Hi Dana,

As Geert has pointed out already, choice of polarity of stationary phase depends on choice of derivatisation.

If you go for an apolar derivatisation (e.g silylation) an apolar stationary phase like a DB-5 would work well. That being said, there are some very good reasons not to opt for silalation in the context of GC-IRMS.

If you go for a mid-polar derivatisation like NAP or ethylformates a mid-polar stationary phase is the column of choice. Irrespective of your final choice being a DB-1705 or a DB-35, be sure to go for the crosslinked if there is a choice between cross-linked and not-cross-linked.

Also note, mid-polar (as well as polar) columns are light and oxygen sensitive. When not in use store the column/s in their box and seal the ends.

Best,

Wolfram

******************************************************
Prof. Dr W Meier-Augenstein, CChem, FRSC
Stable Isotope Forensics & Analytical Sciences

Robert Gordon University
School of Pharmacy and Life Sciences
The Ian Wood Building
Garthdee Road
Aberdeen
AB10 7GJ

E-mail: [log in to unmask]

http://scholar.google.co.uk/citations?user=ty6c5IMAAAAJ
________________________________
From: Stable Isotope Geochemistry <[log in to unmask]> on behalf of Dana Biasatti <[log in to unmask]>
Sent: 02 February 2017 19:52:24
To: [log in to unmask]
Subject: [ISOGEOCHEM] Opinion on GC column for running amino acids?


Hi All,


I was just wondering if those of you that have experience running amino acids on a GC/IRMS could share your column preference. We are trying to decide between a DB-5, DB-35, and a VF-23MS. Thank you very much in advance for your response!!!


Best regards,

Dana



Dana Biasatti
Stable Isotope Specialist
Center for Environmental Science and Technology
University of Notre Dame
Notre Dame, IN




________________________________

This email has been scanned for spam and viruses by Proofpoint Essentials. Click here<https://eu1.proofpointessentials.com/index01.php?mod_id=11&mod_option=logitem&mail_id=1486065274-aiMKcKRdssy4&r_address=w.meier-augenstein%40rgu.ac.uk&report=1> to report this email as spam.


________________________________

Robert Gordon University is the top university for graduate jobs in the UK HESA July 2015


Robert Gordon University, a Scottish charity registered under charity number SC 013781.

This e-mail and any attachment is for authorised use by the intended recipient(s) only. It may contain proprietary material, confidential information and/or be subject to legal privilege. It should not be copied, disclosed to, retained or used by, any other party. If you are not an intended recipient then please promptly delete this e-mail and any attachment and all copies and inform the sender. Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of Robert Gordon University. Thank you.