Dear AllBack to the Top
We are trying to quantify metabolites formed in vivo (rat plasma, bile,
urine and feces samples) by LC-MS of NCEs. Can anyone suggest regarding the
sample preparation and clean up so as to minimize interferences.
Hello Mr. BansalBack to the Top
You may use liquid-liquid extraction methods or solid phase extraction
methods for purification of the bio-samples. You may also use precolumns
like RAMs ( restricted access material) for sample clean-up. You can find
many articles in pubmed.org related to these methods. Below are the few
references i found in pubmed.
Biomed Chromatogr. 2004 May;18(4):248-53
J Pharm Biomed Anal. 2004 May 28;35(3):639-45.
J Pharm Biomed Anal. 2003 Aug 8;32(4-5):829-38
Probably you may find better methods in other published articles.
University of Missouri-Kansas city
Kansas city , MO 64110
Hi Tripta,Back to the Top
You need to be very careful and do minimal sample cleanup because the
nature, number and concentrations of metabolites present are unknow (
for a NCE). It is therefore impossible to determine if any will be lost
during a sample preparation procedure. You can simply centrifuge the
neat urine and bile samples to remove any particulates and inject the
supernatant directly onto an analytical LC column. This method will
minimize metabolite loss in early stages of study and is fast. Later
you can follow the suggestions of Mr. Sriram once you have a clear
hope it works well.
Dr. Jagdish Jaiswal, PhD
Research Associate, Pharmacology (Drug Discovery)
Torrent Research Centre, Gandhinagar, India
I agree with Jagdish that there should be a minimumBack to the Top
sample clean up. You can clean up urine samples by
passing through a small sephadex column to get rid of
salts,particularly if you intend to inject samples in
When I compared this procedure with ethyl acetate
extraction, the metabolites appear to be entirely
different.Stability is an issue here.
Dr. Sunil bajad (Patil)
Department of Medical Sciences
School of Vet. Medicine
University of Wisconsin-Madison,
2015 Linden Drive west,
Madison 53706, WI,USA
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