Phthalate Esters

[wheeltops]

Anyone have any experience of these compounds? They're pretty easy to separate on a 5 type phase column but my problem is with a Restek standard phthalate mix in which the 6th peak - Bis(4-methyl-2-pentyl)phthalate - splits. I've done all the usual stuff to solve this kind of issue but it's still splitting.

Does anyone know why this particular phthalate presents a split peak and if there are any fixes for it?

Thanks for your help.

[krickos]

Hi

I some cases the standard mix contains isomers so have you checked it against a chromatogram supplied by the supplier?

Check the split peak nr 7 in this link for example:

http://www.sigmaaldrich.com/Graphics/Su ... /11734.pdf

[wheeltops]

Ahh...... It's all clear now.

Thanks for that, I'd found three other chromatograms of the mix on the web and all contained the split peak but none listed them as isomers.

I'll stop wasting my time trying to separate them now and get on with something more attainable.

Thanks, I appreciate your help.