The main difference between preparative and analytical chromatography is that the main purpose of preparative chromatography is to isolate and purify a reasonable quantity of a specific substance from a sample whereas the main purpose of analytical chromatography is to separate the components of a sample. Furthermore, preparative chromatography is done in large scale while analytical chromatography is done in small scale.
Preparative and analytical chromatography are two types of chromatography techniques classified based on the purpose of the chromatography.
Key Area Covered
1. What is Preparative Chromatography
– Definition, Purpose, Parameters
2. What is Analytical Chromatography
– Definition, Purpose, Parameters
3. What are the Similarities Between Preparative and Analytical Chromatography
– Outline of Common Features
4. What is the Difference Between Preparative and Analytical Chromatography
– Comparison of Key Differences
Key Terms
Analytical Chromatography, Isolation of Compounds, Preparative Chromatography, Separation
What is Preparative Chromatography
Preparative chromatography is a type of chromatography used to isolate a particular substance in a sample in large scale. Therefore, the main purpose of preparative chromatography is to purify a particular substance. The main chromatographic techniques in preparative chromatography are Gas chromatography (GC), liquid chromatography (LC), and high performance liquid chromatography (HPLC). Capillary electrophoresis is another preparative chromatography method used to separate charged molecules such as proteins and nucleic acids.
Figure 1: Preparative HPLC Apparatus
The amounts of the products are either mL/L or mg/g quantity. The products obtained from the preparative chromatography can be used as a food supplement, pharmaceutical or biotherapeutic.
What is Analytical Chromatography
Analytical chromatography is the typical chromatography method used to identify the components of a mixture and their proportions. The main purpose of analytical chromatography is the qualitative and quantitative analysis of the components of a mixture. Any chromatographic techniques can be used in analytical chromatography.
Figure 2: Separation of Plant Extract with TLC
After the analysis, the whole mixture is simply diverted to waste. Generally, the parameters of the analytical chromatography are scaled up to obtain large scale products by preparative chromatography.
Similarities Between Preparative and Analytical Chromatography
- Preparative and analytical chromatography are two chromatography techniques classified based on the purpose of the chromatography.
- Analytical chromatography techniques can be scaled up to preparative chromatography in order to achieve a large scale separation.
Difference Between Preparative and Analytical Chromatography
Definition
Preparative chromatography refers to a form of separation of solutes in large scale, utilizing the partition of the solutes between stationary and mobile phases while analytical chromatography refers to a technique designed to separate out the constituent parts of a mixture by exploiting their ability to be distributed, to different extents, between a stationary phase and a mobile phase.
Purpose
The main purpose of preparative chromatography is to isolate and purify a reasonably sufficient quantity of a particular substance from a mixture while the main purpose of analytical chromatography is to determine the presence and the relative proportions of analytes in a mixture.
Large/Small Scale
Preparative chromatography is done in large scale while analytical chromatography is done in small scale.
Types of Chromatographic Techniques
HPLC, LC, and GC are the chromatographic techniques mainly involved in preparative chromatography while many chromatographic techniques are involved in the analytical chromatography such as paper chromatography, TLC, column chromatography, ion-exchange chromatography, affinity chromatography, GC, LC, HPLC, etc.
Sample Number and Volume
In preparative chromatography, both sample number and sample volume are high while in analytical chromatography, sample number and sample volume are less.
Column Diameter
The column diameter of preparative chromatography is typically 50 – 200 mm range in LC while the column diameter of analytical chromatography is 4.6 to 2.1 mm range in LC.
Length of the Column
Long columns are better for preparative chromatography while short columns are sufficient for analytical chromatography.
System Backpressure in LC
The backpressure of preparative LC is 10 bar while the backpressure of typical analytical HPLC is 100 -1500 bar.
Downstream Processing
The products obtained from preparative chromatography are used in the downstream processing while the products of the analytical chromatography may not even be collected.
Conclusion
Preparative chromatography is a large scale chromatographic method used to purify a specific component from a mixture while analytical chromatography is a small scale chromatographic method used for the qualitative and quantitative analysis of the components of a mixture. Therefore, the main difference between preparative and analytical chromatography is the purpose and the amount of products.
Reference:
1. “Preparative Chromatography – Introduction.” Chromatography Online, Available Here
2. Coskun, Ozlem. “Separation Techniques: Chromatography.” Northern Clinics of Istanbul 3.2 (2016): 156–160. PMC. Web. 17 July 2018. Available Here
Image Courtesy:
1. “Preparative HPLC” By GYassineMrabetTalk This vector image was created with Inkscape. – Own work (CC BY 3.0) via Commons Wikimedia
2. “Chromatography of chlorophyll – Step 7” By Flo~commonswiki – Own work (CC BY-SA 2.5) via Commons Wikimedia
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