日本分析化学会 Acta Medica Okayama 0525-1931 53 9 2004 シアニン系新規合成試薬を用いる陰イオン界面活性剤の定量 919 923 EN Akinori Goto Mitsuko Oshima Toshio Takayanagi Shoji Motomizu For the spectrophotometric determination of anionic surfactants in aqueous media, cationic dyes with a 2,2'-thiacyanine skeleton were newly synthesized. Carbon numbers of 4 and 6 in the n-dialkyl chain combined at the N position of 2,2'-thiacyanine are new compounds. Fundamental information, such as the (p)K(a) values, was obtained. These two compounds and purchased diethyl- and dipropyl-2,2'-thiacyanine were examined for the spectrophotometric determination of an anionic surfactant, DBS. Of these, 3,3'-dihexyl-2,2'-thiacyanine (DHT) showed the best sensitivity. The calibration graph for DBS with DHT was linear up to 1×10(−5) M, and the detection limit was 4×10(−7) M. By a hydrophobic interaction, even a cationic surfactant, Zephiramine, and a nonionic surfactant, Triton X-100, could react with DHT. The ion-association constants for these surfactants with DHT were obtained. No potential conflict of interest relevant to this article was reported.