What Is Chromatography?

What method can assist with testing food, beverages, forensics, and drugs; plus producing vaccines? 

Chromatography, of course. 

The word originates from Greek roots, “chroma,” meaning “color,” and “graphy,” meaning “to write.” 

Read on to learn how this technique works.

Chromatography at Its Simplest

Mikhail Tsivet receives credit for his initial experimentation with chromatography in 1900 amongst plant pigments (hence chromatography’s “colorful” name).

Chromatography separates a mixture’s constituents. Such constituents spread unevenly across 2 distinct, unmixable phases: mobile and stationary. You can typically find the mobile phase as a gas or liquid, while the stationary a solid. 

Different types of chromatography arise from each phase’s form. Gas chromatography arises from a gas mobile phase, liquid chromatography from a liquid mobile phase. 

What Is Chromatography Doing to Work?

 Return to the mobile and stationary phases. The mobile phase moves through said stationary phase, a mixture in tow. That mixture’s constituents separate, moving at different speeds along phases.

Constituents bind more or less effectively at various points throughout mobile and stationary phases. Each constituent has unique binding properties that affect this. 

Thus, you can pinpoint a mixture’s constituents based on where they “stick better” throughout phases.

Specific Types of Chromatography

2 common chromatography techniques include:

1. High-performance liquid chromatography (HPLC)
2. Gas chromatography

HPLC chromatography has a liquid mobile phase with a columnal stationary phase. This varies from normal, as the mixture under separation experiences high pressures moving past phases. As such, this technique moves much faster. 

Gas chromatography means that you vaporize and expose a specific constituent to an unreactive gas. This gas moves the constituent through phases in a column. 

These 2 techniques also come with their own equipment.

Chromatography Equipment

You can find the following common chromatography equipment:

• Columns
• Frits
• Flow cells
• Pumps
• Detectors
• Software systems for the different chromatography techniques
• Vials
• Mass spectrophotometers

Some equipment stays specific to one chromatography technique. For example, HPLC chromatography requires special chromatography vials. You can purchase these through various suppliers, such as chromtech.com.

Standard lab equipment and safety protocol apply (e.g., lab coats, goggles) in addition to the above. 

Other Common Chromatography Terms

You now know how chromatography works, what different techniques entail, and which equipment to use. However, you still have to learn a few other terms that people commonly associate with the method. Such a list may incorporate:

• Analyte
• Eluent
• Distribution ratio
• Retention time

Analyte just references a constituent within a mixture. 

Eluent becomes another word for the mobile phase.

Distribution ratio equals the amount of constituent in the stationary phase over the amount of constituent in the mobile phase.

Retention time refers to how much time it takes for a constituent to go through a chromatography column (remember the different types of chromatography!).

These terms help prevent people from confusing chromatography’s common components amongst productive conversations.

Chromatography’s Importance

Overall, chromatography proves a very important and powerful technique for multiple applications. It continues to improve while helping solve many problems in various industries.

Simply put, chromatography uses a basic idea to create comprehensive solutions. Check out related posts if you want to learn more about it!