摘要
目的：研究醋酸甲羟孕酮（ＭＰＡ）的电极反应机理，拟定了测定ＭＰＡ的单扫描示波极谱法。方法：用单扫描示波极谱法、快速扫描循环伏安法、恒电位电解法、紫外分光光度法等多种技术进行研究。结果：在醋酸盐缓冲溶液中，ＭＰＡ的Ｃ＝Ｃ双键首先发生单电子单质子还原，产生了中间体自由基ＨＭＰＡ·。随后ＨＭＰＡ·可以单电子单质子方式进一步还原，形成产物Ｈ２ＭＰＡ；同时也可以与中性ＭＰＡ分子形成二聚体自由基ＨＭＰＡ·ＭＰＡ·。在０２ｍｏｌ·Ｌ－１ＨＡｃ—ＮａＡｃ缓冲液中，ＭＰＡ还原波的二阶导数峰电流ｉＰ″与其浓度ＣＭＰＡ在２０×１０－６～６０×１０－５ｍｏｌ·Ｌ－１范围内成线性关系，相关系数γ＝０９９８。结论：证实ＭＰＡ的还原过程有中间体自由基参与。
AIM: To study the polarographic behaviour and reduction mechanism of medroxyprogesterone acetate (MPA) in acetate buffer solution. A new method for the determination of MPA was established by linear sweep polarography. METHODS: Fast scan cyclic voltammetry, controlled potential electrolysis, linear sweep polarography and ultraviolet visible spectrophotometry were used in the present research. RESULTS: The C=C bond of MPA first undergoes a 1 e, 1H + reduction to form a radical HMPA ·, then the further reduction of HMPA · in 1 e, 1H + process is simultaneous with the dimerization reaction between HMPA · and the neutral molecule MPA. In 0 2 mol·L -1 HAc NaAc (pH 5 0) buffer solution, the reduction wave ( E P= -1 33 V , vs.SCE) of MPA can be used for analytical purpose. The second order derivative peak current of MPA is linear with the MPA concentration over the range of 2 0×10 -6 ～6 0×10 -5 mol·L -1 . The linear regression equation is i P″(nA)=5 81+6 8×10 5 C MPA (mol·L -1 ), and the correlation coefficient γ=0 998. The detection limit is 8 0×10 -7 mol·L -1 .CONCLUSION: The characteristics of the polarographic reduction of steroids was elucidated. The process of reduction was the two step transmission process of electric charge with the intermediate free radical.
出处
《药学学报》
CAS
CSCD
北大核心
1999年第7期530-534,共5页
Acta Pharmaceutica Sinica
基金
国家自然科学基金
关键词
醋酸甲羟孕酮
单扫描
示波极谱法
medroxyprogesterone acetate
steroid
linear sweep polarography
