6. What is chromotography?
Chromotography is a labortary technique for
the separation of a mixture. Chromatography
may be preparative or analytical.
The purpose of preparative chromatography
is to separate the components of a mixture
for later use, and is thus a form
of purification.
Analytical chromatography is done normally
with smaller amounts of material.
7. History
Chromatography was first employed in
Russia by the Italian-born
scientist Mikheil Tsvet in 1900.
For the separation of plant pigments such
as chlorophyll, carotenes, and
xanthophylls chromotography was first
applied.
8. types:
There are five main types of chromatography.
1. LiquidChromatography
2. Gas Chromatography
3. Silver ion Chromatography
4. Paper chrmotography.
5. Thin layer chromotography.
9. Silver Ion Chromotography
Silver ion chromatography is applied for
the analysis and separation of lipids.
The first report of silver ion
chromatography as a method for
separation of fatty acids was in 1962.
Silver-ion chromatography separates
Triglycierides according to their degree of
unsaturation.
10. Mechanism:
1. Incorporate 10-20% of silver nitrate into the
aquaoues solution of silica gel.
2. Spreading this solution to the plate.
3. Nessecary care to exposure to light.
4. Be careful with the immersion of silver nitrate
solution in methanol.
5. The activated plates should be stored in the
dessicator in the dark.
6. Lipids are spotted on to the TLC plate.
11. Mechanism:
1. Lipids developed in a closed tank (in the dark)
are mobile phase(liquid phase).
2. Chromatography is carried out at ambient
temperature.
3. Remove the plates from the tank, and dried in
a stream of air or nitrogen.
4. Components separated by silver-ion HPLC are
commonly detected by evaporative light-
scattering detectors (ELSD).
12. Refrences:
1. Morris, L. J. In New Biochemical Separations, edited
by A. T. James and L. J. Morris. D. Van Nostrand Co.,
London, 1964, p. 295. Den Boer, F. C.
2. Anal. Chem. 205: 308, 1964. Jurriens, G. Riv. Ital.
delle Sostanze Grasse no vol: 116, 1965.
3. Mangold, H. K. J. Am. Oil Chemists’ Soc. 41: 762,
1964.
4. Scholfield, C. R. In Fatty Acids, edited by K. Markley.
Interscience Publishers, New York, 1964, 2nd ed., p.
2283.
5. Radin, N. S. J. Am. Oil Chemists’ SOC. 42: 569,
1965
