cis- and trans-cypermethrin

[marinamax2000]

Hi everyone........

I´m looking for a column that will resolve cis- and trans-cypermethrin isomers........ any suggestions?

Thanks,

[mstolk]

Hi,

We're analyzing cypermethrin on a HP5-MS column.
We find 4 peaks for cypermethrin, problably 4 different isomers.
It al depends on the GC-program. Our Gc-run is aproximatly 45 min.

[jh1]

Hi,

We're analyzing cypermethrin on a HP5-MS column.
We find 4 peaks for cypermethrin, problably 4 different isomers.
It al depends on the GC-program. Our Gc-run is aproximatly 45 min.

We've also had luck with HP1, HP50 columns.

[marinamax2000]

Hi mstolk and jh1.....
thanks for the input....
I have performed an intensive search on the subject and found that chiral separation of Alpha-Cypermethrin and found that:

Alpha-Cypermethrin can be separated on the BGB 172 column, but only the enantiomers of the cis diastereomers can be separated, giving a maximum of 6 out of 8 isomers........

So, HP-5 gives 4 peaks and BGB-172 (betacyclodextrine based) gives 6 isomers.... I´m still looking for a system that will separate all 8 isomers........

The method was published by Weiping Liu J. Agric. Food Chem. 2004, 52, 755-761