Because the cotton fiber in the filter paper has a good affinity with water, it can absorb about 22 percent of the water, in the form of a hydrogen bond with cellulose water has 6 to 7 percent. In general, it is very difficult to remove. Compared with the affinity with water, the affinity between the cotton fiber in filter paper and the organic solvent is weaker.
Therefore, in most cases, the paper chromatography method takes the bound water in the filter paper fiber as the fixed phase, while the mobile phase is dominated by the organic solvent. When the mobile phase of the organic solvent passes through the sample, the water, and the organic phase are continuously distributed. Then, as the mobile phase keeps moving, the substances of various components are continuously redistributed, further separating and purifying the substances. This use of filter paper is commonly found in chemical laboratories.
How to use filter paper
In the experiment, the filter paper is often used together with filter funnel and brinell funnel. Fold the filter paper into a suitable shape before use. The higher the folding degree of the filter paper, the higher the surface area it can provide and the better the filtering effect. Place the glass rod of drainage on the multi-layer filter paper, force evenly to avoid the damage of the filter paper.
In the experiment, the filter paper is often used together with filter funnel and brinell funnel. Fold the filter paper into a suitable shape before use. The higher the folding degree of the filter paper, the higher the surface area it can provide and the better the filtering effect. Place the glass rod of drainage on the multi-layer filter paper, force evenly to avoid the damage of the filter paper.
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