2004
WHO Guidelines For Herbal Drug Standardization
By - 09/19/2004
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Sapna Shrikumar*, M. Uma Maheswari, A. Suganthi, T.K. Ravi.
Department of Pharmaceutical Analysis, College of Pharmacy, Sri Ramakrishna Institute of Paramedical Sciences, Coimbatore-44, India.
Isolation And Purification Of Substance By Column Chromatography
By - 07/01/2004
Principle:
In column chromatography, the stationary phase is held in a narrow tube i.e. column and the mobile phase is forced through the tube under pressure or by gravity. Generally silica gel is used as stationary phase which is polar in nature. Substances with higher polarity adsorb more strongly to polar support of silica gel and are eluted more slowly than less polar substances. Thus the least polar substance usually elutes i.e. comes out first from the column and highly polar substance usually elutes last from the column. Solvent can be removed from the eluent by evaporation to isolate the substance in relatively pure form.
Procedure:
