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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。
In this paper, a method for the indirect determination of cefradine by Nafion chemically modified tungsten disk preconcentration-graphite furnace atomic absorption spectrometry was studied, and the mechanism of the determination was discussed. In the Cu2 + solution with pH 6.9, cephradine was added to react with Cu2 + to reduce the amount of Cu2 + in the original solution, and the amount of Cu2 + exchanged to the Nafion membrane was also reduced correspondingly to measure the absorbance signal of Cu2 + decline. Cefradine concentration in the range of 1.5 × 10-6-1.0 × 10-5mol / L showed a good linear relationship with the decrease of absorbance, parallel determination of ten times, the relative standard deviation of 2.0%, the lowest detected The limit is 1.0 × 10 -6 mol / L. At the same time, the ratio of Cu2 + to cephradine was 1: 2 and the stability constant was 6.9 × 109. Measured drug cefradine content, the results are satisfactory.