“…This increased attraction is manifested as an increase in the magnitude of ion pairing between these charges and the formation of new pairs such as triple pairs that would not otherwise form in aqueous solutions. The most widely used standard methods for the determination of association constants include potentiometry (e.g., Doe et al, 1987;Gaizer et al, 1985;Mui and McBride, 1974;Višić et al, 1993Višić et al, , 1994Višić and Makjević, 1996b;Višić et al, 1999), spectrophotometry (Ghasemi et al, 2002), conductometry (e.g., D'Aprano et al, 1993;Doe et al, 1990;Evers and Knox;Gregorowicz et al, 1998Gregorowicz et al, , 1999Niazi et al, 1993aNiazi et al, , 1993bSokol et al, 2005;Srour and McDonald, 2008a), and ion-exchange equilibrium methods (Morris and Short, 1961;Patil and Sharma 1968;Pesavento and Alberti, 2000). Other methods such as specific ion electromotive force (EMF) measurements , NMR, and polarography are used under specific circumstances (Martell and Motekaitis, 1992).…”