物理化学学报 >> 1986, Vol. 2 >> Issue (06): 549-553.doi: 10.3866/PKU.WHXB19860611

研究论文 上一篇    下一篇

胭脂红酸极谱行为的研究

李南强; 闵静   

  1. 北京大学化学系
  • 收稿日期:1985-10-17 修回日期:1986-04-04 发布日期:1986-12-15

A POLAROGRAPHIC STUDY OF CARMINIC ACID

Li Nanqiang; Min Jing   

  1. Department of Chemistry; Peking University; Beijing
  • Received:1985-10-17 Revised:1986-04-04 Published:1986-12-15

摘要: 在醋酸盐缓冲溶液中, 可获得胭脂红酸的单扫可逆吸附波。在pH4.3时, E_p=一0.65 V(vs. S.C.E.), 电极反应是由醌型还原为氢醌型。胭脂红酸在汞电极上的吸附符合Frumkin等温武。测得吸附系数β=7.0×10~6, 作用因素v=-0.92, 吸附速率常数k_(ads)=9.7×10~(-8) cms~(-1)。

Abstract: In 0.2 mol L~(-1)acetate buffer Solution, at pH 4.2—4.5, carminic acid exhibits a reversible adsorptive wave in single-sweep polarogram. The electrode reaction is
(H_2L~(-))_(ads)+2H~++2e<=>(H_2L′~-)_(ads)
H_2L~- and H_2L′~(-) are the anthraqluinone and dihydroanthraquinone ions of carminic acid respectively.
On the surface of mercury electrode,the adsorption of carminic acid obeys Frumkin adsorption isotherm The adsorption coefficient(β=7.0×10~6), the interaction factor(v=-0.92), the amount of saturated adsorption (Γ_s=1.39×10~(-10) mol cm~(-2) and t...