title: Study on the interaction between torasemide and 12-tungstophosphoric acid by resonance Rayleigh scattering and resonance nonlinear scattering spectra and its analytical applications.
abstract: In pH 0.6-1.1 HCl-NaAc buffer solution, torasemide (TOR) reacted with TP to form a 3:1 ion-association complexes. As a result, not only the absorption spectra were changed, but also the intensities of resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS) were enhanced greatly. The maximum RRS, SOS and FDS wavelengths were located at 370, 333, 776 nm, respectively. Under given conditions, the intensities of RRS, SOS and FDS were all directly proportional to the concentration of TOR. The detection limits of RRS, SOS and FDS were 0.7173 ng mL(-1), 7.007 ng mL(-1) and 10.90 ng mL(-1). The optimum conditions and the effects of coexisting substances on the reaction were investigated. The results showed that the method had good selectivity. Therefore, a highly sensitive, simple and quick method has been developed for the determination of TOR. The method can be applied satisfactorily to the determination of TOR in tablets and urine samples.
authors.affiliation: School of Chemistry and Chemical Engineering, Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, Southwest University, Chongqing 400715, PR China.
authors.forename: Cuixia
authors.initials: C
authors.lastname: Li
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Hu
authors.forename: Shaopu
authors.initials: S
authors.lastname: Liu
authors.forename: Zhongfang
authors.initials: Z
authors.lastname: Liu
mesh_terms: D006801:Humans; D009994:Osmolar Concentration; D010756:Phosphoric Acids / Q000737:chemistry*; D012542:Scattering, Radiation; D013449:Sulfonamides / Q000032:analysis* / Q000378:metabolism* / Q000652:urine; D013607:Tablets / Q000032:analysis* / Q000737:chemistry; D000077786:Torsemide; D017973:Tungsten Compounds / Q000737:chemistry*; D014732:Vibration
chemical_list: C519880:12-tungstophosphoric acid; D010756:Phosphoric Acids; D013449:Sulfonamides; D013607:Tablets; D017973:Tungsten Compounds; D000077786:Torsemide