分光光度法测定大豆苷的研究

Study on Determination of Daidzin Using Spectrophotometry

在pH6 5的Na2 HPO4 -NaH2 PO4 缓冲溶液中 ,Fe(Ⅲ ) -BPR及Al(Ⅲ ) -BPR与大豆苷形成有色络合物 ,络合物的最大吸收波长分别为 5 5 0nm和 5 80nm ,摩尔吸收系数分别为 5 88× 10 2 和 3 71×10 2 m2 ·mol- 1(摩尔吸光系数分别为 5 88× 10 3和 3 71× 10 3L·mol- 1·cm- 1) .在pH10 5的NH3-NH4 Cl缓冲介质 ,孔雀绿 ,罗丹明B ,结晶紫 ,甲基紫和乙基罗丹明B均可与大豆苷缔合显色 ,但灵敏度以后者为最高 ,摩尔吸收系数达 1 74× 10 3m2 ·mol- 1(摩尔吸光系数 1 74× 10 4 L·mol- 1·cm- 1) .本文还探讨了在实验条件下 。

In pH6 5 phosphate buffer solution,daidzin(DN)reacts with Fe(Ⅲ) BPR and Al(Ⅲ) BPR to form color complexes.The maximum absorption of the complexes is 550 nm or 580 nm with the molar absorptivity of 5.88×10 3 and 3.71×10 3 L·mol -1 ·cm -1 respectively.In pH10 5 NH 3 NH 4Cl buffer solution,DN reacts to form color association complexes respectively with malachite green ,rhodamine B.crystal violet,methyl violet and ethylrhodamine B.The complex from DN reacting with ethylrhodamine B is most sensitive with the molar absorptivity of 17.4×10 3 L·mol -1 ·cm -1 .The mechanisms of the color reaction of DN with different reagents are discussed.