Chromatography is an analytical technique in chemistry that’s used to separate the constituent components of a mixture, either for analytical or industrial purposes.
The method was originally developed in 1903 by the botanist Mikhail Tswett, who used the technique to separate plant pigments. Although there are now several different types of chromatography, the basic principles remain the same.
The process of chromatography involves two phases – the ‘mobile phase’ and the ‘stationary phase’. A mixture is dissolved in the mobile phase (this can be a liquid or a gas), which then moves along the stationary phase. The stationary phase is a system such as a stainless steel column on which the components are fixed. The differences in the affinities and masses of a mixture during these two phases cause the constituent components to separate. Once separated, the components can then be examined more closely.
Read on to find out more about how chromatography is used in both chemistry and everyday life, and why it’s important.
In this post:
What is chromatography used for?
Chromatography is used as an analytical tool and an industrial method. As an analytical tool, it enables scientists to identify unknown samples of substances based on their relative masses and affinities.
A popular and versatile technique, it has applications in forensic science, molecular biology, food processing, chemical manufacturing, pharmaceutical testing, and environmental science.
- Forensic science – gas chromatography can be used to analyse trace evidence such as blood, hair, fabric, and skin samples at a crime scene. It can also help to identify toxins in the victim’s body during a postmortem. The events that transpired before and after the crime can then be reasonably deduced based on the analysis of trace evidence.
- Molecular biology – chromatography is a key technique used by biochemists, geneticists, and molecular biologists. Other analytical laboratory techniques, such as electrochemistry and mass spectrometry, are combined with chromatography to study complex molecules like proteins and nucleic acids. This can help scientists to understand metabolic processes and identify genetic markers.
- Food and beverage industry – chromatography is used extensively in the food and beverage industry to maintain quality control. The technique enables manufacturers to separate and analyse various nutritional compounds such as amino acids, vitamins, minerals, and food additives. It also helps them determine expiration dates and ensure ingredients remain consistent. In 2013, chromatography was used to identify types of meat during the horse meat scandal that affected some parts of Europe.
- Chemical industry – identifying harmful substances produced by the chemical industry, whether as intermediate or final products, is crucial for human safety and the environment. Some of the most common harmful chemicals are perfluoroalkyl substances (PFAS), which are found in a range of products including shoes and electronics. Chromatography can be used to identify and analyse various items for possible toxic contents.
- Pharmaceutical testing – from diagnostic or clinical laboratory analysis to regulatory testing for illicit substances, chromatography is essential to the pharmaceutical industry. It’s commonly used to test the efficacy and toxicity of medicines. It’s also used to determine the levels of illicit drugs like cocaine in urine or blood samples.
- Environmental science – various field and laboratory analytical methods, including chromatography, are used to monitor and test for pollution through water and air quality analysis. Unknown pollutants and their environmental impact can be analysed using chromatography techniques.
Why is chromatography important?
Chromatography is important for both scientific analytical purposes and industrial applications. As an analytical tool, chromatography can resolve many scientific problems such as protein synthesis. The technique is also important because it can help solve crimes through forensic analysis and ensure pharmaceutical products are effective and safe.
As an industrial tool, chromatography plays an important role in synthesising many useful chemicals, including medicines. The method also ensures petroleum products can be processed with the utmost precision. Another reason chromatography is important is because it enables new materials to be created, such as synthesising spider silk.
Is chromatography effective?
Chromatography is very effective in separating compounds in a mixture based on their relative masses and affinities. As we’ve already explained, this makes it a very useful analytical and industrial tool.
However, like many scientific techniques, chromatography does have its limitations. For example, it’s less effective at separating highly miscible substances that have very similar chemical and physical properties. In some cases, it also needs to be combined with other techniques like spectrometry to be successful.
How is chromatography used in everyday life?
From medicines and vaccines to the food we eat, chromatography plays a vital role in everyday life. It’s no exaggeration to say the technique is used in millions of clinical laboratory analyses all over the world every day.
Chromatography is very effective as a diagnostic tool and is commonly used in the pharmaceutical industry to determine which antibodies fight certain diseases and viruses. This information can then be used to develop effective vaccines, such as in the case of the coronavirus pandemic.
Another important application of chromatography in everyday life is in food testing. For example, the combination of high-performance liquid chromatography and mass spectrometry is very effective in determining the meat content of processed meat products. Meat inspectors enforce the law with the help of chromatography. 
Summary
Chromatography has a wide range of uses in chemistry, both for analytical and synthetic purposes. By determining the chemical composition of a mixture, experts can monitor the quality of various food and drink products. Chromatography is also very useful as a clinical diagnostic tool, enabling scientists to understand biological processes, identify antibodies and test drugs.
