差分光谱法原位检测质子化作用过程

差分光谱法原位检测质子化作用过程InSituExaminationoftheProtonationBehaviorofFulvicAcidsUsingDifferentialAbsorbanceSpectroscopyDEBORAHJ.DRYER,†GREGORYV.KORSHIN,*,†ANDMASSIMILIANOFABBRICINO‡DepartmentofCivilandEnvironmentalEngineering,UniversityofWashington,Seattle,Washington98195-2700UnitedStates,korshin@u.washington.edu,andDipartimentodiIngegneriaIdraulicaedAmbientale”GirolamoIppolito”,Universit´adegliStudidiNapoliFedericoIIViaClaudio21,80125NaplesItalyReceivedMarch14,2008.RevisedmanuscriptreceivedJune23,2008.AcceptedJune30,2008.TheeffectsofpHchangesontheabsorbancespectraoffulvicacids,whichconstituteamajorpartofnaturalorganicmatter(NOM)wereexaminedbasedprimarilyontheexampleofstandardSuwanneeRiverfulvicacid(SRFA).DifferentialabsorbancespectraofSRFAgeneratedatvaryingpHvaluesweredeterminedtoberichinfeaturesthatareabsentintheconventionalspectra.AnalysisofthedifferentialabsorbancerevealedtheexistenceoftwopredominanttypesofpH-activechromophoreswhichproducedfeaturesthatemergedinthepHrangesassociatedwithcarbox