| Diuretic is a potent drug that promotes urine excretion by promoting kidney urinary function. According to the diuretic efficacy we can divide it into three levels: high efficiency, moderate efficiency and low efficiency drugs in clinical. Effective diuretics, is also known as loop diuretics. It was mainly including furosemide, torasemide and Ethacrvnic Acid, etc.. At present furosemide and torasemide used widely in clinical. Whether in efficacy or in the drug applications, have their unique position. Therefore, taking the furosemide and torasemide as examples, we have studied and developed the application of the absorption, fluorescence spectroscopy, resonance Rayleigh scattering and resonance non-linear scattering, second-order scattering, frequency doubling scattering methods. It can be used in the determination of trace drugs in the natural medicine and the pharmaceutical preparation, with satisfactory. Main investigated systems are listed as follow:1. The interaction between furosemide-palladium(II) chelate and basic triphenylmethane dyes by resonance Rayleigh scattering spectra and resonance non-linear scattering spectra and their analytical applicationsIn pH 4.5-7.0 Britton-Robinson buffer solution, Furosemide (FUR) reacted with Pd (II) to form a 1:1 anionic chelate. This chelate could further react with some basic triphenylmethane dyes (BTPMD), such as Ethyl Violet (EV), Crystal Violet (CV), Methyl Violet (MV), Methyl Green (MeG) and Brilliant Green (BG) to form 1:1 ion-association complexes. This not only resulted in the change of absorption spectra, but also led to the significant enhancement of resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS). The maximum RRS wavelengths were located at 324 nm for EV, CV and MV system,340 nm for BG and MeG system; the maximum SOS wavelengths were located at 550 nm for EV, CV, BG and MeG system,530 nm for MV system; The maximum scattering peak of all systems were at 392 nm for FDS. The enhanced RRS, SOS and FDS intensities were directly proportional to the concentration of FUR, respectively. The detection limits for the different dyes systems were 0.3-4.9 ng-mL-1 for the RRS method,3.2-33.1 ng-mL" for the SOS method and 9.0-85.7 ng-mL-1 for the FDS method, respectively. These methods could be used for the determination of trace amounts of FUR. In this work, the effects of the formation of ternary ion-association complexes on the spectral characteristics and intensities of absorption, RRS, SOS and FDS had been investigated. In addition, the optimum conditions of these reactions, the influencing factors and the analytical properties also had been tested. Meanwhile, the influences of coexisting substances were tested by RRS method and the results showed that this method exhibited a high sensitivity. Based on the above mentioned researches, the highly sensitive, simple and rapid methods for the determination of trace amounts of FUR by resonance light scattering technique had been established, which could be satisfactorily applied to the determination of FUR in tablet, injection, human serum and urine samples. Moreover, the composition and structure of the ternary ion-association complex and the reaction mechanism were also discussed in this work.2. Resonance Rayleigh scattering, Second-Order Scattering and Frequency Doubling Scattering Spectra of Interaction of Furosemide with Ag (I) and Their Analytical ApplicationsIn pH 3.5 HAc-NaAc buffer solution, furosemide reacted with Ag (I) to form a 1:1 chelate. In this case, the intensities of resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS) spectra were enhanced greatly and the new scattering spectra appeared. The maximum RRS, SOS and FDS wavelength was located at 310,584,330 nm, respectively. The intensities of RRS, SOS and FDS were directly proportional to the concentration of furosemide in a certain range and the detection limit was 1.3 ng-mL-1,3.0 ng-mL"1 and 6.9 ng-mL-1, respectively. In addition, the optimum conditions and the influences of coexisting substances were tested by RRS method and the results showed that this method had good selectivity. Therefore, a new simple, rapid, and sensitive light scattering method has been developed for the determination of furosemide in tablets and urine samples. In addition, the reaction mechanism and the reasons for the enhancement of scattering spectra were discussed.3. Resonance Rayleigh Scattering and Resonance Nonlinear Scattering spectra of Pd(II)-Torasemide System and Its Analytical ApplicationIn a Britton-Robinson buffer solution of pH 4.0-7.0, torasemide(TOR) reacts with Pd (II) to form a 1:1 chelate, which results in the intensities of resonance Rayleigh scattering (RRS), second-order scattering (SOS) and frequency doubling scattering (FDS) are greatly enhanced. The maximum RRS, SOS, FDS wavelength are located at 340,586,349 nm, respectively. The enhanced RRS, SOS and FDS intensities are directly proportional to the concentration of torasemide in a certain range. The methods also have high sensitivities and the detection limits for TOR are between 1.1 ng-mL-and 5.5 ng-mL"1. The optimum conditions and the effects of coexisting substances are investigated and the results show that the methods exhibit a good selectivity. Based on the above researches, a highly sensitive, simple and quick method for the determination of torasemide has been developed.4. Study on the interaction between torasemide and 12-tungstophosphoric acid by resonance Rayleigh scattering and resonance nonlinear scattering spectra and its analytical applicationsIn 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.5. Study on the interaction between torasemide and bovine serum albumin by fluorescence spectroscopy and its analytical applicationUnder the simulation physiological conditions (at pH7.40 and 0.15 mol·L-1 ionic strength), the intrinsic fluorescence of bovine serum albumin (BSA) was quenched by TOR. From the change of absorption spectrum, the effect of temperature and the quenching constant, this procedure was judged to be static quenching process on account of the TOR interacting with BSA to form ground state coordination compounds. In this paper, the binding constants (K), the binding sites (n) and the thermodynamic properties between TOR and BSA had been calculated. The results shows that the TOR can quench the fluorescence of BSA and the mechanism is static quenching process. The fluorescence of BSA was quenched regularly by the TOR in certain ranges. And at the maximum quenching wavelength 342 nm, the value of the fluorescence quenching (△F) was directly proportional to the concentration of TOR in the range of 0.02～5.0μg·mL-1 and the detection limit was 6.3 ng-mL-1. In the work, the optimum conditions and the influencing factors were investigated. The results showed that this method exhibited a high sensitivity and selectivity. Based on this, a novel fluorescence quenching method for the determination of trace TOR with BSA as a fluorescence probe has been developed. It has been applied to the determinstion of TOR in tablets and urine samples with satisfacory results.
|
PDF Full Text Request