A Novel Approach To Analyzing Dissolved Organic Matter In Ice Core Samples By Fourier Transform Ion Cyclotron Mass Spectrometry

摘要

The molecular composition of dissolved organic matter (DOM) is a topic that has been growing in interest over the past several years with the advent of many new sophisticated analytical methods, especially ultrahigh resolution mass spectrometry [1]. Unfortunately meltwater from ice cores contains low concentrations of DOM, and this has provided a challenge to those interested in dissecting ice-core DOM for answers relating to past climate and hydrological conditions [2]. Concentrating the DOM from water has traditionally been accomplished by use of resin adsorption, typically XAD or C18 [3]. For such low concentrations to provide sufficient material for analysis, researchers have resorted to use o large volumes, but large volumes of water from ice cores are not reasonably obtained Moreover, it has recently been demonstrated by our group that the C18 adsorption method selectively excludes certain types of compounds and recovers less than 50% of the DOM. Fo the past several years, we have sought to employ approaches that minimize the loss of DOM compounds during isolation or allow us to directly analyze DOM at natural abundance [4] We report here, for the first time, the ability to directly analyze ice-core melt water by Fourie transform ion cyclotron resonance mass spectrometry (FTICR-MS) using only rotary evaporation as a concentration method.