In this paper, the influence of substituents in sulfonephthalein acid dye onthe spectral properties of their dye ion-pair complex with methylene blue basic dye hasbeen studied, when using 1, 2-dichloroethane as extractant.是什么意思 In this paper, the influence of substituents in sulfonephthalein acid dye onthe spectral properties of their dye ion-pair complex with methylene blue basic dye hasbeen studied, when using 1, 2-dichloroethane as extractant.怎么读