization of the
instrument is required
before analyzing the
samples.
e.g. pH-meter is
standardized by using
buffer solutions.
Calibration or
standardization is not
required.
4 Sensitivity
and
Accuracy
Sensitivity and accuracy
depends on the
instrument used.
Sensitivity and accuracy
depends on expert person.
Space for Instrument ?

12. Glass Electrode

14. Principle, Construction & Working
of Glass Electrode MIMP (6M)
Diagram of Glass electrode: (2Mark)

15. The electrochemical cell formed is represented as
given below: (1Mark)
•Principle : (1Mark)
•Construction : (1Mark)
•Working: (2Mark)

17. Advantages of Glass electrode: (2POINTS FOR 1M)
•Glass electrode is very simple to operate.
•It can be used in portable and therefore extensively used in chemical,
industrial, agricultural and biological laboratories.
•By using glass electrode, accurate results are obtained between pH
range 1 to 10. However, by using special glass electrodes, pH up to 14 can
be measured.
•It is not poisoned easily.
•It is unaffected by oxidation – reduction potentials.
•The glass electrode can be used to measure pH
a) in the presence of strong oxidizing and reducing solutions,
b) of coloured, turbid and colloidal solutions.
c) of poisonous or carcinogenic samples.
Disadvantages / Limitations/ Drawbacks of glass
electrode: (2POINTS FOR 1M)
•Calibration or Standardization is required every time when it is to be
used.
•The glass bulb is very fragile / sensitive and hence great care is required
for its use.
•It does not function properly in some organic solvents like pure alcohol,
pure acetic acid, gelatin etc.
•It cannot be used with ordinary potentiometers but it can be used with
electronic potentiometers.
•The glass electrode has high electrical resistance.

18. Applications of pH metry: (3M Or 4M )
•The pH of number of test or sample solutions can
be measured accurately and in quick time.
•The pH of coloured solutions, colloidal solutions,
viscous protein media, complex and poisonous
solutions can be determined.
•The equivalence point of acid-base titration in
non-aqueous medium can be determined.
•pH meters are widely used to monitor the pH of
water in domestic water supply.
•pH meters are also used in almost all industries to
measure the pH.
•pH meters are also used to monitor the rate of
corrosion by measuring the pH of the medium in
which the metal is present.

19. SPECTROMETRY
Laws Of Spectrometry:
IMP Terms /Concepts :

21. LAWS OF SPECTROMETRY:
•Lambert’s Law and
•Beer’s Law Or Beer’s-Lambert’s
Law

26. Single Beam Spectrophotometer
Cells or Cuvettes
Filters

27. Single Beam Spectrophotometer :

30. Applications:
•Single beam spectrophotometer is used to measure absorbance or
transmittance of the materials.
•Single beam spectrophotometer is used to find out concentration
of unknown solutions as follows,
Determination of unknown conc. by calculation:

31. 2) Determination of unknown conc. by Graph :
If absorbance of various standard or known solutions are
measured at different concentrations and the values of
concentration of standard solution (C1) are known, then
concentration of unknown solution (C2) can be determined as
shown in the graph.

32. Chromatography
Gas-Liquid
Chromatography(GLC)

33. Chromatography is a physical
method of separation where the
components of the mixture are
separated over support due to
differential movement caused by
continuous distribution between a
stationary and mobile phase.
(Remark: Stationary phase may be solid or
liquid whereas mobile phase may be liquid
or gas)

34. What is Chromatography?
Chromatography is a technique for
separating mixtures into their components
in order to analyze, identify, purify, and/or
quantify the mixture or components.
Separate
• Analyze
• Identify
• Purify
• Quantify
Components
Mixture

35. Illustration of Chromatography
Components
Affinity to Stationary
Phase
Affinity to Mobile
Phase
Blue ---------------- Insoluble in Mobile Phase
Black        
Red       
Yellow          
Mixture Components
Separation
Stationary Phase
Mobile Phase

37. Classification of Chromatography
On the basis of Stationary Phase

38. Gas Liquid Chromatography
Here the mobile phase is an unreactive gas ( eg Nitrogen)
flowing through a tube.
And the stationary phase is an involatile liquid held on
particles of a solid support.

39. In the animation below the red molecules are more soluble in the liquid
(or less volatile) than are the green molecules.

40. Oven
Detector
Injection
port
Nitrogen
cylinder
Column
Recorder

42. Gas Liquid Chromatography (GLC):

43. GLC is Gas Liquid Chromatography technique
which is used for separation of mixture into its
individual pure components by moving gaseous
mobile phase passing over a liquid
stationary phase.
Principle: In GLC, the mixture to be
separated is vaporized and passed through the
column along with inert gas. The column is
packed with a solid porous material and low
volatile liquid is get adsorbed on it. Here, inert
gas acts as a mobile phase whereas the volatile
liquid acts as a stationary phase. The
components of mixture separate according to their
increasing order of partition coefficients /
distribution coefficients.

45. Advantages of GLC:
1) It gives satisfactory separation of even complex
mixtures.
2)Small quantities of sample (in micro scale)
can be analyzed with the help of GLC.
3)Mostly, sample cannot be wasted.
4)The results obtained are more accurate and
reliable.
5)Results are obtained within short time period.
6) Any compound that can be volatilized can be
separated.
7) Most of GLC are now compatible with printer
and other devices. So, data can be stored, printed
and managed easily. e.g. GCMS

46. Applications: GLC is used
•For separation of mixture into its pure components
individually.
•For the qualitative and quantitative analysis of components
in a mixture.
•To find out the presence of impurities in a substance.
•For analyzing fuel gases.
•For analyzing Auto exhaust gases.
•For identification of natural products.
•For the product quality control,
•For biomedical applications.
•For analysis of commercial products and in forensic
chemistry.
•For the study of atmospheric pollutants.
• For the study of reaction mechanism.
•To separate amines.
•In petroleum industry for the analysis of crude petroleum
products, gasoline, waxes etc.
•In food industry, it is used to account for the colour and
flavor of food.

47. Home Assignments:
Q.1) What are the advantages and disadvantages of instrumental
methods of chemical analysis? 4M
Q.2) Draw neat labeled diagram of glass electrode and explain its
principle, construction and working. 4M
Q.3) Write short note on ‘Applications of pH-metry’. 4M
Q.4) Write short note on 4M
a) Lamberts law Or State Lamberts law & derive expression for it.
b) Beer-Lamberts law Or State Beer-Lamberts law & derive
expression for it.
Q.5) With schematic diagram, explain principle, construction and
working of single beam spectrophotometer. 4M
Or Explain working of single beam spectrophotometer with suitable
diagram. How it can be used to determine the concentration of
unknown solution?
Q.6) With schematic diagram, explain principle, construction and
working of gas-liquid chromatography (GLC). 4M
Q.7) What is Chromatography? How are they classified on the basis
of mobile and stationary phase? 4M
Or Give the classification of chromatography. 4M
Q.8) What are the applications of GLC? 4M