A method is presented for the chemical characterization of natural organic matter (NOM). We combined reversed-phase chromatographic separation of NOM with high resolution inductively coupled plasma mass spectrometry. A desolvation technique was used to remove organic solvent derived from the preceding chromatographic separation. We applied our method to solid-phase extracted marine dissolved organic matter samples from South Atlantic Surface Water and Antarctic Surface Water. The method provided a direct and quantitative determination of dissolved organic phosphorus and sulfur in fractions of differing polarity and also allowed simultaneous speciation studies of trace elements. Dissolved organic carbon:phosphorus and carbon:sulfur ratios for the different chromatographic fractions of our two samples ranged between 341 – 3025 for C:P and 11 – 1225 for C:S. Differences in elemental distribution between the fractions were attributed to different biochemical environments of the samples. Sulfur was exclusively found in one hydrophilic fraction, while uranium showed a strong affinity to the hydrophobic fractions. Our method was designed to be easily adapted to other separation techniques. The elemental information will deliver valuable information for ultrahigh resolution molecular analyses.