Chromatography Forum

Hi All,

We have been told by our regulatory department that we can't/shouldn't be using the acronym UHPLC for our sub 2 micron methods (> 600 bar) when writing methods or regulatory files but should use the acronym HPLC instead. I want to argue that this doesn't make sense really as this would refer to systems/methods with >2.5 micron packed columns with 400/600 bar rated systems.

If I was forced to change then I would prefer to plainly call the technique LC.

What do others think on this? I think we want to get to a place where we don't distinguish between techniques and thus I fell LC fits better than calling it HPLC.

Out of curiosity, what is your regulatory department's reasoning for not using the term UHPLC?

I personally wouldn't refer to the technique as simply LC since you can have low performance/pressure liquid chromatography. I would think the differentiation between ultrahigh performance liquid chromatography and high performance liquid chromatography would be important. That said, it's a nit picky - but inaccurate, in my opinion - request by your regulatory department. The details of the method are going to be included in the regulatory filing so anyone reviewing this CMC section is going to know what specific type of liquid chromatography it is by the method parameters.

Hello,

I agree with Blazer--please choose Not to use LC for the same reason he suggests; LC is simply too general of a term. I agree again with Blazer that is it an inaccurate idea of your regulatory department Not to add UHPLC into your firm's lexicon and I'll add that it is simply Lazy of them as well.

There is a difference between UHPLC and HPLC just as there is between HPLC and low-pressure LC.

I hope that your Regulatory Department reconsiders their position.

I'd guess that the regulatory people have run into a bit of paper that says "purity of X must be assessed by HPLC", so they're stuck if you say "we checked the purity by UHPLC" because someone has to be able to explain to an auditor that they're the same thing.

To be honest, I really regret the existence of terms like UPLC and UHPLC. UPLC was obviously coined as an initially-valid marketing strategy by Waters, but it's become pointless.
We now have a situation where you can run a solid-core particle column of about 3 microns at less than 400 bar and get results indistinguishable from a 1.7 micron particle at over 400 bar. The former is HPLC, the latter U(H)PLC, but there's no discernible difference in the chromatogram or quality of data. That you used a high pressure is an irrelevant technical detail, no more important than the intensity of light used in the diode array detector. Why have two separate terms for technicalities? You might as well have LSL-HPLC (large sampling-loop HPLC) or BCWNLHPLC (blue casework with nice logo HPLC).
And amongst pumps, there are pumps that go up to 400bar, 600bar, and so on, in various steps up to 1300bar and probably beyond. Really, when buying a pump, what you want to know is its actual pressure limits (and corresponding flow rates). It's not one jot helpful to have a terminology that's fixed to one particular threshold pressure. If we must use terms like UHPLC, the future will also hold "EUHPLC" (extra ultra high performance), "SPLC" (sublime performance...), etc. etc.
HPLC has been around long enough to stick. Personally I'd go with the regulatory department and avoid getting embroiled in marketing-driven prefix-wars.

I agree with lmh, the "U" was added simply for marketing purposes to promote a column and pump that could handle a higher pressure and flow than what was currently on the market.

LC is the normal name for what is simply Column Liquid Chromatography, which is usually done with gravity flow or low pressure peri pumps.

HPLC was High Performance Liquid Chromatography(though some refer to it as high pressure)

We now group IC, HPLC, UPLC, and HPLC/MSMS all under the heading of HPLC in our laboratory because they are all the same technology when you get down to the basics of it all.

James and IMH have made some interesting and very valid comments.

My recollections agree with James' comments on the evolution of the nomenclature

From my early experiences in LC, which went from column to HPLC:-)

Column chromatography was the original term we used for gravity fed solvent on a wide column .

Later, when we used low pressure pumps and narrower columns, the common term was simply LC (Liquid Chromatography).

With the introduction of smaller particle sizes/columns and better pumps it was called HPLC - but that had 2 meanings at the time - namely High Performance or High Pressure depending on the manufacturer.

As a note on the use of pre-fixes referred to by IMH see

http://www.techinsider.io/spacex-bigges ... ars-2016-1

or on telescopes see

https://en.wikipedia.org/wiki/Very_Large_Telescope

https://en.wikipedia.org/wiki/European_ ... _Telescope



Regards

Ralph

I see someone resurrected an old post from 2016, though the confusion still exists today. Let us act like knowledgeable scientists, not sales people, and use the correct name, "HPLC".

Recap:
"UPLC" is a Waters trademark only. The technique used is HPLC.
"LC" is NOT HPLC. "LC" is a very generic term for liquid chromatography.
"UHPLC" and "UPLC" were developed as marketing terms only. They are not scientific terms for the technique. The technique is HPLC. As scientists, we should not use marketing names, esp when their is a correct name available. It is "HPLC". Just because you change the packing material, but still run under high pressure conditions makes it HPLC, always... Fully porous, superficially porous, monolithic, irregular, spherical, 1.7 u, 2 u, 5 u, 10u, 20u particles are all types of HPLC supports.
My boss mentioned that back in the 1980's (and 90's to present day), they used lots of different column types and supports; very narrow ID silica tubing, 1 mm ID column, 2 mm ID columns with 3 and 5 micron particles on HPLC systems, some running as high as 100,000 psi !!!! It was always referred to as HPLC. No extra marketing names were needed. Those that are new to the field may not know these things, but the name of HPLC still applies and there is no scientific reason to use silly names such as 'UHPLC' (which is HPLC) for an analytical technique that already has an accurate name. Column details are part of the HPLC method.

Sales people love making up names to make it appear they have a new product to sell (they get paid to do so!). We know better.

More info:
"Terminology. Which is it? UPLC, UHPLC or HPLC? The correct name is still HPLC"; https://hplctips.blogspot.com/2015/08/t ... lc-or.html

That resurrection was "link spam" with a link to an irrelevant web site embedded in copied/pasted text. It has been deleted and the poster has been banned from the site.
When anyone runs across this kind of junk, please let me know so I can deal with it. I usually check the Forum at least once a day, but some of these sneak past