Development and Application of an LC-MS/MS Method for the Analysis of Fatty Acids in a Loess-Paleosol Sequence from Donglingshan, Beijing*

doi:10.7523/j.ucas.2026.004

Abstract

Abstract: This study developed a highly sensitive method based on liquid chromatography-tandem mass spectrometry (LC-MS/MS) for the quantitative analysis of free fatty acids (C₁₀ - C₃₂) in Holocene loess-paleosol sequences. Through systematic optimization of sample preparation (ultrasonic extraction and silica gel column purification), chromatographic separation, and mass spectrometric parameters (MRM mode), 36 fatty acids were efficiently separated and quantified. The method demonstrated low detection limits (0.5 - 15.64 ng/mL) and excellent precision (RSD < 1%). Applied to a Holocene profile from Donglingshan, Beijing, the method successfully identified and quantified several monounsaturated fatty acids (e.g., C_14:1, C_15:1, C_17:1) for the first time in such strata. These short-chain monounsaturated fatty acids typically originate from microbial activity, and changes in their content may directly respond to variations in soil moisture and temperature. Integrating magnetic susceptibility and grain-size data, the vertical variations in fatty acid composition were systematically revealed, indicating their significance for paleoclimate reconstruction. The results suggest that the period from 2965 to 528 cal yr BP was the warmest and most humid of the Holocene at Donglingshan. This research not only fills a methodological gap in LC-MS/MS analysis of loess fatty acids but also provides a new biomarker indicator and technical support for high-resolution paleoenvironmental reconstruction.

Key words: LC-MS/MS, Fatty acids, Loess-paleosol sequence, Paleoenvironmental reconstruction, Donglingshan

CLC Number:

P593

LONG Yujia, LI Yumei. Development and Application of an LC-MS/MS Method for the Analysis of Fatty Acids in a Loess-Paleosol Sequence from Donglingshan, Beijing^*[J]. Journal of University of Chinese Academy of Sciences, DOI: 10.7523/j.ucas.2026.004.

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Development and Application of an LC-MS/MS Method for the Analysis of Fatty Acids in a Loess-Paleosol Sequence from Donglingshan, Beijing^*

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