Dear Wolfram Thanks so much for the quick reply. Happy to share in case someone else has this question in the future. The sample was leaf litter - sorry didn't want to bog down in specifics. The d2H values of the 2 waters were -196.1 and 14.5. And the total 2H values were -177.87 and -177.77, respectively. Best wishes Andrew On 2018-12-19 19:55, Wolfram Meier-Augenstein (pals) wrote: > Dear Andrew, > > > To help you with your question one would need to know a few more > specifics such as chemical nature of the organic solid and d2H values > of the 2 waters A and B used for the exchange experiment for starters. > > You are welcome to contact me off-line if you feel you cannot share > the specifics of your experiment with the list. > > > 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] > > > > ________________________________________ > From: Stable Isotope Geochemistry <[log in to unmask]> on behalf > of A.J. Tanentzap <[log in to unmask]> > Sent: 19 December 2018 19:35:02 > To: [log in to unmask] > Subject: [ISOGEOCHEM] help interpreting 2H exchange exp't > > Dear all > > I've run an exchange experiment on a solid organic as described in > Meier-Augenstein et al. 2011. Rapid Commun Mass Spectrom. > > I estimated the non-exchangeable 2H ratio to be -178. The estimated > fraction of exchangeable H in the sample was 0.0005. > > When I re-run the sample in a bulk analysis, the total (i.e. > exchangeable + non-exchangeable) ratio was -190. > > Would someone be so kind as to explain how this is possible with a > near-zero fraction of exchangeable H? > > Many thanks! > Andrew > > ---------- > > This email has been scanned for spam and viruses by Proofpoint > Essentials. Visit the following link to report this email as spam: > https://eu1.proofpointessentials.com/index01.php?mod_id=11&mod_option=logitem&mail_id=1545248132-5yKLNHey8OjX&r_address=w.meier-augenstein%40rgu.ac.uk&report=1 > > ________________________________ > > Robert Gordon University has been awarded a TEF Gold award for the > quality of its undergraduate teaching and learning, placing it in the > top 20% of Universities in the UK > > > 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.