Abstract: In the solution of 0.4KOH+0.6mol NH₄Cl+0.1Im. mol/L (pH=9.5), the irradiation of UV-Vis light has great effects on the formation of ZnTPPS. The experimental results of photopolarography have shown that the relationship between photocurrent (i_p) and concentration (C) are: i_p∝C_Zn^1/2(NH₃)₄²⁺ for Zn(NH₃)₄²⁺and i_p∝C_H2TPPS for the third reduetive wave (P₃)of H₂TPPS, respectively, while the first reductive wave (P₁) of H₂TPPS and the wave P_c of ZnTPPS do not produce photocurrent. The differences in photoeurrents were discussed briefly.

Key words: H₂TPPS, ZnTPPS, photopolarography