在pH 7.84的NaH2PO4-Na2HPO4缓冲介质中,百里酚蓝与阿昔洛韦反应形成离子缔合物,最大吸收波长为596 nm,并在436 nm波长处产生负吸收.阿昔洛韦的浓度在2.05×10-6~2.38×10-5mol·L-1内遵守比耳定律,ε=3.19×104L·mol-1·cm-1,检出限为6.21×10-7mol·L-1.若用双波长叠加,ε=4.46×104L·mol-1·cm-1,检出限为5.13×10-7mol·L-1.用于药品、血浆及尿液中阿昔洛韦的测定,RSD为0.68%~2.76%,回收率为99.1%~103.3%.对反应机理进行探讨,表明离子缔合物的形成不仅由静电引力引起,且与荷移作用和范德华力有关.

In a phosphate buffer medium of pH 7.84,an ion association complex was formed between aciclovir (ACV) and thymol blue (TMB) with its positive absorption maxima at 596 nm,and negative absorption maxima at 436 nm.Linear relationships were obtained at both absorption maxima,and Beer′s law was held in the range of 2.05×10-6 to 2.38×10-5mol·L-1 of ACV at 596 nm,with an apparent molar absorptivity (ε596) of 3.19×104L·mol-1·cm-1,and a detective limit of 6.21×10-7mol·L-1.By applying the dual-wavelength measurement with wavelength addition method,the molar absorptivity was increased to 4.46×104L·mol-1·cm-1 and a lower detection limit of 5.13×10-7mol·L-1 was obtained.Most of the commonly coexisting ions and substances were found not interfering.In the analysis of some a ciclovir drugs,and the RSD′s (n=6) calculated were in the range of 0.68%-2.76%.Results of recovery test obtained were in the range of 99.1%-103.3%.Reaction mechanism of the formation of ion association complex between ACV and TMB was studied and it was shown that the ion-association complex was formed not only due to electrostatic action,but also to charge transferring and to the van der waals force and the hydrophobic action.