Chromatography Forum

Hello

Our laboratory is new to quat analyses especially for these compounds. We don't have LC/MS capability. We have experimented with the EPA ion pair methods by LC-DAD, but of course mepiquat doesn't have a decent chromophore. There appears to be literature evidence that perhaps conductivity or ELSD detection is more appropriate. Anyone have detector, column and/or mobile phase suggestions?

Mike

http://www.sielc.com/Compound-Mepiquat.html (contact ChromForum user Vlad Orlovsky for more details about SIELC columns).

Here are also paraquat and diquat and reference for analysis using our Obelisc R column. This method was validated in Europe and isused globally. If you don't have LC/MS you can use ELSD for mepiquat and UV/ELSD for paraquat and diquat:

http://www.sielc.com/Application-HPLC-S ... isc-R.html
http://www.conffidence.eu/img/page/home ... oster7.pdf

Here is a link to part numbers and prices. If you want to use ELSD or UV go with 3.2x150 mm column.

Contact me if you have questions.

Thanks Vlad

Do either of these methods have all three targets in them?

Mike

I don't know, but I am 99% sure that it will work. You will need to use gradinet of buffer concentration or gradient of buffer pH, because mepiquat is monoquat and PQ and DQ are diquats. Do paraquat search in Google and see how many people refer to Obelisc

Here is another great reference, see page 13-15. We sell tons of these columns to environmental, food labs and herbicides manufacturers
http://www.crl-pesticides.eu/library/do ... CrlSrm.pdf

If you are from ECCS (Madison) your company purhased one of Obelisc R columns couple of weeks ago.

Vlad

We are from ECCS and we have been struggling with seeing mepiquat. We just purchased an ELSD that will show up next week. With your column hopefully the three will work. Thanks.

Mike