日本分析化学会 Acta Medica Okayama 0910-6340 6 5 1990 Liquid-Liquid Extraction Behavior of Inorganic and Organic Anions with Color-Changeable Neutral Extractants 737 745 EN Shoji Motomizu Color-changeable extractants for acids, acidophores, were synthesized and examined; they were 4-(N, N dimethylaminophenylazo)-pyridines and quinolines. The fundamental physicochemical constants for the acidophores and their ion associates were determined by spectrophotometry. The liquid-liquid distribution was carried out between an aqueous phase and a chloroform phase. A parameter of the extractability of the protonated cations of the acidophores and of several inorganic and organic anions as ion associates was determined on the basis of the assumption that the extraction constant of an ion association complex, log K(ex), is divided into a cationic and an anionic contributions, C and A, respectively. The order of the extractability of the anions was: Br(-)<I(-)<ClO(4)(-)<SCN(-)<Pic(-)<(Ethyl range)(-)<C(12)H(25)-OSO(3)(-). Anionic surfactants could be quantitatively extracted into chloroform with 4-(4-N, N-dimethylaminophenylazo)-2-methylquinoline: the molar absorptivity was 4.5×10(4)l mol(-1) cm(-1) at 560nm. The acidophores once used could be recycled and be used repeatedly. No potential conflict of interest relevant to this article was reported.

日本分析化学会 Acta Medica Okayama 0910-6340 6 5 1990 Batchwise and Flow-Injection Methods for the Spectrophotometric Determination of Anionic Surfactants with 4-(4-N, N-Dimethyl- aminophenylazo)-2-methylquinoline 705 709 EN Shoji Motomizu solvent-extraction Spectrophotometric method for the determination of anionic surfactants in water was developed with -(4-N, N-dimethylaminophenylazo)-2-methylquinoline (MQ) by batchwise and flow-injection techniques. The ion associates of MQ with anionic surfactants extracted into an organic phase showed a blue shift of the maximum absorption wavelength; their molar absorptivities were 4.5×10(4)l mol(-1) cm(-1) at 560nm. In the batchwise method, a 40-fold extraction concentration was possible. In the 20-fold concentration, the calibration graph was linear at concentration ranging from 1×10(-8)M to 7.5×10(-7)M of anionic surfactants, and the mean absorbances of the reagent blank and the 5×10(-7)M anionic surfactant (dodecylsulfate : LS(-)) were 0.024 and 0.518, respectively; the relative standard deviation for 10 measurements of 5×10(-7)M LS(-) was 0.28%. Foreign ions generally existing in river water did not interfere with the determination. This solvent-extraction spectrophotometric method was satisfactorily applied to a flow-injection method. The reagent MQ was recycled and repeatedly used at least for 7 months, and the efficiency of the reagent has not changed during at least this period. No potential conflict of interest relevant to this article was reported.