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Tailing peaks on ZIC-HILIC

Posted: Mon Feb 14, 2005 11:46 am
by CSV
Hello, everyone!
I'm analyzing ascorbic acid (pka=4.2) on a 150x4.6 mm 5 um ZIC-HILIC column and the analyte is tailing rather bad. The mobile phase is 70:30 ACN:ammonium acetate 100 mM. F=0.5 ml/min.

Does anyone know how to adress tailing on HILIC columns?

Posted: Mon Feb 14, 2005 1:06 pm
by SIELC_Tech
CSV,

Check this out: perfect peak shape, ability to control retention time by two mechanisms:

http://allsep.com/makeCmp.php?cmp=Cmp_149

Posted: Mon Feb 14, 2005 4:31 pm
by HW Mueller
Is that Zic-Hilic that zwitter + who knows what? Could it be that my fears of multi.... columns, like also the Hypercarb, are very unkind to slight variations in mobile phase? If you have a complicated matrix than zillions of compounds always have the wrong conditions? Well just forget them?

CSV, is it possible for you to do these Sielc examples, and could you report on how robust that is?

Posted: Mon Feb 14, 2005 8:57 pm
by Patrik Appelblad
Dear Christian,
It would be much easier to assist you if more of your experimental conditions were known. I'm a bit curious of sample size, sample composition, matrix etc... While I was setting up the separation conditions for Ascorbic Acid and Dehydroascorbate, I did not experience any problems with peak tailing. http://www.sequant.com/products/zichili ... 00-12A.pdf
If you would like to continue this discussion on the forum, I'll do my best to help you, but you are also more than welcome to call me.

/Patrik
SeQuant AB
www.sequant.com

Posted: Tue Feb 15, 2005 7:57 am
by CSV
Hello, again!
Thank's for the replies so far!

Ascorbic acid is tailing in both samples and standard. The sample comprises of dissolved sugar coating, while the standard is pure ascorbic acid. Both are dissolved in and diluted by mobile phase to 0.3-1 mg/ml. The injection volume is 5 ul and the analysis is performed at 25 degrees celsius at 240 nm.

Take care!

CSV