By Anonymous on Thursday, October 30, 2003 - 01:38 am:
Hello at all,
I'm searching a method for analyzing chlormequat (plant growth regulator) from matrices of vegetal origin.
All methods that I have found do not consider a purification step (SPE) except one that use gel permeation (not avalaible in our laboratory).
There is an SPE-SCX method?
Have anyone tried chromatographic separation of chlormequat on porous graphitic carbon column?
We search an alternative to ion exchange or ion pair separation. In particular ion pair separation is difficult to perform with ESI-MS detection.
Any input is greatly appreciated.
Thanks in advance.
By Zelechonok on Thursday, October 30, 2003 - 07:41 pm:
Check this application: Quaternary Amines Separation
http://allsep.com/makeChr.php?chr=Chr_007
This method was developed specifically for quaternary amines. It uses TEA acetate. Even it is not common for MS applications to use TEA the method is MS compatible. The column is Primesep C.
By MG on Friday, October 31, 2003 - 08:51 am:
Zelechonok, that apps note shows ELSD detection. Has this method been tested with MS? If so, what sort of detection limits were obtained?
By zelechonok on Friday, October 31, 2003 - 07:46 pm:
This method was tested with MS Agilent 1100 (single quad).
Unfortunately, I can not tell, you exactly limit of detection. Total ions chromatogram that I have shows about 100 : 1 ration of signal to noise at concentration of quaternary amines 0.3 mg/mL and injection volume 5 uL. If you set your detector to specific ion the LOD should be much better. Also Primesep 100 (4.6x150 mm) with mobile phase MeCN/H2O/TFA-20/80/0.05 can be used and gave retention for Me4N+…5 min; MeEt3N+ …10 min; Et4N+…13 min. Base line resolution suggests to use shorter column. Probably 50 mm column will be sufficient. TFA system gave asymmetrical peaks with symmetry about 0.5 in these conditions, which, probably is not important in your case.
E-mail me your address and I will send you the pictures.
yury.zelechonok@allsep.com