Paper chromatography

Experiment or Lab Report

1. Email: [email protected]
Lab Report No: 01
Paper Chromatography
Applied Chemistry ІІ (Lab)














Submitted by: Muhammad Zakaria
Registration No: 16PWCHE1111
Submitted to: Dr. Najeeb Ullah









Date of Submission: 21, February, 2017
DEPARTMENT OF CHEMICAL ENGINEERING
UNIVERSITY OF ENGINEERING TECHNOLOGY, PESHAWAR

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CHROMATOGRAPHY:

Chromatography is analytical technique of separation or identifying of
components of a mixture. The basic principle of chromatography is that
different components of a mixture have different tendencies of absorption
onto a surface.
There are two parts that is necessary for chromatography i.e.
 Stationary Phase
 Liquid Phase
Basis of these two parts there are several types of chromatography i.e.
 Paper Chromatography
 Gas Chromatography
 Absorption Chromatography
 Partition Chromatography
GAS CHROMATOGRAPHY:
In this type of chromatography gas is used as mobile phase and stationary
phase can be solid or liquid. If solid is used as stationary phase then it is called
Gas solid absorption chromatography, and if liquid is used then it is called Gas
liquid partition chromatography. In both cases the stationary phase are taken
in a narrow column and the particles of stationary phase ar coated onto inside
of column.
ABSORPTION CHROMATOGRAPHY:
In Absorption chromatography there is a solid stationary phase and liquid or
gaseous mobile phase. Each part of mixture has its own absorption power to

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the stationary phase. The best absorbed one travel slowly and vice versa. The
result is separation of mixture into different bands while each band represent
different part of solution.
PARTITION CHROMATPGRAPHY:
In partition chromatography the stationary phase is a non-volatile liquid which
is held as a thin layer on the surface of an inert solid. The mixture to be
separated is carried by a gas or a liquid as the mobile phase. The solutes
distribute themselves between the moving and the stationary phases, with the
more soluble component in the mobile phase reaching the end of the
chromatography column first.
PAPER CHROMATOGRAPHY:
Paper chromatography is a method of separating mixtures by using a piece of
absorbent paper and a solvent. In this process, the mixture to be separated is
placed on a piece of paper. The paper is the stationary phase. The solvent, or
mobile phase, is allowed to travel across the paper. As the solvent front moves,
the components of the mixture separate. Due to the difference in relative
attraction which each component in the mixture has to the paper and to the
solvent, the parts of the mixture separate as each travels a different distance
up the paper. The components of the mixture which are most attracted to the
solvent travel farthest with the solvent. The components of the mixture which
are most attracted to the paper move slower, remaining closer to where they
were originally placed, the origin. The different polarities of the paper, solvent
and mixture components determine the degree of attraction between each.

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EXPERIMENT:
TO IDENTIFY DIFFERENT COMPONENTS OF A MIXTURE USING
METHOD OF PAPER CHROMATOGRAPHY.

APPARATUS:
 Pencil.
 Paper strips.
 Beaker.
CHEMICALS:
 Ethanol.
 Water
 Inks (blue & red).
PROCEDURE:
 Cut the chromatography paper in about 4 x 10cm strips.
 Draw a horizontal line with pencil about 2cm from the lower edge of the
strip.
 This will be your base line, the starting line where the samples will be
spotted.
 Now draw three lines vertically on strip with help of pencil.
 Apply three dots of ink on the baseline that is one from blue ink, one
from black ink and one from mixture of these two inks.
 Make sure dots are evenly spaced on the baseline and not too close to
the edge.
 It may be helpful to use a pencil to mark the spots before placing the ink
on the paper, see the diagram below.
 Stand the paper in solution (60% ethanol 40% water solution).

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 Taping the top of the strips to the side of the beaker may be helpful.
 After twenty minutes remove the paper strip from the solution.
 Calculate Retardation Factor for each separated component of the
mixture.

DIAGRAM:




Solvent front.



Solute front



Retardation factor = Solute font / Solvent front
CALCULATIONS:
Solvent front= 6cm
Rf for red color: Solute front= 4cm
So Rf =
4????????????
6????????????
⁄
Rf = 0.666

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Rf for blue color: Solute front= 1.5cm
So Rf =
1.5????????????
6????????????
⁄
Rf = 0.25
PRECAUTIONS:
 Pencil must be used for marking the strip.
 Reading of solute front must be taken from the middle as shown in the
diagram.
 The beaker must be washed.
LIMITATIONS OF PAPER CHROMATOGRAPHY:
 Paper chromatography can be used only for colored compounds only.
 For colorless compounds locating agent must be used.
APPLICATIONS OF PAPER CHROMATOGRAPHR:
 Paper chromatography is used in the sequencing of DNA and RNA.
 It is used in scientific studies to identify unknown organic and inorganic
compounds in a mixture.
 To detect the containments in food and drinks.
 To study the ripening and fermentation.
 It is used for the detection of drags and dopes in animals and humans.




THE END.