JavaScript requeired.
Geochemical Journal
Geochemical Journal An open access journal for geochemistry
Published for geochemistry community from Geochemical Society of Japan.

Assessing the saponification effect on the quantification of long chain alkenones and the U37 paleothermometer

Jong-Ku Gal, Jung-Hyun Kim, Daun Kim, Sujin Kang, Kyung-Hoon Shin
Geochemical Journal, Vol. 52, No. 6, P. 497-507, 2018


In this study, we evaluated the saponification effect on alkenone quantification and the U37 paleothermometer using two internal standards (2-nonadecanone and squalane) by analyzing in-house reference sediment and eleven surface sediments taken from the Yellow Sea. The C37:3 and C37:2 alkenone concentrations of the in-house reference sediment showed significant differences between before and after the saponification (ΔC37:3 and ΔC37:2) depending on the internal standards used. However, the differences in the U37 and the estimated sea surface temperatures were insignificant. The ΔC37:3 and ΔC37:2 concentrations were larger when calculating based on 2-nonadecanone (46 ± 26 and 136 ± 67 ng/g, respectively) than those based on squalane (–7 ± 4 and –12 ± 10 ng/g, respectively) in the surface sediments. Interestingly, the ΔC37:3 and ΔC37:2 concentrations based on 2-nonadecanone showed a strong correlation with the loss of 2-nonadecanone that occurred during saponification. Accordingly, our study indicated that preferential loss of internal standards (e.g., 2-nonadecanone) can occur during saponification, which affects alkenone quantification and, thus, attention should be paid when choosing an internal standard.


alkenones, U37, sea surface temperature, saponification, Yellow Sea

All Issues

Current Issue:
Impact Factor: 0.8 (2022)
Submission to final decision: 9.6 weeks (2022)
Geochemical Society of Japan

page top