One of the biggest mistakes you can make when learning how to perform liquid chromatography (HPLC) is trying to force a method to work on a single column type that is not appropriate. Many novice users waste a tremendous amount of time and materials (solvents and related consumables) doing this. Columns (which are consumables) are inexpensive compared to the costs of the instrumentation, supplies and time spent so if the column does not yield good results with appropriate methods, then try a different column.

As previously noted by others, there is no such thing as an " universal " C18 column. Just as with mobile phase selection, flow rate, % composition, temperature, pH and time, columns types are one of many variables in method development. There are thousands of variations in C18 style columns today. Please base your initial column choice on your actual intended application and move forward from there. It should be "fit for purpose".

If possible, set up and use an automated HPLC column and mobile phase screening system to find the best column and mobile phase composition for your method (*When properly setup by an experienced chromatographer, this approach will provide the fastest route to a suitable method).

You may want to look into Waters, Agilent or other suppliers' guide for column selection:

https://www.waters.com/webassets/cms/library/docs/720001983en.pdf

https://www.sigmaaldrich.com/catalog/search?term=hplc+columns&interface=All&N=0&mode=match%20partialmax&lang=en®ion=IQ&focus=product&gclid=EAIaIQobChMI34WW-pmC4gIVg9KyCh1cigeSEAAYBCAAEgJGA_D_BwE

There is no universal C18 column that can do everything. But in the 1980's I only had to use my Spherisorb column to perform routine vitamin analysis. Depends on what you want to analyse and the challenge of your sample matrix.

I don't know if I would select the same column today since it was 10 um particle size (I don't even know if they make that size anymore). Remember, the smaller the particle size the higher the retention capacity which means you only see a smaller part of the chromatographic separation since more molecules will be retained on the column. I would buy an old 1100 or 1200 and a robust 5 cm x 4.6 mm C18 column and if I encounter the above problem go gradient. Use DAD and MS detectors in tandem and formic acid in the mobile phases.

Fahimeh Mahmoodi, before even starting to evaluate a column's selectivity the first step is to identify the analytical need. So, what is to be determined, at what concentration in what matrix... Be specific with that evaluation.

Then you would check the internet, library, forums like this for similar or identical applications, which can be used as a blueprint for your work.

Most vendors have their column catalogs, and usually, you find a comparison table describing how what column matches others. Articles in literature also provide excellent comparisons - take your time defining your analytical needs. Once that is done, your choice is influenced by the analytical instrument you have available: Older instruments usually have lower backpressure specifications, and newer small particle columns require higher backpressure.

An excellent compromise (and I am a big fan!) is to use what it called "fused core", "solid core", "accucore" material which comes with a specially treated core particle, that is showing small (micro) pores, so that the migration of the analyte into the "heart of the particle" is minimized. Such stationary phases exhibit low backpressure and excellent efficiency. They are available with different selectivities, and this closes the circle back to the beginning of this message.

Not much of a shopping list, I know. However, I think selecting a column is a bit more delicate and requires some additional thoughts.

Still, I hope this is of help.

Good luck with your research and your experiments,

Detlef.

P.S.: One tool (a free of charge library) that I like pretty much is this:

https://appslab.thermofisher.com/

I usually use it as a starting point for my evaluations.

My experiences in HPLC suggest that good columns are obtainable from Develosil (Nomura Chemical Co., Seto-city, Aichi, Japan) and Nucleosil (Macherey, Nagel & Co., Düren, Germany). Please see files; Lysozyme by RP-HPLC and JCB Fucoidan transport.

It is interesting that an engineer of Nomura Chemical Co. has come to meet me to my Institute (Division of Endocrinology and Metabolism, National Children’s Medical Research Center, Taishido, Setagaya-ku, Tokyo) after the publication of my General Protein determination method (please see article; HPLC-Surf-SEC Protein determination method).

Select column that accept 100% water content in eluent. It will enlarge the spectrum of possible applications.

Regards

G

One of the biggest mistakes you can make when learning how to perform liquid chromatography (HPLC) is trying to force a method to work on a single column type that is not appropriate. Many novice users waste a tremendous amount of time and materials (solvents and related consumables) doing this. Columns (which are consumables) are inexpensive compared to the costs of the instrumentation, supplies and time spent so if the column does not yield good results with appropriate methods, then try a different column.

As previously noted by others, there is no such thing as an " universal " C18 column. Just as with mobile phase selection, flow rate, % composition, temperature, pH and time, columns types are one of many variables in method development. There are thousands of variations in C18 style columns today. Please base your initial column choice on your actual intended application and move forward from there. It should be "fit for purpose".

If possible, set up and use an automated HPLC column and mobile phase screening system to find the best column and mobile phase composition for your method (*When properly setup by an experienced chromatographer, this approach will provide the fastest route to a suitable method).

Be careful on what you promised to analyse. ‘You can’t be all things to all men’.

I would suggest getting your column and analysing selected products like orange juice for Vitamin C and feed premixes for Vitamins A, D, and E. Take these chromatograms and display them to various lab managers as what you can do. They are always looking for inexpensive outside contract laboratories they can count on.