两相滴定法近年来应用较多,所用的滴定剂有酸性染料、阴离子或阳离子表面活性剂及四苯硼酸钠等。本法用酸性染料为滴定剂,是由酸性染料比色法发展而来,酸性染料在一定 pH 下可与生物碱类以一定比例结合,结合物用适当的有机溶剂提取,水相不显颜色;过等当点后,稍过量的染料即存于水相中而使水相变色指示出终点。 The two-phase titration method has been widely used in recent years. The titrants used include acid dyes, anionic or cationic surfactants, and sodium tetraphenylborate. This method uses acid dyes as titrants and is developed from the acid dye colorimetric method. Acid dyes can be combined with alkaloids in a certain ratio at a certain pH, and the conjugates are extracted with appropriate organic solvents. The aqueous phase is invisible After passing the waiting point, a slight excess of dye is stored in the aqueous phase and the color change of the aqueous phase indicates the end point.