Table 3. 18O, 2H and17O abundances of 6 highly enriched18O water portions from Rotem (specified as > 98%) and Cortec (> 99%).18O abundances are measured by QMS, between brackets the standard deviation of the repetitions (n) is displayed.2H and 17O abundances are determined via dilution, and measured with our LGR-LWIA, on two different measurement days, and with 9 repetitions per measurement day.
* 2H and 17O abundances of water portion D’ was not remeasured .
Following the determination of the 18O content of the enriched waters, mixing the enriched water with the SLAP replicate to produce SLAP-rep-O was performed. The first approach (only mixing with H218O) was independently performed 4 times, so with 4 different 18O water portions (two from Rotem and two from Cortec, 18O water portion A until D). The second approach (mixing first with2H216O and subsequently with H218O) was performed once with the same 18O water as used in experiment 4 (18O water portion D). As this portion was opened 4 months before using it the second time, the 18O concentration was re-measured by QMS (now D’). The second approach was independently performed with the two remaining 18O waters as well (1 from Rotem and 1 from Cortec, 18O water portions E and F).
An illustration, presented in Figure 5, shows the step-by-step procedure adapted, as described in the sections before, to establish the best δ18O value for SLAP using measurements performed on the LGR-LWIA.
<Figure 5>