This paper presents the values of the micellar binding constants of Ni(II), Co(II) and Cu(II) as complexes with sodium diethyldithiocarbamate, DDTC, in presence of hexadecyltrimethylammonium bromide, CTAB, and sodium dodecylsulphate, SDS, with larger amounts of n-Propanol as organic modifier, by High Performance Liquid Chromatography. Binding constants have been obtained from two equations: a) Arunyanart's treatment, very used for organic compounds but that is not take into account the influence of modifier and b) a multiple regression analysis that permits to consider the high quantities of n-Propanol.