[Complexing mechanism on extraction of DHA ester using silver ion].

Ultraviolet spectra of docosahexaenoic acid (DHA) ester and its complex with silver ion were determined, and shifts of ultraviolet absorption peak before and after the complexing reaction were observed. Meanwhile, complexing bonds of DHA ester-silver ion were explained by molecular orbital theory. Thus, complex structure and complexing mechanism were discovered. The results showed that ultraviolet characteristic absorption peak of DHA ester-silver ion complex moved to lower wavelength. It pointed out that distance between energy levels for outer electron transition of complex is increased, and the energy for outer electron transition of complex is bigger than that of DHA ester.