Though a bit of a mouthful, chromatography is simply a scientific process used to separate the various components of a mixture. There are several variations in chromatography techniques, meaning that the needed chromatography supplies will be influenced by the specific kind of chromatography practice used.
There are four key overarching categories of chromatography:
- Paper chromatography
- Gas chromatography
- Thin-layer chromatography
- Liquid chromatography
But what is chromatography? Let’s take it back to the basics first.
What is Chromatography?
Since chromatography aims to separate mixtures, it’s no surprise that the technique is used in many industries and lines of work.
Chromatography can be applied to determine what a liquid is comprised of, identify unknown substances, for purification, analysis purposes, and more.
What is Chromatography HPLC?
Chromatography HPLC, or high-performance liquid chromatography, is a widely used liquid chromatography technique applied to separate the components of a chemical mixture.
How does Chromatography work?
So, how does chromatography actually work?
Even though there are numerous different variations of chromatography techniques, the same overarching concept and factors remain present:
- The mixture
- The mobile phase
- The stationary phase
- The retention factor
The Mobile Phase
The mobile phase is just that: mobile. The mobile phase is typically a liquid or a gas, and it’s used to move the mixture in a column through the stationary phase.
The Stationary Phase
The stationary phase is (you guessed it) stationary. Accordingly, the stationary phase is a column-contained solid but permeable substance for the mobile phase to pass through.
The Retention Factor
As the mobile phase moves through the stationary phase, individual components of the mixture will separate and linger in the stationary phase for more extended periods than others. This is because the mixture’s components interact and react differently to the stationary and mobile phases.
The retention factor is a quantitative measurement representing a ratio of the time a component lingers in the stationary phase compared to the time it remains in the mobile phase.
What Chromatography Supplies Do You Need?
Various factors will influence the specific chromatography supplies needed to execute the separation process effectively. However, four tools are utilized in more commonly used techniques, such as high-performance liquid chromatography (HPLC). These tools are:
- A pump to transfer the mobile phase through the column
- An autosampler to insert the mixture
- A stationary phase and column to separate the mixture’s components
- A detector to measure the compounds
In order to get accurate results, the chromatography supplies must be appropriate for the setting and purpose of the applied chromatography technique. For instance, the chromatography caps and chromatography septa utilized can have an immense impact on the success of the chromatography process.
Chromatography caps are simply the lids used to close vials of the mixture.
Chromatography septa are the material that lines the inside of the chromatography cap to help provide a more robust seal. For example, chromatography septa are often made of rubber.
Don’t fret! We weren’t pulling your leg when we said there are many different chromatography approaches. We’ve compiled a list of some of the other chromatography techniques used. These include…
- Bonded-phase chromatography
- Column chromatography
- Displacement chromatography