it means that the solute has no affinity for the stationary phase and
has moved the entire distance along with the solvent front.
Rf is 1
Factors affecting Rf Values:
a. Temperature
b. Solvent used
c. Quality of the Paper
d. Techniques employed
e. Distance travelled by the solvent and the solute
f. Chemical Reactions between the substance to be separated and the solution
g. The concentration of the separated substance.
Main basic Principle: of paper chromatography
Partition
Paper chromatography is a form of liquid chromatography where the basic principle involved can be
either
partition chromatography or adsorption chromatography.
is between solid and liquid phases, where the solid surface
of the paper acts as a stationary phase. and the liquid phase is the mobile phase. Solute is
absorbed on the surface of ST.
Paper Adsorption Chromatography
ST. The more strongly. it is absorbed. the () it travels
through the column.
slower
It is a liquid-liquid chromatography. The cellulose layer in filter paper contains moisture,
which acts as a stationary phase. Organic solvents or buffers are used as the mobile phase.
Paper Partition Chromatography
Paper Partition Chromatography The principle of separation is mainly () rather than adsorption.
partition
Substances are
distributed between a stationary phase and a mobile phase. cellulose layers in filter paper
contain moisture which acts as a
stationary phase
INSTRUMENTATION:
1. Stationary phase:
Whatman filter papers:
Modified papers:
Hydrophilic Papers
Hydrophobic papers
Impregnated papers:
Whatman filter papers: Grades
No. 1, No.2, No.3, No.4, No.20, No. 40, No.42
In general, the paper has () a-cellulose,() of b-cellulose.
99-99%, 0.3 - 1%
These sheets contain varying pore diameters and thickness, providing for greater () in separating various
chemicals.
adaptability
treated to eliminate
contaminants that may interfere with the analysis.
Acid or based washed filter papers
Modified papers: For example,
Acid or base washed filter paper
Modified papers: are also utilized because
they have better chemical resistance and stability.
Glass fiber sheets
Papers modified by methanol, formamide glycol, glycerol and other
hydrophilic compounds.
c. Hydrophilic Papers -
These treatments increase the paper’s affinity for the (),
allowing for improved analyte separation and migration.
mobile phase
Acetylation of OH groups results in () characteristics,
which is suitable for reverse-phase chromatography.
hydrophobic
Acetylation of OH groups results in hydrophobic characteristics,
which is suitable for reverse-phase chromatography.
Hydrophobic papers