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The TLC plate can either be dipped in or sprayed with a stain and sometimes heated depending on the stain used. Many stains exist for a large range of chemical moieties but some examples include: [7] [16] [17] Potassium permanganate (no heating, for oxidisable groups) Ninhydrin (heating, amines and amino-acids) Acidic vanillin (heating, general ...
Chiral thin-layer chromatography is a variant of liquid chromatography that is employed for the separation of enantiomers. It is necessary to use either It is necessary to use either a chiral stationary phase or
Thin-layer chromatography is used to separate components of a plant extract, illustrating the experiment with plant pigments which gave chromatography its name. In chemical analysis, chromatography is a laboratory technique for the separation of a mixture into its components.
Thin layer chromatography (TLC) is a quick alternative to more complex chromatography methods. TLC can be used to analyze inks and dyes by extracting the individual components. [18] This can be used to investigate notes or fibers left at the scene since each company's product is slightly different and those differences can be seen with TLC.
Around 90% of all pharmaceutical separations are performed on normal phase silica gel; however, other stationary phases such as alumina can be used for samples with dissociating compounds and cellulose for ionic compounds. [4] The reverse-phase HPTLC method (similar methodology to reverse-phase TLC) is used for compounds with high polarity.
Paper chromatography is a useful technique because it is relatively quick and requires only small quantities of material. Separations in paper chromatography involve the principle of partition. In paper chromatography, substances are distributed between a stationary phase and a mobile phase.
Phosphomolybdic is used as a stain for developing thin-layer chromatography plates, [4] staining phenolics, hydrocarbon waxes, alkaloids, and steroids. Conjugated unsaturated compounds reduce PMA to molybdenum blue. The color intensifies with increasing number of double bonds in the molecule being stained. [5]
In chromatography, the retardation factor (R) is the fraction of an analyte in the mobile phase of a chromatographic system. [1] In planar chromatography in particular, the retardation factor R F is defined as the ratio of the distance traveled by the center of a spot to the distance traveled by the solvent front. [2]