Analysis of vanillic acid in polar ice cores as a biomass burning proxy – preliminary results from the Akademii Nauk Ice Cap in Siberia

• Main Authors: Grieman, M. M., Jimenez, R., McConnell, J. R., Fritzsche, Diedrich, Salzmann, E. S.
• Format: Conference Object
• Language: unknown
• Published: AGU 2013
• Subjects: Arctic; Severnaya Zemlya; Climate change; Ice cap; Siberia
• Online Access: https://epic.awi.de/id/eprint/34572/; https://hdl.handle.net/10013/epic.42786

Biomass burning influences global climate change and the composition of the atmosphere. The drivers, effects, and climate feedbacks related to fire are poorly understood. Many different proxies have been used to reconstruct past fire frequency from lake sediments and polar ice cores. Reconstruction of historical trends in biomass burning is challenging because of regional variability and the qualitative nature of various proxies. Vanillic acid (4-hydroxy-3-methoxybenzoic acid) is a product of the combustion of conifer lignin that is known to occur in biomass burning aerosols. Biomass burning is likely the only significant source of vanillic acid in polar ice. In this study we describe an analytical method for quantifying vanillic acid in polar ice using HPLC with electrospray ionization and tandem mass spectrometric detection. The method has a detection limit of 100 pM and a precision of ± 10% at the 100 pM level for analysis of 100 μl of ice melt water. The method was used to analyze more than 1000 discrete samples from the Akademii Nauk ice cap on Severnaya Zemlya in the high Russia Arctic (79°30’N, 97°45’E) (Fritzsche et al., 2002; Fritzsche et al., 2005; Weiler et al., 2005). The samples range in age over the past 2,000 years. The results show a mean vanillic acid concentration of 440 ± 710 pM (1σ), with elevated levels during the periods from 300-600 and 1450-1550 C.E.