阻抑速差催化光度法测定磺胺类药物

Determination of sulfa drugs by inhibitory-catalytic spectrophotometry

研究了磺胺嘧啶（SD），磺胺二甲嘧啶（SM2），抑制了碘催化As（Ⅲ）-Ce^4＋反应速率的条件，建立了阻抑速差光度法测定磺胺类药物的新方法。结果表明，在含0．01mg／L I^-，0．225mol／L H2SO4，0．5g／L NaCl，0．00125mol／L As2O3和0．00lmol／L Ce^4＋溶液中测定SD和SM2的线性范围分别为2．25～3．75和2．0～3．5mg／L；检出限为2．1×10^-4和2．7×10^-4g／L；表观摩尔吸光系数（L·mol^-1·cm^-1）为3．44×10^4和2．76×10^4。已用本法测定SD和SM2针剂和SM2片剂。

A method for the determination of sulfa drugs by inhibitory catalytic spectrophotometry is proposed based on inhibiting effect of sulfadiazine and sulfamethazie on oxidation of arsenous acid with sulfate cerium （ Ⅳ ） catalyzed by iodide anion. The linear ranges of the determination are 2.25 ～ 3.75 and 2.0 ～ 3.5 mg/L, the detection limit is 2.1 × 10^-4 and 2.7 × 10^-4 g/L, the apparent molar absorptivities are 3.44 × 10^4 L·mol^-1·cm^-1 and 2.76 × 10^4 L·mol^-1·cm^-1. This method has been applied to the determination of the sulphonamides with satisfactory results.