title: Direct determination of polymyxin B sulfate using resonance Rayleigh scattering and resonance non-linear scattering methods with hexatungstate.
abstract: At pH 1.3-1.6, tungstate WO4(2-) , can be converted to hexatungstate W6 O19(2-) , which can react with positively charged polymyxin B sulfate (PMB) to result in enhancement of resonance Rayleigh scattering (RRS) and resonance non-linear scattering, including second order scattering and frequency doubling scattering. Linear relationships can be established between enhanced scattering intensity and PMB concentration. The detection limits (3σ) were 5.5 ng/mL (RRS), 10.1 ng/mL (second order scattering) and 34.6 ng/mL (frequency doubling scattering). The optimum reaction conditions, influencing factors and related analytical properties were tested. The interaction mechanism was investigated via absorption spectrum, circular dichroism spectra and atomic force microscopy imaging. The basis of scattering enhancement is discussed. PMB in eardrops, human serum and urine, were quantified satisfactorily by RRS.
authors.affiliation: School of Chemistry, Chemical Engineering, Key Laboratory of Luminescence, Real-time Analysis of the Ministry of Education, Southwest University, Chongqing, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Kong
authors.forename: Zhongfang
authors.initials: Z
authors.lastname: Liu
authors.forename: Shaopu
authors.initials: S
authors.lastname: Liu
authors.forename: Limin
authors.initials: L
authors.lastname: Wu
authors.forename: Fengling
authors.initials: F
authors.lastname: Tian
mesh_terms: D006801:Humans; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D011112:Polymyxin B / Q000032:analysis* / Q000097:blood / Q000652:urine; D012542:Scattering, Radiation; D017973:Tungsten Compounds / Q000737:chemistry*
chemical_list: D017973:Tungsten Compounds; D011112:Polymyxin B; C045951:tungstate
keywords: hexatungstate; polymyxin B sulfate; resonance Rayleigh scattering; resonance nonlinear scattering