[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.