AVS 66th International Symposium & Exhibition
    Biomaterial Interfaces Division Tuesday Sessions
       Session BI-TuP

Paper BI-TuP5
Mass Spectrometric Determination of Active Adsorption sites of soil organic Carbon on Clay Mineral Surface

Tuesday, October 22, 2019, 6:30 pm, Room Union Station B

Session: Biomaterial Interfaces Posters/Flash Session
Presenter: Zihua Zhu, Pacific Northwest National Laboratory
Authors: Z.H. Zhu, Pacific Northwest National Laboratory
L. Huang, Pacific Northwest National Laboratory
W. Liu, China University of Geosciences, Wuhan
Correspondent: Click to Email
The heterogenic active adsorption sites on mineral surfaces may harbor critical determination on the protecting capability, preference and efficiency on soil organic carbon (SOC) components. Molecular evidence to show organic behaviors during mineral-microbe-organic interactions is urgently needed to reveal the underlying protecting-releasing mechanism for better prediction on the SOC dynamics. However, such information has been hard to obtain in the complex soil systems. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is a powerful surface analysis tool with unique advantages to reveal systematical changes of both SOC and mineral surfaces during mineral-microbe-organic interactions. In this work, ToF-SIMS and principle component analysis (PCA) were used to study the molecular mechanisms of organic preference (e.g., humic substances vs. microbial carbon) by Fe-rich clay mineral (e.g., nontronite NAu-2) during microbial Fe redox processes. Active adsorption sites, which have only been hypothesized or computationally investigated in previous research, were successfully determined by ToF-SIMS data. Such a success indicates a bright future of extensive application of ToF-SIMS and PCA on this field.