简介：Anovelpentaazadentatebismacrocydewassynthesizedthroughanimprovedprocedureof1:1Schiffbasecondensationofdiformyltripyrranewith3,4,3’,4’-tetraamino-biphenylhydrochlorideusingPh2+astemplateion,inwhichthecondensedbyproductwaterwasremovedefficientlytomaketheyieldover90%.Thenthebismacrocyclicligandreactedwithcadmiumchloridetoyieldthetitlemetalcomplexwithmolecularweightbeing1200.4byTOFMSandtheλmaxbeing766nm.

简介：Co-contaminationofatrazine(AT)andcadmium(Cd)onthesurficialsediments(SSs)andnaturalsufacecoatingsamples(NSCSs)wasinvestigatedviathermodynamicadsorptionexperiments.TheresultsshowthatsurfacecoatingshaveastrongerabilitytoadsorbATowingtotheirhigheractivecomponentscomparedwithsurficialsediments.SynergeticandantagonisticeffectsofCdontheadsorptionofATwereobserved.Cdatalowerconcentra-tion(≤4.0mg/L)inthesolid/liquidphaseenhancedATadsorptionontothesurficialsediments(surfacecoatings),whiletheadsorptionofATwouldbeinhibitedataCdconcentrationofmorethan8.0mg/L:ATcoordinatesstronglytoCd,andAT-CdcomplexesseemtobemorestronglyadsorbedonsedimentsthanATalone,andattheadsorptionofATcantakeplaceonthesiteswhereCdhasbeenpreviouslyadsorbedandCdactsasabridgefortheinteractionbetweensedimentsandAT.WiththeincreaseofCdconcentration,thesuperfluousCdmayholdmuchmoreadsorptionsitesandthusinhibitstheadsorptionofAT.Meanwhile,theeffectsofco-existedATonCdadsorptiononSSs(NSCSs)wereinsignificantsinceCdhasastrongercompetitiveabilitytobeabsorbedonSSs(NSCSs).Thepresentstudycouldbeusefulinpredictinginteractionsofthemetalionswithherbicidesandpotentiallyaidthedesignofremediationstrategiesforcontaminatedsedimentsandgroundwater.

简介：Anovelthird-generationhydrogenperoxide(H_2O_2)biosensor(Hb/CdS/MWNTs/GCE)wasfabricatedthroughhemoglobin(Hb)adsorbedontothemercaptoaceticacidmodifiedCdSQDs/carboxylmultiwallcarbonnanotubes'(MWNTs)films.CyclicvoltammogramofHb/CdS/MWNTs/GCEshowedapairofwell-definedandquasi-reversibleredoxpeakswithaformalpotential(E~0)of-0.230V(vs.Ag/AgCl)in0.1mol/LpH=8.0phosphatebuffersolution(PBS),whichwasthecharacteristicoftheHbhemeFe(Ⅲ)/Fe(Ⅱ)redoxcouple.ThebiosensorshowsanexcellentelectrocatalyticactivitytothereductionofH_2O_2.TheresponsetimeofthedesignedbiosensortoH_2O_2atapotentialof-0.30Vwaslessthan2sandlinearrelationshipswereobtainedintheconcentrationrangesof2.0×10~(-6)—2.7×10~(-3)mol/Land2.7×10~(-3)—7.7×10~(-3)mol/Lwithadetectionlimitof3.0×10~(-7)mol/L(S/N=3).TheapparentMichaelis-MentenconstantK_mwasestimatedtobe1.324mmol/LthatillustratedtheexcellentbiologicalactivityofthefixedHb.

简介：Naturalsurfacecoatingscollectedfromnaturalsubstances(NSCsNS)wereemployedtostudytherolesofthemainchemicalcomponents(ironoxides,manganeseoxides,andothercomponents)incontrollingtheadsorptionoflead(Pb)andcadmium(Cd)inaquaticenvironments.TheselectivechemicalextractionfollowedbytheadsorptionofPbandCdexperimentsandstatisticalanalysis,wereusedtoinvestigatetheadsorptionpropertyofeachcomponent.Hydroxylaminehydrochloridewasusedtoremovemanganeseoxidesselectively,andsodiumdithionitewasusedtoextractironoxidesandmanganeseoxides.TheresultindicatedthatironoxidesandmanganeseoxidesplayedanimportantroleintheadsorptionofPbandCdonNSCsNS,andtherelativecontributionwasabouttwo-thirds.Thecontributionofmanganeseoxideswasthegreatest,withalesserroleindicatedforothercomponents.TheadsorptionabilityofmanganeseoxidesforPbandCdwasgreaterthanthatofironoxidesorothercomponentsforPbandCd.ThePbadsorptionobservedineachcomponentwasgreaterthanCdadsorption.