18-冠-6对钾离子具有选择络合的特性,已用于钾的萃取光度或萤光光度测定,有的已将此法用于血清及水等样品中钾的测定~[1～3]。由于二苯并-18-冠-6的价格较低,而且熔点高、水溶性小、易于回收,如能代替18-冠-6,将更有利于冠醚类试剂的推广应用。近年来国外有这方面的报导,但存在着选择性差或有色试剂不易获得等向题~[4,5]。我们用二苯并-18-冠-6代替文献[1]所用的18-冠-6,以溴甲酚绿作 18-Crown-6 has the characteristic of selective complexation with potassium ion and has been used for the determination of potassium extraction luminosity or fluorescence spectrophotometry. Some of these have been used for the determination of potassium in serum and water samples. ]. Due to the lower price of dibenzo-18-crown-6, high melting point and low water solubility, it is easy to be recycled. If it can replace 18-crown-6, it will be more conducive to the popularization and application of crown ethers. In recent years, foreign reports in this area, but there is a poor selectivity or colored reagent is not easy to obtain the same title ~ [4,5]. We use dibenzo-18-crown-6 instead of the literature [1] 18-crown-6, with bromocresol green as