采用K3[ Fe( CN)6]为探针试剂分光光度法测定卡比马唑的新方法。研究表明,在酸性条件下,卡比马唑使Fe( III)还原为Fe(II),还原生成的Fe(II)可以与K3[Fe(CN)6]反应生成可溶性普鲁士蓝KFeII[FeI(CN)6]。卡比马唑的浓度在0．05~4．8μg/mL范围内与吸光度呈现良好线性关系,线性回归方程A=0．02016+0．35987C(μg/mL),相关系数R=0．9998,检出限为0．042μg/mL,相对标准偏差R． S． D．=0．58%(n=11),间接测定卡比马唑的摩尔吸光系数ε=6．7×105 L/(mol·cm-1)。本方法成功用于药物中卡比马唑含量的测定,平均回收率为98．3%~102．0%,结果满意。%A highly sensitive method for the determination of carbimazole in pharmaceutical preparations was proposed by using potassium ferricyanide as spectroscopic probe reagent. This method was based on the fact that carbimazole can be quantitatively hydrolysed to methimazole, Fe( III) was reduced to Fe( II) by methimazole and the in situ formed Fe( II) reacts with potassium ferricyanide to give soluble prussian blue under pH<4. 0. Beer’s law was obeyed in the concentration range of 0. 05~4. 80 μg/mL of carbimazole with an excellent correlation coefficient ( r=0. 9998 ) . The equation of the linear regression was A=0. 020+0. 35987C (μg/mL) and the detection limit was 0. 042 μg/mL. The apparent molar absorption coefficient of indirect determination of carbimazole was 6. 7 ×104 L/( mol·cm-1 ) . The results showed a sensitive, simple, reliable and readily applied method to determine carbimazole in pharmaceutical product. No interference was observed from common excipients in formulations. Recoveries were within 98. 3% ~102. 0%, with standard deviations ranging from 0. 33% to 0. 85%.
展开▼
