The Difference Between Filter Paper and Chromatography
Filtration is a purely physical separation: liquid particles can pass through the pores, while larger solid particles cannot.
Chromatography, however, involves interactions at the molecular level, with unstable or even permanent bonds between solutes, solvents, and stationary phases.
Why is filter paper used in chromatography
Filter paper for laboratory use is a relatively important supply, so, we want to be skilled in the use of filter paper, which is a necessary procedure in each of our chemical experiments. Filter paper most filter paper is made of cotton fiber, so we have to use different methods for different purposes. Moreover, because it is made of fiber, it has innumerable holes in its surface through which liquid particles can pass, whereas larger solid particles cannot.
This property permits the separation of mixed liquid and solid substances. What’s more, filter paper is a kind of filter tool commonly used in chemical laboratories. It is usually filter paper disc and made of cotton fiber. In addition, chromatography filter paper is based on filter paper as an inert support. Because the cotton fiber in filter paper has a good affinity for water, 20 micron filter paper can absorb about 22% of the water, and 6~7% of the water in the form of hydrogen bond and cellulose hydroxyl, in general conditions more difficult to remove. Compared with the affinity with water, the cotton fiber in filter paper has a weaker affinity with organic solvents.
The function of filter paper chromatography
Therefore, in most cases, filter paper for chromatography takes the combined water in filter paper fiber as the fixed phase, while the mobile phase is dominated by organic solvents.
When the mobile phase of the organic solvent passes through the sample, the water, and the organic phase will be continuously distributed, and then with the mobile phase constantly moving, the material of various components will be continuously redistributed, further separating and purifying the material. This use of filter paper is common in chemical laboratories. Both water and alcohol can be filtered.
Chromatography paper vs filter paper
Filter paper chromatography and filter paper are two completely different concepts. Filter paper is actually a sieve, but its hole is relatively small, on the packaging box of filter paper has instructions, the size of the aperture. Generally use a medium-hole filter paper.
Filter paper does not reach the molecular level unless the molecules are very large, such as high molecular weight polymers. So filtering is generally to remove mechanical impurities.
Chromatography is actually a method to diffuse different substances in the solution in the separation, generally speaking, because different substances on the filter paper diffusion rate are not the same, with the passage of time, to different parts of the filter paper.
Using filter paper for chromatography is also called chromatography filter paper. If you know anything about the experiment of separating chlorophyll in biology class, you can use paper chromatography filter paper.
To know more about filter paper, please click The Difference Between Qualitative and Quantitative Filter Paper and Folding Method And Operation Steps Of Filter Paper.