Paper chromatography
Chromatography jar
Classification	Chromatography
Other Techniques
Related	Thin layer chromatography
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Paper chromatography is an analytical technique for separating and identifying mixtures that are or can be colored, especially pigments. This can also be used in secondary or primary schools in ink experiments they also do food colouring experiments and smarties experiments. This method has been largely replaced by thin layer chromatography, however it is still a powerful teaching tool. Two-way paper chromatography, also called two-dimensional chromatography, involves using two solvents and rotating the paper 90° in between. This is useful for separating complex mixtures of similar compounds, for example, amino acids Diagram of TLC tank drawn by Theresa Knott. ... For the Second Person album, see Chromatography (album). ... Thin Layer Chromatography (TLC) is a chromatography technique used to separate chemical compounds [1]. It involves a stationary phase consisting of a thin layer of adsorbent material, usually silica gel, aluminium oxide, or cellulose immobilised onto a flat, inert carrier sheet. ... This article does not cite any references or sources. ... Natural Ultramarine pigment in powdered form. ... Thin Layer Chromatography (TLC) is a chromatography technique used to separate chemical compounds [1]. It involves a stationary phase consisting of a thin layer of adsorbent material, usually silica gel, aluminium oxide, or cellulose immobilised onto a flat, inert carrier sheet. ... In chemistry, an amino acid is any molecule that contains both amino and carboxylic acid functional groups. ...

Technique

A small concentrated spot of solution that contains the sample is applied to a strip of chromatography paper about 2 cm away from the base of the plate, usually using a capillary tube for maximum precision. This sample is absorbed onto the paper and may form interactions with it. Any substance that reacts or bonds with the paper cannot be measured using this technique. The paper is then dipped in to a suitable solvent, such as ethanol or water, taking care that the spot is above the surface of the solvent, and placed in a sealed container. The solvent moves up the paper by capillary action, which occurs as a result of the attraction of the solvent molecules to the paper,also this can be explained as differential absorption of the solute components into the solvent. As the solvent rises through the paper it meets and dissolves the sample mixture, which will then travel up the paper with the solvent solute sample. Different compounds in the sample mixture travel at different rates due to differences in solubility in the solvent, and due to differences in their attraction to the fibers in the paper. Paper chromatography takes anywhere from several minutes to several hours.^[1] Look up absorption in Wiktionary, the free dictionary. ...

In some cases, paper chromatography does not separate pigments completely; this occurs when two substances appear to have the same values in a particular solvent. In these cases, two-way chromatography is used to separate the multiple-pigment spots. The chromatogram is turned by ninety degrees, and placed in a different solvent in the same way as before; some spots separate in the presence of more than one pigment. As before, the value is calculated, and the two pigments are identified. Paper chromatography was invented by two British biochemists, Archer John Porter Martin and Richard Laurence Millington Synge. ^[2] Archer John Porter Martin was a British chemist and Nobel Prize winner. ... Richard Laurence Millington Synge (born Liverpool, October 28, 1914, died Norwich, August 18, 1994) was a British biochemist, and winner of the 1952 Nobel Prize in Chemistry for the invention of partition chromatography. ...

This article does not cite any references or sources. (February 2008) Please help improve this article by adding citations to reliable sources. Unverifiable material may be challenged and removed.

Analysis

After development, the spots corresponding to different compounds may be located by their color, ultraviolet light, ninhydrin (Triketohydrindane hydrate) or by treatment with iodine vapors. The paper remaining after the experiment is known as the Chromatogram.The components which have been separated differ in their retention factor i.e Ratio of distance traveled from the spot or origin by the solute component to that of the distance traveled from the spot or origin by the solvent. Retention Factor can never be greater than one. To calculate R_f, use the following: Distance traveled by sample/ distance traveled by solvent. For other uses, see Ultraviolet (disambiguation). ... This article or section does not cite its references or sources. ... For other uses, see Iodine (disambiguation). ... Pictured is a sophisticated gas chromatography system. ... Retention factor, or Rf, is a concept in chromatography and is calculated as the simple ratio: In most cases, the paper used to measure retention factor is polar, (due to the nature of cellulose in paper), allowing one to deduce the relative polarity of a substance being moved by the... Spot can refer to: Look up spot in Wiktionary, the free dictionary. ... Look up origin in Wiktionary, the free dictionary. ... Spot can refer to: Look up spot in Wiktionary, the free dictionary. ... Look up origin in Wiktionary, the free dictionary. ... Retention factor, or Rf, is a concept in chromatography and is calculated as the simple ratio: In most cases, the paper used to measure retention factor is polar, (due to the nature of cellulose in paper), allowing one to deduce the relative polarity of a substance being moved by the...

The final chromatogram can be compared with other known mixture chromatograms to identify sample mixes using the R_f value in an experiment. The retention values found can be compared to known values, and from that conclusions can be drawn. Retention factor, or Rf, is a concept in chromatography and is calculated as the simple ratio: In most cases, the paper used to measure retention factor is polar, (due to the nature of cellulose in paper), allowing one to deduce the relative polarity of a substance being moved by the...

References

1. ^ Das, D (2005). Biochemistry. Academic Publishers, pp.187-188
2. ^ Chromatography - The first chromatograph, Ion-exchange chromatography, Paper chromatography, Martin and synge

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