摘要
本文研究了Nafion化学修饰钨丝圆盘预富集-石墨炉原子吸收法间接测定头孢拉定的方法,并探讨了测定的机理。在pH为6.9的Cu2+液中,加入的头孢拉定与Cu2+进行配合反应,使原来溶液中的Cu2+量减少,于是交换到Nafion膜上的Cu2+的量也相应减少,从而测得Cu2+的吸光度信号下降。头孢拉定浓度在1.5×10-6-1.0×10-5mol/L范围内,与吸光度下降值呈良好的线性关系,平行测定十次,相对标准偏差为2.0%,最低检出限为1.0×10-6mol/L。同时测得Cu2+与头孢拉定的配合比为1∶2,条件稳定常数为6.9×109。实测药物中头孢拉定的含量,结果令人满意。
A method and its mechaniem for the indirect determination of cephradine by GFAAS after preconentration on Nafion chemically modified tungsten coil are described. In the solution of PH 6.9, cephradine reacts with Cu2+ so that the concentration of Cu2+ in the solution decreases.The amount of Cu2+ exchanged on the Nafion membrane decreases, as a result, the absorption signal of Cu2+ decreases, A linear relation between the decrease of absorbance and concentration of cephradine added is obtained in the range of 1.5 × 10-6-1.0 × 10-5mol / L, The relative standard deviation for ten parallel determinations is 2.0 %. The detection limit by this method is 1.0 × 10-6mol/ L. The complex ratio of Cu2+ and cephradine is 1∶2. The complex stability constant is 6.9 × 109. The results of the content of cephradine in the medicines are satisfactory.
出处
《华东师范大学学报(自然科学版)》
CSCD
1994年第1期56-61,共6页
Journal of East China Normal University(Natural Science)
基金
中科院长春应用化学研究所电分析化学开放实验室资助
关键词
钨丝圆盘
石墨炉
原子吸收法
头孢
Nafion chemically modified tungsten coil GFAAS cephradine