Chromatography Forum

But you can change the selectivity in UPLC as well. I am counting 13 different generic UPLC chemistries at Waters, and a range of other people that are making sub-2-micron particles...

Kostas, replacing several old HPLCs with a single UPLC with higher throughput sounds promising but:
in case of different applications one would need a column / solvent switcher
in case of any issues everything is down
some people prefers for some reasons dedicated devices for some applications.

Alex

Alex,

I did not say to replace old HPLCs with a single UPLC with higher throughput. What I did say and I quote myself: "A reasonable approach would be to pay the premium for new HPLC purchases and move to UPLC but I wouldn't invest in switching existing HPLC to UPLC.."

In other words, phase out the HPLCs by buying UPLCs as you get funding for new equipment... What is the premium to pay nowadays for UPLC vs. HPLC?

I am wondering how many people in the pharma industry and in manufacturing are using UPLC. I don't count people from academy (no disrespect to them), beacuse thye need to bring siomething differnet to justify grants and financing. I remember from my days at Pfizer that our analytical people did set up UPLC but after 2-3 month it was collecting dust and everybody went back to Agilent 1100 machines.

Uwe,

I thought the original post wanted to here from end users, not a vendor with an anti-Fused-Core agenda.

And for "scientific purposes", why didn't you cite some of the other invited speakers that presented in the exact same Pittcon session you refer to. Such speakers that are not employed by Waters.

If you are going to speak so vehemently against other companies products, you should disclose in the note your affiliation. Not everyone recognizes your name and affiliation.

Wayne Way - Supelco Product Mgr.

Wayne

I do not have an anti-fused core agenda, I have the facts on my side. I offered the facts so that everybody can review then. I'll send them to you as well, if you want them.

It is very simple, and you or others can try to twist the story as long as they want: smaller particles give a better performance in a shorter time than larger particles. Smaller particles also require higher pressure, which is a disadvantage if you do not have a suitable instrument. But anybody who tries to declare that larger particles are "better" than smaller particles must have his marketing blinders on.

As you can see, this was indeed the case, when my discussion prtners tried to muddy the water by arguing about selectivity. I am not talking about selectivity, I am talking about performance, and that can be measured without trouble.

Wayne, it seems that you are free to cite those "invited speakers" or anything else related. Or in other words, I would be interested to hear what you have to say about why UPLC doesnt "deliver", or whatever.

Vlad, regarding your answer it also would have been much more instructive if you stated why the UPLC was collecting dust.

If i focuse back on the original question:

[quote="rick1112"]Hi
There have been many articles on Poroshell/fused core particle/superficially porous particles. Well I would like to know as users what you all feel about “Poroshell/fused core particle/superficially porous particleâ€

Uwe sugested a paper of his own, please rmeber he works for a company that has a veted interest in STM particles.

A more recent one from AstraZeneca, a more impartial source, makes interesting reading.

"Critical Comparison of Performances of Superficially Porous Particles and Sub-2 μm Particles under Optimized Ultra-high Pressure Conditions"

Wang et al, Journal of Chromatography A Volume 1216, Issue 21, 22 May 2009, Pages 4597-4605

Abstract:

The performance of 2.7 μm superficially porous particles at 600 bar and sub-2 μm fully porous particles at 1000 bar were compared by the Poppe plot method. Theoretical Poppe plots were first constructed for each stationary phase to compare their kinetic performance at different analysis times. The theory was then verified by experiments under the optimized conditions identified from the Poppe plot calculation. We found that the 2.7 μm superficially porous particles at 600 bar can provide similar performance compared to the sub-2 μm fully porous particles at ultra-high pressure (1000 bar) when analysis times are very short (e.g. sub-minute). As analysis time increases, the superficially porous particles start to outperform the sub-2 μm particles and can give much higher efficiencies (e.g. > 2 times higher plate count) at very long analysis times (>3 h). The comparison was extended to gradient elution of a mixture of pharmaceutical interest by constructing gradient peak capacity Poppe plots and similar behavior was observed.

I am very glad that I got into this discussion. Now all the incorrect information is popping up, and I have the opportunity to disprove it.

First of all, woodada's paper. Everybody needs to know that Xiaoli Wang, the first author of this paper, was one of the presenters in the same session at PittCon as I was presenting. In my presentation I disproved the observations that he was presenting, i.e. that superficially porous particles are better than sub-2-micron particles. How did I do that? In my presentation, I introduced the second generation of our ACQUITY sub-2-micron columns. which give a significant performance advantage over the first generation, and now leave the superficially porous particles in the dust. Now, looking at the timelines, the published Wang paper was submitted before PittCon, before the author had an opportunity to look at the Phase II columns that I was talking about. So the paper is old news, without up-to-date information.

Please note that I continue to offer my PittCon presentation to everybody who wants to hear the true and complete story of a comparison of sub-2-micron particles to superficially porous particles. The presentations also show the difference between the older columns, and the Phase II columns.

This is very intriguing discussion. I personally would like to hear all the facts available.
Uwe could you please send me your PittCon presentation you're reffering to?

Thanks,
Zoran

Here is the promised picture of the different particle sizes that was part of the discussion earlier:

http://i40.tinypic.com/dbqjia.gif

Uwe -

Thank you for your discussion and the chromatograms posted on the forum
(though experimental conditions and pressure seems to be missing).

Bryan: here are the details of the c-grams, but it really does not matter. The scaling works independent of the analytes.

Analytes: 1-methylxanthene, 1,3-dimethyluric acid, theobromine, 1,7-dimethylxanthene; mobile phase: 0.1% (v/v) formic acid in 95:5 water/acetonitrile; temperature, 38 degree C, detection: UV at 280 nm, instrument: Waters ACQUITY UPLCTM, with tunable UV (TUV) detector.

hi uwe neue,
i would like to have a copy of your Pittcon presentation...

Now the proponents of superficially poros material will say, wait until our new stuff . . . . .
So how about a bit of theory? I am too lazy to do some calcs here, especially since somebody probably did it already. How much volume of a column is occupied (wasted) by the "inactive" core?
After deciding on the type of surface I always check on the stat. phase surface area (specific) of a column to make a decision. What sort of surface areas do these wasted core columns have?