Fig. 7. Comparison of the m /z 28, 29 and 30 traces in the sequence of consecutive measurements of NBS28_FO6. Red arrows represent the positions of CO peak ends.
The oxygen yields and δ18O values obtained from samples with different recipes are summarized in Table 3. Note that the samples showing the anomalous yields described above (sample run order #16–18, #24, #32, #40, #48, #57, and #66 in Fig. 6) were removed from this summary. Based on the observed δ18O of standards (NBS18, IAEA-601, and -602) and their reference values, a calibration curve was determined as follows:\(\delta^{18}O_{\text{reference}}=1.00588\times\delta^{18}O_{\text{observed}}-0.00587,\ R^{2}=0.99998\)(Fig. 8). Then, δ18O of the silicates were calibrated. Table 3 also shows 1σ of standard deviation of yields and δ18O values.
Table 3. Oxygen yields and δ18O of silicate samples at different method