Separation of poistional isomers 2,4,5-Trifluorophenyl aceti

Discussions about HPLC, CE, TLC, SFC, and other "liquid phase" separation techniques.

4 posts Page 1 of 1
Hellow Experts,

I am working on separation of 2,4,5-Trifluorophenyl acetic acid and its positional isomers on RP HPLC. Any body have some of literature regarding to separation of positional isomers or some valuable suggestion so that I can get proper separatioin

Best regards
Praveen, you can separate positional isomers with our mixed-mode columns. These can be either acidic, basic or zwitterionic compounds: ... zoic-acid/ ... conditions

Contact me through our website if you have questions.
Vlad Orlovsky
HELIX Chromatography
My opinions might be bias, but I have about 1000 examples to support them. Check our website for new science and applications
Thanks Vlad for your for your suggestion. Un fortunately these columns are not with us. I have also performed the exercise on CN column. I am getting much positive results. and getting good separation. Two isomers are overlaying on each other which are very well separated on GC. Three isomers are separated each other. SO for this sample analysis I am performing two exercise. One is GC and other is HPLC.

I required some more and suggestion which gives me very well separation with sharp peak shapes

Hi Praveen,

I would definitely take Vlad's suggestion more seriously-- separating isomers is a feature specific to specific columns. Separating some isomers will be possible on standard common columns like the CN or C18, but for better resolution a chiral selector is usually the way to go. I've had success separating diastereomers on a PFP(2) column from Phenomenex, but it could not resolve their enantiomeric pairs (4 diastereomers, 4 enantiomers) and would come out as the pairs of diastereomers. The PFP is marketed as a column that has some chiral separation, but clearly not enough in my case. We went through their screening process and found a chiral column that could split these pairs and we're now able to get all of the products efficiently. Positional isomers may be more difficult due to the subtle differences observed between the molecules, which may mean that you have to bump up your chromatography to that next-step. Alternatively, you could purchase (find, if you have some available) some chiral mobile phase additives which is a good alternative to purchasing a new column (depending on intended use of course). It sounds like you have them mostly separated, and depending on if you're running a gradient or not, you may be able to tweak the ratios of your mobile phases slightly (probably extending the overall run-time of your method) in order for your compounds to interact with the column more, and hopefully enhance your resolution. From what you said, it seems like you are able to separate them sometimes, and sometimes they come out as a single peak, this indicates to me that you could probably separate them but it depends on the gradient of your mobile phase.

As always, any conditions, mobile phase details, potential columns, etc. would be very welcome and help us assist you to reach your goals!

Thanks for reading
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