esteemed collective wisdom, using equilibrium technique (I have a MultiFlow), I wonder if it would be possible to determine D and 18O on the very same sample in two consecutive runs. Idea is loading around 200 microliters of sample + Hokko beads into the Labco vials and equilibrate with H2 mixture, after measurement leaving the samples (and catalyst) in the tray so they don't have to be opened, readjust tray temperature, swap gas mixture to CO2 and run the oxygen measurement. I can't really think a reason why it shouldn't work, but I may miss something.I tested the septa and they seem to hold for various punctures... cheers Chris -- Please consider the environment before printing this e-mail *University of Tasmania │CSL - Isotope Ratio Mass Spectrometry* Dr. Christian Dietz, Facility Manager *│*Private Bag 74, Hobart, 7005 Tasmania ( Tel: (+61) 3 6226 7820, cell phone: (+61) 4 9780 8570 *│*URL: Central Science Laboratory <http://www.utas.edu.au/research/central-science-laboratory> This message is intended exclusively for its adressee and may contain information that is CONFIDENTIAL and protected by professional privilege. If you are not the intended recipient you are hereby notified that any dissemination, copy or disclosure of this communication is strictly prohibited by law. If this message has been received in error, please immediately notify us via e-mail and delete.