稀土四环素络合物曾用于检查脑癌。国内曾用三价铈四环素络合物作抗癌临床试验。本文找到三氯化铈和四环素的水溶液浓度各为1×10~(-4)M,离子强度为0.01M,温度为25℃±0.5时,二者的混合液不出沉淀。在以上条件下用电位滴定法测定了四环素的加质子常数(K_1~H,K_2~H,K_3~H,K_4~H)和三价铈四环素络合物的稳定常数(βceHL,βceH_2L,βceH_3L)。此外,还制备了固态三价铈四环素络合物,并作了红外光谱分析。 Rare earth tetracycline complex was used to check brain cancer. Trivalent cerium tetracycline complexes have been used as anti-cancer clinical trials. In this paper, the concentration of cerium trichloride and tetracycline in aqueous solution is 1 × 10 ~ (-4) M, the ionic strength is 0.01M and the temperature is 25 ℃ ± 0.5. The stability constants (βceHL, βceH_2L, βceH_3L and βceH_2L) of tetracycline were determined by potentiometric titration under the above conditions with addition of proton constants (K_1H, K_2H, K_3H, K_4H) ). In addition, a solid trivalent cerium tetracycline complex was prepared and analyzed by infrared spectroscopy.