Dear Dana

We are following the method of Chikaraishi et al. measuring d15N in N-pivaloyl/isopropyl derivatives of amino acids. We tested out the following columns with some success, HP Ultra 2 (0.52 um film thickness) and a BPX70 but the column we have had the best results with is a Restek Stabilwax-DA, 1um film thickness, 0.32 mm ID. The chromatography is much better with the Stabilwax-DA than the HP Ultra 2. The thicker film also means we are able to load more onto the column.

Best wishes
Rachel

Rachel Jeffreys, Ph.D.
Leverhulme Trust Early Career Fellow
School of Environmental Sciences
University of Liverpool
4 Brownlow Street
Liverpool
L69 3GP, UK

Email: [log in to unmask]
Tel: +44 (0) 151 7954649
Twitter: @racheljeffreys



> On 2 Feb 2017, at 21:11, Wolfram Meier-Augenstein (pals) <[log in to unmask]> wrote:
>
> 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.