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在水和DMF两种介质中 ,研究了醋酸甲羟孕酮 (MPA)的极谱行为和极谱催化波机理 .结果表明 ,在 0 .2mol/LHAc_NaAc (pH =5 .0 )缓冲水溶液中 ,MPA的CC双键首先经单电子单质子还原产生质子化的中间体自由基HMPA·;HMPA·继续以单电子单质子方式进一步还原 ,同时伴随有HMPA·与中性MPA分子生成二聚体自由基HMPA·MPA·的化学反应 .在 0 .1mol/LTBA·BF4的DMF溶液中 ,MPA的CC双键还原是连续的 2步单电子还原 ,2步分别为MPA和中间体自由基MPA· -的还原 ,没有二聚化反应发生 .上述过程产生的均是MPA的还原波 .在氧化剂KIO3 存在下 ,MPA还原的中间体自由基HMPA·或MPA· -被KIO3 及其中间氧化态质点化学氧化再生MPA ,产生了极谱催化波 .这种由有机化合物在电极上自身还原、通过化学反应氧化有机中间体自由基再生原有机化合物的催化波是一种新型极谱催化波 .在上述条件下 ,MPA催化波的灵敏度比其还原波高一个数量级 ,可用于分析目的 .求得催化反应的表观速率常数Kf=1 .7× 1 0 3 mol·L-1·s-1.
The polarographic behavior and polarographic catalytic wave mechanism of medroxyprogesterone acetate (MPA) were studied in water and DMF.The results showed that in the buffer solution of 0.2 mol / L HAc_NaAc (pH = 5.0) The CC double bond of MPA first undergoes a single electron proton reduction to produce the protonated intermediate radical HMPA ·; HMPA · continues to be further reduced by the mono-electron uni-proton mode accompanied by HMPA · dimer formation with neutral MPA molecules Chemical reaction of HMPA · MPA · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·. , And no dimerization occurred.The above process all produced the reduction wave of MPA.At the presence of oxidant KIO3, MPA reduced intermediate HMPA · or MPA · was chemically oxidized by KIO3 and its intermediate oxidation state Regeneration of MPA, resulting in the polarographic catalytic wave of organic compounds in the electrode self-reduction by chemical reaction oxidation of organic intermediates free radical regeneration of the original organic compounds catalytic wave is a new polarographic catalytic wave. Under the above conditions , MPA catalytic wave sensitivity ratio An order of magnitude reduction wave, can be used for analytical purposes. Calculated apparent rate constant of the reaction catalyzed Kf = 1 .7 × 1 0 3 mol·L-1 · s-1.