AND THIN LAYER CHROMATOGRAPHY PAPER CHROMATOGRAPHY AND THIN LAYER CHROMATOGRAPHY

PAPER CHROMATOGRAPHI : The simplest, cheapest and most easy chromatographi. Usage : Qualitative identification Quantitative analysis Stationary phase : water absorbed by paper cellulose Mobile phase: polar organic solvent

Development Process Mobile phase creeps the paper because of capillary effect 2 techniques of creeping : a. Ascending (creep up) b. Descending (creep down)

3 steps of paper chromatography 1.Sample Spotting 2. Development 3. Identification

Spotting step Prepare chromatography paper in certain size. Make a starting line by a pencil about 2-3 cm from the edge Using a micropipette or capillar pipe spot the sample solution at the starting line. Dry it in the air.

Development step Hold the paper with a clip. Hang the paper in development container with the eluant. The edge of starting line should be dipped in the eluant. Let the eluant creeps on the paper through the sample spot. Separation result shown as colored spots on the paper. Distance of every spot to starting line are different. Eluant creeping stopped when the eluant almost reach the top edge of the paper. Take out the paper and mark the eluant end line.

Identification step Colored spot could be checked directly and the Rf could be determined. Colorless spot should be identify by : - spray the paper with identification agent. (Usualy colored complex former) - Check the paper under UV ray - Eexpose the paper to iodium vapor

THIN LAYER CHROMATOGRAPHY (TLC) TLC conducted on thin layer of silica or alumina on a plat of glass or metal Stationary phase : Silica gel or alumina. Mobile phase Pure eluant or mixed eluant.