The key difference between HPLC and UPLC is that the HPLC allows for the analysis of particles having their size around 5 micrometres whereas UPLC allows for much smaller particles around 2 micrometres.
HPLC and UPLC are both Liquid Chromatographic techniques that are useful in separating the components of a compound. To know the difference between HPLC and UPLC, we first need to know what HPLC is. This is because UPLC is a special version of HPLC and we can easily understand it if we know what HPLC is.
CONTENTS
1. Overview and Key Difference
2. What is HPLC
3. What is UPLC
4. Side by Side Comparison – HPLC vs UPLC in Tabular Form
5. Summary
What is HPLC?
The term HPLC stands for High Performance Liquid Chromatography. It is a technique that we can use to separate different constituents of a compound. Also, it is the most widely used technique to identify, quantify and separate components of a mixture. Besides, this technique uses a high pressure to push solvents through the column. Furthermore, the major applications of HPLC are in biochemistry for the analysis of constituents of a compound. It is an ideal way for separation and identification of amino acids, nucleic acids, proteins, hydrocarbons, pesticides, carbohydrates, antibiotics, steroids and countless other inorganic substances.
Figure 01: HPLC System in a Laboratory
In brief, the method of operation of the HPLC technique is as follows. Firstly, we should introduce the sample into the stream of mobile phase in discrete small amounts using a pump. The pump pressure should be maintained at 40 MPa. Then, this stream of mobile phase percolates through the column of HPLC. Also, the components in the sample pass through the column. However, their speeds of movement are different from each other. This difference arises due to the difference in the interactions between the sample components and the adsorbent inside the column. We call this adsorbent as the stationary phase because it resides inside the column (not moving). Secondly, at the end of the column, we can collect the sample that elutes from the column. There we can determine the differences in retention times for each component in the sample.
What is UPLC?
The term UPLC stands for Ultra High-Performance Liquid Chromatography. It is a variation of HPLC, but the method of operation is the same. However, unlike HPLC, this method allows very small particles to be analyzed, such as 2 micrometres small particles.
Figure 02: A UPLC Device
Moreover, it provides a faster analysis. In this technique, we use a 100 MPa pump pressure for the insertion of the sample into the column. Hence, this high pressure confirms that the whole sample is introduced into the column. Thus, this is very efficient compared to HPLC.
What is the Difference Between HPLC and UPLC?
The term HPLC stands for High Performance Liquid Chromatography whereas the term UPLC stands for Ultra High Performance Liquid Chromatography. Therefore, the UPLC technique is a developed version of HPLC. Thus, the method of operation is the same for both techniques. However, UPLC is more efficient compared to HPLC because it uses a high pump pressure; the pump pressure for HPLC is 40 MPA while it is 100 MPa for UPLC. Therefore, this is a difference between HPLC and UPLC. Above all, the key difference between HPLC and UPLC is that the HPLC allows for the analysis of particles having their size around 5 micrometres whereas UPLC allows for much smaller particles around 2 micrometres.
Summary – HPLC vs UPLC
UPLC is a form of HPLC. Thus, the operation methods are the same. But, we can find some improved features in UPLC compared to HPLC. Therefore, there is some difference between HPLC and UPLC. However, the key difference between HPLC and UPLC is that the HPLC allows for the analysis of particles having their size around 5 micrometres whereas the UPLC allows for much smaller particles around 2 micrometres.
Reference:
1. “High-Performance Liquid Chromatography.” Wikipedia, Wikimedia Foundation, 20 Oct. 2018. Available here
2. “UPLC.” Wikipedia, Wikimedia Foundation, 25 Oct. 2017. Available here
Image Courtesy:
1.”Hplc”By Kjaergaard at English Wikipedia (Public Domain) via Commons Wikimedia
2.”Picture of a UPLC device”By Groep29 BFW – Own work, (Public Domain) via Commons Wikimedia