| Resonance Rayleigh scattering (RRS) and resonance non-linear scattering (RNLS) such as second order scattering and frequency doubling scattering etc. is a new technology developed in 1990s. Due to its remarkable characteristics of high sensitivity and simple operation, this method has received much attention. It has been extensively and successfully unitized to study and determination of biological macromolecules, trace metal ions, nonmetal ions and nanoparticle probe et al. Furthermore, it has been applied in pharmaceutical field more and more. However, it is seldom applied to the study of penicillin antibiotics. Therefore, taking the penicillin antibiotics as examples, we have studied and developed the application of the RRS and RNLS methods. In this thesis, we mainly investigated the interaction between penicillin antibiotics and metal ions, oxidants and dyes by the RRS and RNLS methods. Besides, the spectral characteristics, the optimum conditions and the influencing factors were studied. The reaction mechanism was discussed too. Based on the above researches, the RRS and RNLS methods have been established for the determination of penicillin antibiotics. Main investigated systems are listed as follows:1. A Highly Sensitive Resonance Rayleigh Scattering Method for the Determination of Penicillin Antibiotics with Potassium FerricyanideHeated in a boiling water bath, penicillin antibiotics such as amoxicillin, ampicillin, sodium cloxacillin, sodium carbenicillin and sodium benzylpenicillin could react with K3[Fe(CN)6] to form combined products in a dilute HCl medium. As a result, resonance Rayleigh scattering (RRS) intensity was enhanced greatly and new RRS spectra appeared. The maximum scattering wavelengths of the five combined products are all located at 330 nm. The scattered intensity increments (△I) of the combined products are directly proportional to the concentrations of the antibiotics in a certain range. The methods exhibit high sensitivity, and the detection limits for the five penicillin antibiotics are between 4.61 and 5.62 ng·mL-1. The spectral characteristics of RRS and the optimum reaction conditions were investigated. The mechanism of reaction and the reasons for the enhancement of resonance light scattering were discussed. The effects of coexisting substances have been examined, and the results indicated that the method had a good selectivity. It can be applied to the determination of penicillin antibiotics in capsule, tablet, human serum and urine samples.2. Resonance Rayleigh Scattering Spectra of Interaction of Amoxicillin or Ampicillin with Palladium(Ⅱ) and Their Analytical ApplicationsHeated in acidic medium, penicillin antibiotics containing an amino group side chain such as amoxicillin (AMO) and ampicillin (AMP) can be degraded, and the penicillamine and benzyl aminopeniloaldehyde of the degradation products can further react with palladium(Ⅱ) to form a composition ratio 1:1:1 blended ternary complex, which leads to the great enhancement of resonance Rayleigh scattering (RRS) and appearance of new RRS spectra. The spectral characteristics of the reaction products of the two drugs with palladium(Ⅱ) are similar, and the maximum wavelengths are all at 370 run. The scattering intensity increments (△I) of the products are directly proportional to the concentrations of the antibiotics in certain ranges. The method exhibits higher sensitivity, and the detection limits (3σ) for AMO and AMP are 18.0 and 15.4 ng·mL-1, respectively. In this case, the other penicillin antibiotics without any amino group in the structure of the side chain have not similar reactions, and certain amounts of some coexisting substances have no interference. Hence, the method has a good selectivity. It can be applied to the determination of amoxicillin and ampicillin in capsule, tablet, human serum and urine samples with satisfactory results.3. Resonance Rayleigh Scattering, Second Order Scattering and Frequency Doubling Scattering Methods for the Indirect Determination of Penicillin Antibiotics Based on the Formation of Fe3[Fe(CN)6]3 NanoparticlesUnder the condition of HC1 solution and heating, penicillin antibiotics such as amoxicillin (AMO), ampicillin (AMP), sodium cloxacillin (CLO), sodium carbenicillin (CAR) and sodium benzylpenicillin (BEN) can react with Fe(Ⅲ) to produce Fe(Ⅱ) which further reacts with K3Fe(CN)6 to form navy-blue Fe3[Fe(CN)6]2.The hydrophobic Fe3[Fe(CN)6]2 complex will associate to form {Fe3[Fe(CN)6]2}n nanoparticles with an average diameter of 45 nm, which not only result in the change of absorption spectra and appearance of a new absorption peak at 738 nm with the molar absorptivity (ε) of (1.0-2.3)×104 L·mol-1·cm-1 for different antibiotics, but also lead to the significant enhancement of resonance Rayleigh scattering (RRS) and non-linear scattering such as second order scattering (SOS) and frequency doubling scattering (FDS). The RRS, SOS and FDS spectral characteristics of reaction products for five antibiotics were similar, and the maximum scattering wavelengths were 341nm for RRS, 640 nm for SOS and 390 nm for FDS, respectively. But the relative scattering intensities for the investigated drug systems were different. The scattered intensity increments (△I) of five products were directly proportional to the concentrations of antibiotics in certain ranges. The detection limits for five penicillin antibiotics were 2.9-6.1 ng·mL-1 for RRS method, 4.0-6.8 ng·mL-1 for SOS method and 7.4-16.2 ng·mL-1 for FDS method, respectively. Among them, the RRS method exhibited the highest sensitivity. Moreover, the AMO system was more sensitive than other antibiotics systems by three scattering methods. In this work, the reaction conditions of RRS method and the influencing factors were investigated. And taking AMO as an example, the effects of coexisted substances were examined indicating that the method had a good selectivity. Based on the above researches, a highly sensitive, simple and fast method for the indirect determination of penicillin antibiotics has been developed. It was applied in the determination of penicillin antibiotics in capsule, tablet, human serum and urine samples.4. Resonance Rayleigh Scattering, Second Order Scattering and Frequency Doubling Scattering Spectra of Interaction of Amoxicillin with Cerium (Ⅳ) and its Analytical ApplicationIn pH5.0 acetic acid-sodium acetate buffer solution, the interaction of amoxicillin (AMO) with Ce(Ⅳ) can result in the great enhancement of resonance Rayleigh scattering (RRS) and resonance non-linear scattering (RNLS) such as second order scattering (SOS) and frequency doubling scattering (FDS). The new spectra of RRS, SOS and FDS appear and their maximum wavelengths are located at 370, 558, 390 nm, respectively. The scattered intensity increments are directly proportional to the concentration of AMO in a certain range. The methods exhibit high sensitivity, and the detection limits (3o) for the determination of AMO are 2.2 ng·mL-1(RRS method), 3.0 ng·mL-1 (SOS method) and 5.2 ng·mL-1 (FDS method). In this work, the optimum conditions and the influencing factors were investigated. Meanwhile, the effects of coexisting substances have been examined, and the results indicated that the method had a good selectivity. It can be applied to the determination of AMO with Ce(Ⅳ) in capsule, tablet, human serum and urine samples.5. Determination of Penicillin Antibiotics by Resonance Rayleigh Scattering Method with KIO3-KBr- Basic Triphenylmethane DyesIn a weak acid medium, the basic hydrolysis product of penicillin antibiotics (PENs) such as amoxicillin (AMO), ampicillin (AMP), carbenicillin (CAR), sodium cloxacillin (CLO) and sodium benzylpenicillin (BEN) reacts with potassium iodate to form I2 which further interacts with Br- resulting in the formation of [I2Br]- anionic complex. Then an ion-association complex [I2Br][ BTMD] was formed owing to the interaction of [I2Br]- with basic triphenylmethane dyes (BTMD) such as methyl violet (MV), ethyl violet (EV) and crystal violet (CV), which led to the significant enhancement of resonance Rayleigh scattering (RRS) and the appearance of new RRS spectra with their maximum wavelengths near at 330 nm. In certain conditions, the intensities of RRS (△I) are directly proportional to the concentrations of penicillin antibiotics in the range of 0.008-2.0 (MV-PENs system), 0.004-1.0 (EV-PENs system) and 0.008-2.0μg·mL-1 (CV-PENs system). The method exhibits high sensitivity, the detection limits are 2.3-4.4 (MV-PENs system), 1.3-1.7 (MV-PENs system) and 2.4-3.8 ng·mL-1 (MV-PENs system), respectively. In this work, the reaction conditions and the influencing factors have been investigated, and the effects of coexisting substances also have been examined indicating a good selectivity of the method. It can be applied to the determination of penicillin antibiotics in capsule and tablet pharmaceutical formulations and human serum and urine samples.
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