[Measurement and analysis of nanometer particles of silica and carbon black by diffuse reflection FTIR spectra].

By using FTIR-FTS3000 spectrometer and infrared diffuse reflection accessory, the spectra of the nanometer particles of silica, carbon black and their blends with different weight ratio were collected and characterized. It was found from the measured results that blue-shift and broadening phenomenon occurred in the nanometer particle materials in comparison with the mass ones. These phenomena could be explained by the little size effect and quantum size effect. No perfect spectrum could be collected because of the strong absorbance of the nanometer particle materials. For the blends of silica and carbon black there was a maximum absorption corresponding to the critical concentration, where the weight ratio of silica to carbon black was 100 : 20, and below this ratio the relationship between the function F(R) and the concentration obeyed Lambert-Beer's law. Above this ratio, the absorbance will not increase with increasing the proportion of the carbon black in the system.

[Time resolved UV-Vis absorption spectra in synthetic process of quercetin complex with Al3+].

With a deuterium light source was used to provide the continuous light, the time resolved UV-Vis absorption spectra in the synthetic process of quercetin complex with Al3+ were measured by using an intensified ICCD spectroscopic detector. The measuing system was controlled synchronously by using a digital delay generator DG535. A total of 50 spectra with the exposure time of 1 micros for each spectrum and the time interval of 20 ms between two successional spectra were acquired. Results showed clearly that the typical bands centered at 254 and 374 nm of quercetin disappeared at 40 ms after the reaction started; at the same time, an absorption band centered at 384 nm of a transitional product appeared, and the typical absorption band centered at 300 nm of Al3+ still existed; with the reaction progressing, the bands of the transitional product and Al3+ disappeared, and the new bands centered at 267 and 436 nm of the complex of quercetin with Al3+ appeared and became stronger gradually; at 980 ms, the typical absorption band of Al3+ disappeared completely and the two typical absorption bands of the complex increased to the strongest. The synthetic reaction of quercetin complex with Al3+ finished within one second. The process of Al3+ being scavenged is shown in the spectra obviously. The prensent results provide experimental evidence for the Al3+ scavenging ability of quercetin.

[The measurement and analysis of visible-absorption spectrum and fluorescence spectrum of lycopene].

Using ICCD spectral detection system, the absorbency of lycopene-carbon bisulfide solution with different concentration was measured, and the result shows that in a specified range the absorption rule of lycopene solution agrees with Lambert-Beer Law. Absorption spectral wavelength shifts were measured respectively when lycopene was dissolved in acetone, normal hexane, petroleum ether, benzene, ethyl acetate, and carbon bisulfide, and comparing to acetone, different red-shift appeared when lycopene was dissolved in benzene, ethyl acetate, and carbon bisulfide when water was added in lycopene-acetone solution, t he absorbency of lycopene dropped, the fine structure of absorption spectrum became indistinct, and a new absorption peak appeared in UV. The reason for these phenomena is that the solvent molecule had different effect on lycopene molecule when lycopene was dissolved in different solvent. Using fluorecence spectrophotometer, fluorescence spectra of lycopene in different concentrations were collected, and the results show that the fluorescence spectra of lycopene were mainly in 500-680 nm. When concentration was lower than 50 microg x mL(-1), the fluorescence intensity linearly increased with increasing concentration, and when concentration was higher than 60 microg x mL(-1), the fluorescence intensity dropped because of the interaction between lycopene molecules.