Chromatography has a long and interesting history. To discuss such a vast subject is a challenge, people are understandably passionate about such a subject. There is huge potential of not charting or discussing an area another person believes to be critical, for example we are discussing here Liquid Chromatography, we didn’t feel there would be room or time to discuss Gas Chromatography (GC) in an appropriate amount of detail.
So before we begin, please do let us know if you have any additions or corrections, we are always open to learning more from experts within any industry as that helps us to grow and learn.
Since the mid-19th century multiple types of chromatography have been developed. To start at the beginning, the word ‘Chromatography’ stands for ‘color writing’ and was initially used for the separation of plant pigments such as chlorophyll (which is green) and carotenoids (orange and yellow). However, it soon became apparent that it could be used for a wide range of separation processes as new forms of chromatography were developed starting in the 1940s.
In the modern analytical solutions discussed here, from HPLC to GC and SCFC we have an instrument that is currently in use, allowing the finished Analytical Instruments to achieve their full potential. We have provided solutions for liquid and gas applications, using thermal mass flow technology allowing manufacturers to achieve their end goals and meet the customer’s expectations.
As solutions providers we have relationships with all of the leading manufacturers around the world, these relationships are based on partnership where we provide the flow expertise. Our goal is to deliver the solutions of the future by listening to and understanding the trends in the market now.
One of those techniques is High Pressure Liquid Chromatography (HPLC).
Schematic drawing of a typically HPLC instrument
HPLC stands for High Performance Liquid Chromatography and is a technique used to separate and allow the user to quantify different compounds. A high pressure pump is used to push the solvent through a column, due to the interaction between the compounds and the column material a separation of different compounds is possible. From here you can analyse the time taken to elute the compund ot the amount of compound detected.
Schematic of our instruments installed in the HPLC system
UPLC stands for Ultra High Performance Liquid Chromatography and is a special version of HPLC. Compared to HPLC, UPLC columns contain smaller particles sizes (2 um for UPLC vs 5 um for HPLC), which results in a better separation of compounds. The pump pressure in UPLC can go up to 100MPa in comparison to HPLC where this is 40MPa. UPLC has, in some applications, improved chromatography significantly. The run times are much shorter; therefore very fast analysis is possible. UPLC is the abbreviation mostly used in writing; however this is a trademark technology of one of the major corporations in this field and is officially called UHPLC (Ultra High Performance Liquid Chromatography).
SCFC, the last trend we will discuss today is the growth of research into the way that liquid CO2 can be used as a super-solvent. With the ever increasing cost of chemical solvents used in the mobile phase, both purchase and disposal is increasing yearly. Developing a system that utilizes a solvent, such as CO2, that can elute different compounds and provide a gradient effect purely through adjusting and controlling the system pressure is an incredible potential cost saving development. However as with all things, the cost reduction has to be off-set by the cost of installation of such systems. That day is only getting closer, but we are not yet at the point of wide-spread liquid CO2 solvent usage.
- Working with liquid CO2 can be a real challenge and one that we take seriously, our Coriolis and EL-Press instruments are perfect for this application giving flow and pressure control without the need for a thermal based system that would affect system integrity.
The industry is changing, that’s obvious! We will be on top of this………