将间接电合成苯甲醛与电还原马来酸制备丁二酸的过程有机结合,构建了一个新的成对电解体系,即在隔膜电解槽中,以纯Pb为阴极,PbO2/Pb为阳极,硫酸溶液为介质,在施加超声波的条件下,阳极氧化Ce3+为Ce4+,阴极还原马来酸生成丁二酸;同时,在槽外采用Ce4+氧化甲苯生成苯甲醛.实验结果表明,阴极和阳极电解的平均电流效率分别为92.71%和87.81%,总的电流效率高达180.52%;且Ce4+槽外氧化甲苯为苯甲醛的收率为95.78%,马来酸电还原为丁二酸的转化率为92.09%;电解的槽电压与单一电解氧化Ce3+相比降低了0.25 V.
This paper describes an effective method for determining ciprofloxacin lactate. An excess of sodium tetraphenylboron was added to precipitate ciprofloxacin lactate in HAc-NaAc buffer solution (pH=4.0). After filtering off the precipitate, the excessive sodium tetraphenylboron in the filtrate was titrated with cetyltrimethylammonium bromide standard solution, with bromophenol blue as indicator. The method is simple and rapid, it has been applied to the determination of ciprofloxacin lactate raw material with satisfactory results. The recovery was between 99.66% and 100.2%, the relative error was less than ±0.40%. Experiments showed that the method gave the same results as the approach using nonaqueous titration (ChP).
