Sequential Extraction-Spectrofluorimetric Determination of Ultratraces of Zinc Using Cryptand 2.2.1 and Eosin

摘要

A highly sensitive and selective spectrofiuorimetric method has been developed for the determination of ultratraces of zinc, based on solvent extraction with 1,2-dichloroethane of the ion-pair formed between eosinate anion and the positively charged cryptate of zinc with cryptand ethers. The detection limit for zinc is 1.5ng/ml, and the linear working range up to 200ng/ml. The relative standard deviation is 1.8% at the 100 ng/ml level. The proposed method has been tested for determination of zinc in coal and fly ash.