Could this have to do with phthalates in many pipette tip plastics contaminating your samples?
I faintly remember seemingly similar issues arose in auxin work mentioned in a GC & LCMS workshop I went to.
Date: Thu, 06 Jun 2013 12:55:44 -0400
From: "James J. Campanella" <campanellj from mail.montclair.edu>
Subject: [Arabidopsis] benzoylation of polyamines
To: methods from magpie.bio.indiana.edu, plantbio from magpie.bio.indiana.edu,
arab-gen from magpie.bio.indiana.edu
Message-ID: <d8e384f35718c796.51b086d0 from montclair.edu>
Content-Type: text/plain; charset=windows-1252
I don� know if anyone out there has performed this
protocol, but I am looking for advice. We are trying to determine the
polyamines in some plant tissue samples using a
benzoyl-labelling process and HPLC. Unfortunately, we have run into some
not even gotten beyond the first step of labeling standards.
Analyzing the benzoylated standards on a C18 column using
an isocratic flow of 52% acetonitrile at 1 ml/min, we found no retention
differences between labelled putrescine, spermidine and spermine. We found the
same result using a 50% methanol buffer system.
It is unclear to us whether we are
having problems with the HPLC or whether it is an issue with the labelling
I was worried that we were not
getting any labelling at all so we ran a sample of the benzoyl chloride on the
HPLC just to see what its retention
time may be�nd we found multiple large
peaks. It� entirely unclear to me why a reagent like benzoyl chloride should
have such multiple peaks.
Sigma-Aldrich would not admit there was anything wrong with the product and has not yet answered my grad student's inquiries after a week's
We would appreciate any help or advice that anyone can give.
James J. Campanella, PhD
Department of Biology
Montclair State University
1 Normal Avenue
Montclair, NJ 07043
Alternate email address: jcamp from alumni.uchicago.edu
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End of Arab-gen Digest, Vol 98, Issue 2