摘要
Twenty-threeprogressiveextractionswereperformedtostudyindividualhumicacids(Has)andhuminfractionsfromatypicalblacksoil(Mollisol)inHeilongjiangProvince,Chinausingelementalanalysisandspectroscopictechniques.After23HAextractionstheresiduewasseparatedintohighandloworganiccarbonhuminfractions.HAyieldwasthehighestforthefirstextractionandthengraduallydecreasedwithfurtherextractions.Organiccarbon(OC)ofthehuminfractionsaccountedfor58％oftotalOCevenafter23successiveHAextractions.Inaddition,theatomicC/HratiodecreasedduringthecourseofextractionwhileC/Oincreased;theE4/E6ratiofromtheUVanalysisdecreasedwithfurtherextractionwhileE2/Eaincreased;thebandassignedtoaliphaticcarbon(2930cm-1)inthediffusereflectanceinfraredFouriertransformspectroscopy(DRIFTS)spectragraduallyincreasedwithprogressiveextraction;thecalculatedratioofthesumofaromaticcarbonpeakheightstothatofaliphaticcarbonpeakheightsfromDRIFTSspectradeclinedwithextractions;andnuclearmagneticresonance(NMR)datasuggestedthatHAaliphaticcarbonsincreasedwithextractionswhilearomaticcarbonsdecreased.Thus,hydrophobicityandaliphaticityofHasincreasedwithextractionswhilepolarityandaromaticitydecreased.Thesedatashowedsubstantialchemical,structural,andmoleculardifferencesamongthe23Hasandtwohuminfractions.Therefore,theseresultsmayhelpexplainwhysoilandsedimenthuminfractionshavehighsorptioncapacityfororganiccontaminants.
出版日期
2005年01月11日（中国期刊网平台首次上网日期，不代表论文的发表时间）
