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The chromatography is a method of separation of mixtures complexes widely used throughout different branches of the science. Employs a set of techniques based on the principle of selective retention to separate the components of a mixture in a high state of purity, or to identify them in a mixture and determine their exact proportion.
In that way, the chromatography consists of exposing a certain mixture to a specific support (gas, paper, a liquid neutral, etc.) in order to take advantage of the differences in the adsorption speed of each component of the mixture, identifying them from the color spectrum that the mixture produces over time.
Adsorption (no absorption) is the coefficient of adhesion of the mixture to the surface of the support, and according to the difference in reaction rates of the components of the mixture, these may be effectively separated or their concentration percentage may be measured in any case.
This separation process occurs in two phases:
- Static phase. The mixture is applied to a specific support and prepared for measurement.
- Mobile phase. Another substance is moved on the support, to allow its reaction with the components of the mixture and that the difference in the reaction rate separates them.
In this way, some substances they will tend to move and others to stay, according to their respective natures. This can be carried out using aesthetic and mobile phases of various conditions: liquid, solid and gaseous.
See also: Examples of Mixtures
Chromatography examples
- Spilling wine on a white tablecloth. As the wine dries in contact with air, the various substances that compose it will dye the white of the fabric a different color, thus allowing them to be identified when it would normally be impossible.
- In blood tests. Chromatography of blood samples is often performed in order to separate and identify substances contained in it, normally imperceptible, from the color they reflect on a support or subjected to a specific light. Such is the case of a drug or a specific substance, such as alcohol.
- In a urine test. Urine, even more than blood, is a mixture of various compounds, the presence or absence of which reveals how the body works. Hence, a chromatographic separation can be performed to look for unusual residuessuch as blood, salts, glucose, or drugs.
- Crime scene review. As in the movies: fabrics, fibers, fabrics or other supports are taken to observe the adhesion separation of different substances, such as semen or blood, which at first glance could go unnoticed.
- Food health checks. Since the reaction of foods when subjected to a chromatographic spectrum is known, It can be seen if there is some type of improper substance or product of microbial agents in them from a small sample.
- Verification of contamination levels. Whether in air or water, the reaction of dissolved and imperceptible substances can be measured from a small sample, using a specific support that allows distinguishing between the compounds, letting the water dry, for example.
- Complex microbiology tests. This technique is widely used to combat diseases such as Ebola, for example, because in this case allows the distinction between the most and least effective antibodies in the face of deadly disease.
- Petrochemical applications. Chromatography is useful in the process of separating hydrocarbons of oil and its transformation into various refined materials, which have highly dissimilar and observable properties and adhesions.
- Fire check. To determine whether or not they were provoked, residue chromatography is often used to determine show the presence of unexpected substances whose reactivity is different from the rest, as certain fossil fuels.
- To separate inks. Since inks are composed of various pigments in a liquid medium, it is possible to separate these pigments by chromatography and highlight the differences between each one. It is, in fact, a common experiment when it comes to explaining this technique, using colored markers.
- Radioactivity detection. Since radioactive elements have different activities and emission rates than ordinary matter, they can often be identified using this technique in the laboratory. exposing matter to substances that show the change in reaction rate.
- To determine the purity of a substance. High purity materials are often required in industry, especially gases (the volatility of which makes this difficult) and a mechanism to assess this is the chromatographic detection of residues of other substances, from the use of a liquid static phase.
- Study of wines. In the detection of monovarietal wines, chromatography is often used to know if they are mixed with other strains, since these will present different characteristics detectable in the presence of a different static medium.
- Control of the industrial distillation of spirits. By gas chromatography, the basic quality components present in the liquor can be identified and quantified (ethanol, methanol, acetaldehyde, acetal, etc.), thus allowing responsible administration of said compounds.
- Quality studies of olive oils. Chromatography is essential in the review and classification of olive oil, since it provides a study of the fat profile, acidity and peroxide value present in the mixture.
Other techniques for separating mixtures
- Examples of Crystallization
- Examples of Distillation
- Examples of Centrifugation
- Examples of Decantation
- Examples of magnetization
