title: A rapid and sensitive resonance Rayleigh scattering spectra method for the determination of quinolones in human urine and pharmaceutical preparation.
abstract: A new method based on resonance Rayleigh scattering (RRS) was proposed for the determination of quinolones (QNS) at the nanogram level. In pH 3.3-4.4 Britton-Robinson buffer medium, quinolones such as ciprofloxacin, pipemidic acid (PIP), lomefloxacin (LOM), norfloxacin (NOR) and sarafloxacin (SAR) were protonated and reacted with methyl orange (MO) to form an ion-pair complex, which then further formed a six-membered ring chelate with Pd(II). As a result, new RRS spectra appeared and the RRS intensities were enhanced greatly. RRS spectral characteristics of the MO-QNS-Pd(II) systems, the optimum conditions for the reaction, and the influencing factors were investigated. Under optimum conditions, the scattering intensity (∆I) increments were directly proportional to the concentration of QNS with in certain ranges. The method had high sensitivity, and the detection limits (3σ) ranged from 6.8 to 12.6 ng/mL. The proposed method had been successfully applied for the determination of QNS in pharmaceutical formulations and human urine samples. In addition, the mechanism of the reaction system was discussed based on IR, absorption and fluorescence spectral studies. The reasons for the enhancement of scattering spectra were discussed in terms of fluorescence-scattering resonance energy transfer, hydrophobicity and molecular size.
authors: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), Ministry of Education, College of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
authors: Man
authors: M
authors: Qiao
authors: Yaqiong
authors: Y
authors: Wang
authors: Shaopu
authors: S
authors: Liu
authors: Zhongfang
authors: Z
authors: Liu
authors: Jidong
authors: J
authors: Yang
authors: Jinghui
authors: J
authors: Zhu
authors: Xiaoli
authors: X
authors: Hu
mesh_terms: D002626:Chemistry, Pharmaceutical; D064368:Healthy Volunteers; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D004364:Pharmaceutical Preparations / Q000737:chemistry*; D015363:Quinolones / Q000032:analysis* / Q000652:urine*; D012542:Scattering, Radiation; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013997:Time Factors
chemical_list: D004364:Pharmaceutical Preparations; D015363:Quinolones
keywords: Pd(II); methyl orange; quinolones; resonance Rayleigh scattering