Each sample should be dissolved in an appropriate solvent to make about a one percent solution (0.01 g sample/1 g solvent). Less than one milliliter of solution will be needed for the experiment. Then the dissolved samples may be spotted to the paper.
Touch the tip of a clean drawn-out capillary tube to the sample and let about 3 mm of the sample rise into the tube. If too much solution is drawn into the capillary, touch the tip to a piece of clean filter paper. To spot the sample, touch the capillary to the line on the chromatogram. Make sure the spot does not exceed 1 cm in diameter. Allow the solvent to evaporate.
More than one sample can be loaded onto a single piece of chromatography paper. However, all spots on the chromatogram should be 2 to 2.5 cm away from the edges of the paper and from each other.
If a larger quantity of sample is needed for the experiment than is provided by one application, the solution may be re-spotted. When the original spot has dried, draw solution into the capillary as before. Apply this solution over the top of the first spot, but do not allow the diameter of the circle to grow larger than that of the original spot. Repeat if necessary, allowing each spot to dry before the next application.
