硼酸催化茚三酮与盐酸肼屈嗪的反应及分析应用

Boric Acid Catalyzed Ninhydrin-Hydralazine Hydrochloride Reaction and Its Application to Analysis of Hydralazine Hydrochloride

肼的衍生物和茚三酮发生反应,生成一种含有—NHN=CH-基团的化合物——腙,该反应在常温下缓慢进行.研究发现,在pH=6.2的PB缓冲条件下,硼酸可以显著地加快该反应的速度,将该反应用于盐酸肼屈嗪的快速测定,其浓度在0.5～40μmol/L范围内,与反应产物在436nm处的吸光度变化值呈良好的线性关系(r=0.9994),检出限为0.18μmol/L.研究了适宜的反应条件,初步探讨其反应机理.

Hydrazine derivatives can react with ninhydrin to generate a colorful product containing-NHN =CH-groups-hydrazone. The reaction is slow at room temperature. It was found in this study that in pH 6.2 PB buffer the above reaction was accelerated if boric acid catalyzed it. Then this finding was applied in rapid determination of hydralazine. Under the optimum reaction conditions, the increment of absorbance （436nm） was directly proportional to the concentration of hydralazine hydrochloride in the ranges of 0.5- 40 μmol/L（r=0. 9994）, with a detection limit of 0.18 μmol/L. Furthermore, the reaction mechanism is discussed based on the boric acid-catalyzed reaction.