Acclaim surfactant column

[push]

I have seen a prospect about Acclaim surfactant column of Dionex. It seems to be good for quaternary amines. What about a ternary one? Can I separate the quat and the ternary amine using this column?

[SIELC_Tech]

You can separate them if they are hydrophobic enough for retention by rp mechanism. It should have retention on rp column. If your quat and tertiary amines hydrophilic you will not have retention or separation (some of amines you will not retina on this column: paraquat and diquat, tetraethyl ammonium, tetraethyl ammonium).
How hydrophilic are your amines?

[XL]

Acclaim Surfactant column is the most suitable column in the market for cationic surfactant separation (http://www.dionex.com/en-us/products/co ... 71771.html). To put it in a broader applications area, this column works well for hydrophobic quaternary amines that have more than 12 alkyl carbons. For less hydrophobic quaternary amines, you can consider using Acclaim Trinity P1 column (a cation-exchange/anion-exchange/reversed-phase trimode column. http://www.dionex.com/en-us/webdocs/707 ... 239-02.pdf).
I am interested to know if you have any specific challenges at hand so that I can be more helpful. Please feel free to contact me if you have any questions regarding Dionex Acclaim columns.

[push]

I am iterested in separation of morfolin and its quat.

[XL]

Morfolin is too hydrophilic to be retained on the Surfactant column. You need a cation-exchanger for this molecule. The separation of morfolin and its quat shouldn't be too difficult, but the detection can be challenging. UV is not an option due to the lack of chromophore. RI is possible but sensitivity can be poor. Morfolin is too volatile to be detected by CAD or ELSD unless TFA is used in the mobile phase. In this case, you need to select a proper stationary phase (column). If MS is available to you, then the detection issue is simple - a cation-exchanger and a volatile mobile phase at the pH both where analytes are positively charged should do the trick. Good luck.

[SIELC_Tech]

primesep 100 or Primesep 200 mixed-mode column with acetonitrile/ water/ tfa and ELSD will do the job. Here are references. You need a weaker column then primsep A column:
http://www.sielc.com/compound_070.html
http://www.sielc.com/compound_086.html

Contact me if you have questions.

[push]

Thank you Xiaodong,
What about N-Methylmorfoline?

[SIELC_Tech]

You are not going to retain n-methylmorpholine on Acclaim column, and it will not going to retain quat of morpholine with small amount of carbons. You are not going to see NMM on Trinity column unless you use lc/ms, ri, or nitrogen detector. With TFA you are not going to retain it on Trinity column and it will come in pre-void, which you will see on ELSD. Trinity will give you retention with ammonium formate, acetate or corresponding acids with pH above 5.

[Bintang]

As the previous posters have stated Ion exchange is one option that may work, perhaps you will get enough separation between the quat and the protonated amines.

The compounds are hydropillic so you will get retention in HILIC, we have the following application on quats.
http://www.sequant.com/files/documents/ ... piquat.pdf

The retention will be a combination of hydropillic partitioning and ion exchange, at low pH the ammines will be protonated so they should have good retention. Any methyl groups will have large impact on the partitioning so selectivity should be good.
If you have any questions regarding HILIC please do not hesitate to contact us at

chromatography@merck.de or
support@sequant.com

[HW Mueller]

Petrus, are you now acknowledging that there can be ion exchange with SiO- of Zic-HILIC?

[Bintang]

The ion exchange I was refering to was with the sulfonic acid group of the sulfobetaine group.
The ion exchange with silanol groups is not an issue with the ZIC-HILIC since the polymeric version the ZIC-pHILIC has almost identical selectivity and that retention does not really change with pH unless the analyte is affected.
I was not beeing clear on my last post low pH means low enough to ionize the amines.

[HW Mueller]

The sulfabetaine is a zwitter, it has characteristics which can not simply be described via an isolated negative charge and an isolated positive charge.
Your silica based ZIC-HILIC has plenty of SiO- somewhere near and above pH = 6. I have mentinoed unequivocal proof of this several times, you can repeat those experiments very easily. The evidence you present here to the contrary is self delusion since you are swamping the silanol effect via an ionic strength effect.

[SIELC_Tech]

There is no ion-exchange on ZIC hilic column related to sulfonate. Quat and sulfonic acid are too close to each other to "allow" any ion-exchange, in particular with much weaker base like morpholine. You MIGHT see some ion-exchange for sodium ion, but not for organic bases. It might be hard to separate ion-exchange for sodium coming from sulfonate or silanols. In order to see ion-exchange interaction you need to separate acid and base by long hydrophilic chain, like it is done on Obelisc N HILIC/mixed-mode column:
http://www.sielc.com/Products_Obelisc.html

All retention of morpholine on Sequant column comes from HILIC and very minor silanols (at pH above 6)

[Bintang]

It is true that the ionic interactions between ionic species and a sulfobetaine zwitterion is not a traditional ion exchange it is much weaker but the effect is there and it has very little to do with silanols. However I do not think the original poster is interested in this semantic differance he wants to get ideas on how to separate his compounds.

As to where the ionic interaction comes from I find it difficult to believe that also our polymeric columns (ZIC-pHILIC) should have such high amounts of dissosiated silanols that we would se substantial ionic interactions with them. There have also been published a large number of scientific papers separating inorganic ions using both the ZIC-HILIC and the ZIC-pHILIC and the strange thing is that changing the eluent ionic strength and water content has an impact on the retention of both anions and cations the only rationale for this behaviour is ionic interactions and HILIC.
HW Mueller I would be very interested in geting the reference to the paper in question.

[HW Mueller]

Vlad, as I have described before it is very easy to demonstrate silanolate activity of ZIC-HILIC, for instance, with 22Na+. It comes through at ~tm, mobile phase ~pH 2, gets stuck at the beginning of the column (22Na is a positron emitter, so one can easily measure the gammas coming through the column) at ~pH 6. It behaved almost identical to an Atlantis Silica column in this respect. Of course, you need low ionic strength mobile phase to see this.

Petrus, I have not published this yet, I mentioned some of the experiments here, they are a joke of simplicity, you can do this in a few hours. Get a good pure silica column for comparison, you will hardly see any differences.
We are NOT talking about semantics, this is chemistry. If the sulfonate would be responsible for ion exchange, why would there be this pH dependence?