This document discusses the basic principles of chromatography. Chromatography is a technique used to separate mixtures into individual components by using a stationary phase and mobile phase. The stationary phase is in a column and absorbs the mixture's components at different rates, while the mobile phase carries the mixture through the column. Components separate because they interact differently with the stationary phase based on their polarity and elute from the column at unique retention times when detected. Together, the stationary and mobile phases allow chromatography to separate mixtures into purified components.

1. Dr. M. Vairalakshmi, Assistant Professor of Chemistry, V.V .Vanniaperumal College for Women , Virudhunagar.
Basic
Principle
of
chromatography
Principle of chromatography
Dr. M. Vairalakshmi
Assistant Professor of Chemistry,
V. V. Vanniaperumal College for Women,
Virudhunagar - 626001.

2. Dr. M. Vairalakshmi, Assistant Professor of Chemistry, V.V .Vanniaperumal College for Women , Virudhunagar
Basic
Principle
of
chromatography
2
What is Chromatography?
The stationary phase is a column which adsorbs the components of the mixture
and it does not move with the sample. Example: silica gel, calcium carbonate,
activated charcoal, etc.
The mobile phase is either a liquid or gas, which is passed through a
chromatographic column where the components of the mixture are separated at
different rates by adsorbing to the stationary phase.
Chromatography is an analytical technique used for
separating a mixture of chemical substances into its
individual components and purifying that components.

3. Dr. M. Vairalakshmi, Assistant Professor of Chemistry, V.V .Vanniaperumal College for Women , Virudhunagar
Basic
Principle
of
chromatography
Principle
 Chromatography is a separation method where the analyte is combined
within a liquid or gaseous mobile phase, which is pumped through a
stationary phase.

4. Dr. M. Vairalakshmi, Assistant Professor of Chemistry, V.V .Vanniaperumal College for Women , Virudhunagar
Basic
Principle
of
chromatography
 Depending on their polarity they spend more or less time interacting with the stationary
phase and are thus retarded to a greater or lesser extent. This leads to the separation of
the different components present in the sample.
 Each sample component elutes from the stationary phase at a specific time called as
retention time.
Retention time (TR) is the time needed for each component of the mixture after injection to
reaches the detector.
Unit: seconds / minutes
TR = tM + tS
where,
tM : time taken for the mobile phase to pass through the column from injector to detector
tS: time taken by the analyte retained in the stationary phase

5. Dr. M. Vairalakshmi, Assistant Professor of Chemistry, V.V .Vanniaperumal College for Women , Virudhunagar
Basic
Principle
of
chromatography
 As the components pass through the detector their signal is recorded and plotted in
the form of a chromatogram.

6. Dr. M. Vairalakshmi, Assistant Professor of Chemistry, V.V .Vanniaperumal College for Women , Virudhunagar
Basic
Principle
of
chromatography
6
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