Biggest Breakthrough in HPLC in 25 years!

[Bill Tindall]

interesting. now my curiosity has been aroused enough to check the web site.

[ConstantinS]

Pitily, I can't put the information at your disposal for it is closed. However, Dionex multimode columns act in the same way.
Polymeric phases have certain advantages over silica-based. Durability is the most important. Here I'm talking about highly cross-linked (or even hypercrosslinked) phases with excellent rigidity and high efficiency (not lower than 50K per meter).
I vote for polymeric ones. But there is another parameter affecting the choice: price.
Polymeric ones are more expensive. We can, for example, compare price for Primesep and IonPac columns... let it be 250x4.5 5mkm in USA.
What do you think, can we?

[SIELC_Tech]

Constantin,

Most of the silica based RP columns (including mixed mode Primesep) provide 75-100K plates for 5 um particles. Some manufacturers claim 120K but I believe they are using 4.2-4.5 particles.
Price for 4.6x250 mm Primesep column is $698, but we are barely using them. You can achieve desired separation with much shorter column. All our method development work is done on 50 or 150 mm columns. You have more parameters to adjust selectivity of the column (organic, buffer concentration and nature, pH). I do not know how to post picture here but I have really good one on orthogonal nature of Primesep columns.

[ConstantinS]

Dear SIELC!

Can you tell me your name 'for it is rather hard to communicate with a company?

Sure, the efficiency of silica-based columns is higher in all cases. But I just wanted to say that efficiency of 50K is high enough to carry on rather complicated separations.

You don't need to post pictures for I have already read all .pdf catalogues.

So, it is Chis's turn now to tell the price for 250x4.6 multimode IonPac

[ConstantinS]

As for my previous work, it concerned another type of multimode columns.
Mixed (reversed phase)-(quasi-normal phase) neutral polystyrene ones. In hexane-based eluents the retention is due to pi-interactions, and in water-rich eluents the elution order corresponds to RP one. Besides, all intermediate modes are possible (on chloroform-methanol eluents, for example). This information is not closed, it is published at web-sites and in J.Chromat.A.

[Chris Pohl]

Constantin,

You are correct in that prices are generally higher for polymeric columns and efficiencies are often higher for silica based media but efficiency is only part of the game, as you suggest. As I like to say: selectivity rules, efficiency drools. As far as a specific example of pricing is concerned, prices differ in different countries but the US list price for a 4 x 250 mm OmniPac column is $950. Another material difference between polymeric and silica based media is column life. While column life is dependent on a great many different parameters including the nature of the sample, sample prep, eluents used and instrument operating conditions, in general polymeric media will achieve significantly more than double the average life of silica based media. In fact, it's not uncommon to hear from a customer who's been using the same polymer based product for 5-10 years.

[ConstantinS]

Thank you, Chris, for proving my suggestions.

To sum up our little research work... Assuming the selectivity of both silica and polymeric multimodal columns equal (or comparable), the latter give about 50K and double lifetime for 1000$ as compared with silica-based ones, which give about 80K and "single" lifetime for 700$. Polymeric columns seem to be more attractive, bu often they seem strange to a customer... but it is a question of time (how does this idiom sound in English?)

By the way, Chris, did you get my e-mail concerning on-line journal on anchem.ru? It would be interesting to see your publication (in fact, a kind of shot review of modern Dionex phases will be enough). I want to make the first issue to April 19, when the largest analytical exhibition in russia AnalyticaExpo-2005 will take place.
Besides, I will discuss there some plans with people from Abacus, russian distributor of Dionex production.

[SIELC_Tech]

Constantin,

I am not sure that a lot of people in pharma industry are looking at the price difference or the column which will outlive the analyst. I spent 10 years in big pharma and do not know a single person who made his decision on the column supplier based on the price alone. The main criteria is reproducibility from run to run and from batch to batch, selectivity, efficiency, peak shape, etc. It is hard to make a conclusion about efficiency and selectivity of the column based on assumption. You need to screen probably several different compounds/mixtures and see how good is separation in terms of efficiency, selectivity, peak shape, compatibility of the method with LC/MS and prep chromatography, etc. If you have any particular set of application in mind we can compare it side by side and see advantages of both technologies.

[Chris Pohl]

Constantin,

Sorry for the slow response to your email but I'll send you a detailed response when I'm back in the office on Wednesday. I'm interested but don't know if I can meet your deadline