Dr. Weimin Liu

Targets of My Study:

I investigate a diverse range of biomarkers to reconstruct (bio)geochemical processes:

• Intact polar lipids: Cellular building blocks used to trace microbial communities and their interactions with their environments.
• Monosaccharide anhydrides and polycyclic aromatic hydrocarbons: Wildfire-derived compounds employed to reconstruct past fire activities.
• Fatty acids and other polar compounds in biodegraded oils: Indicators used to determine the severity of biodegradation.
• Hydrocarbons (e.g., n-alkanes, steranes, hopanes): Applied to trace the source of crude oils and assess the extent of secondary alteration, including thermal alteration and biodegradation.

My recent interest focuses on utilizing comprehensive molecular fingerprinting, encompassing multiple classes of biomarkers, to reconstruct relevant (bio)geochemical processes, often employing methods such as co-occurrence network analysis.

Analytical Techniques:

In addition to standard techniques like GC, GC/MS, and LC/MS, I primarily focus on:

• Mass Spectrometry Imaging (MSI): When applied to sediments, MSI achieves μm-scale spatial resolution in molecular composition changes, enabling high-temporal resolution reconstruction of paleoclimate in laminated sediments.
• Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS): A powerful mass spectrometry technique providing exceptionally high mass resolution and accuracy for molecular measurements.

By combining the high-temporal resolution and rich molecular features obtained from these advanced techniques with other contextual information, I aim to develop machine learning models capable of "predicting" past environmental events and conditions.