Table 3.

Published Values of ETH Standards Projected to 25 °C, and Number in Parenthesis Is the Number of Replicates

Standard	This study: MAT 253, 70°C Kiel IV device Porapak without He flow. AFF: 0.062.	Daëron et al. (2016), Isoprime 100 common acid bath, 90°, Porapak trap with He flow. AFF 0.082	Schauer et al. (2016), MAT 253, 90° common acid bath, AFF: 0.082	Breitenbach et al. (2018), MAT 253, 70 °C Kiel IV device Porapak without He flow. AFF: 0.062.
ETH‐1	0.258 ± 0.003 (82)	0.311 ± 0.006 (18)	0.286 ± 0.006 (8)	0.265 ± 0.002 (279)
ETH‐2	0.256 ± 0.004 (83)	0.306 ± 0.007 (13)	0.282 ± 0.005 (12)	0.253 ± 0.002 (292)
ETH‐3	0.691 ± 0.004 (73)		0.695 ± 0.009 (6)	0.693 ± 0.002 (267)
ETH‐4	0.507 ± 0.004 (83)		0.537 ± 0.006 (7)	0.503 ± 0.003 (324)

Note. The different fractionation factors are due to the fact that Daëron et al. (2016) and Schauer et al. (2016) used a reaction temperature of 90°C, whereas Breitenbach et al. (2018) and this study reacted the carbonates at 70°C. AFF = acid fractionation factor used to project the results to 25°C.