FLUORESCENCE CHARACTERISTICS OF REVERSE-PHASE HPLC FRACTIONATED MARINE ORGANIC-MATTER

Fluorescence emission spectra, recorded at different excitation wavele ngths (lambda(ex)), and synchronous-scan excitation spectra of Sep-Pak extractable marine organic matter (SPE-MOM) and its reverse phase HPL C fractions were used to describe the fluorescence characteristics of such naturally occurring organic compounds. Sep-Pak extractable soil f ulvic acid (SPE-SFA) and its chromatographic fractions were used as re ference material. The results show a different distribution of fluores cent material with respect to the chromophoric one in the HPLC fractio ns of SPE-MOM with a higher concentration of the shortest wavelength e mitting fluorophores in the most hydrophobic fraction. No apparent cor relation with polarity was observed for the SPE-SFA sample. Synchronou s-scan excitation spectra indicate a higher presence of the shorter la mbda(ex) fluorophores in SPE-MOM whereas SPE-SFA exhibits a remarkable presence of longer lambda(ex) fluorophores. Hence, a younger formatio n of marine organic matter with a lower structural complexity was post ulated.