Characterization of dissolved organic matter from a Greenland ice core by nanospray ionization Fourier transform ion cyclotron resonance mass spectrometry

摘要

Nanospray ionization Fourier transform ion cyclotron resonance mass spectrometry was developed as a tool for examining the dissolved organic matter (DOM) present in ice cores, significantly reducing the sample volume required for extraction compared with previous studies. Using smaller sample volumes is important for resolving temporal changes in ice-core DOM. We demonstrate that a small volume of ice-core meltwater can be extracted and analyzed with sufficient mass spectral sensitivity to describe the molecular composition of the DOM. Two different solid-phase extraction resins (PPL and C_(18)) were compared to examine potential fractionation of the DOM. Over 2500 unique molecular formulas isolated from two different Greenland ice-core samples, dated to approximately AD 1660 and AD 1360, were obtained from the analyses. Method and sensitivity improvements provide an opportunity for organic matter characterization at higher temporal resolution than our previous analyses afforded and allows for examination of ice cores containing low levels of organic carbon.