【摘要】 利用吸收光谱、荧光猝灭法、圆二色谱法及芘荧光探针法,探讨了环糊精(CDs)对腐植酸(HA)与以芘为代表的多环芳烃(PAHs)相互作用的影响.β-CD与HA的吸收光谱和荧光光谱测定结果表明:β-CD能够包络HA的芳环部分;荧光猝灭法和圆二色谱法测定结果表明:HA能够与被β-CD空腔包络的芘分子发生相互作用,CDs和HA之间存在与芘相互作用的竞争;用荧光猝灭法测定了四种不同CDs存在下HA和芘的结合常数,并用芘为荧光探针进行测定,结果表明:CDs浓度较低时,HA对芘的作用占优势;反之,CDs占优势.与其它三种CDs不同,γ-CD存在下HA与芘的结合常数随其浓度的升高一直增大.更多还原

【Abstract】 The effects of cyclodextrins(CDs)on the interaction between humic acid(HA) and polycyclic aromatic hydrocarbons(PAHs) by absorption spectrometry,fluorimetry,circular dichroism spectroscopy(CDs),and fluorescent probe method were investigated.The absorption spectra and fluorescence spectra of HA in the present of β-CD indicated that HA can be interacted with pyrene which has been included in the cavity of β-CD.These interactions were competitive between CDs and HA depended on their concentrations respectively.The binding constant(KOC) between HA and pyrene in the present of four kinds of CDs,such as α-CD,γ-CD,DMCD and HPCD were also investigated by fluorescence quenching method.It was revealed that HA played a dominative role in the interaction with pyrene when concentration of CDs was low.Contrarily,CDs was in the ascendant when its concentration was high.KOC of HA and pyrene in the presence of γ-CD increased with the increment of its concentration all along.The value of I1/I3 of pyrene,as a fluorescent probe method,was also investigated to support the mentioned result.更多还原