Portal de Periódicos da CAPES

Do zwitterions contribute to the ionic strength of a solution?

2007; Elsevier BV; Volume: 373; Issue: 2 Linguagem: Inglês

10.1016/j.ab.2007.10.038

1096-0309

Earle Stellwagen, Jason D. Prantner, Nancy C. Stellwagen,

Surfactants and Colloidal Systems

Capillary electrophoresis has been used to determine whether zwitterions contribute to the ionic strength of a solution, by measuring the mobility of a double-stranded DNA oligomer in cacodylate-buffered solutions containing various concentrations of the ionic salt tetraethylammonium chloride (TEA+Cl−) or the zwitterion tricine+/−. The mobility of the DNA decreased as the square root of ionic strength, as expected from the Debye-Hückel-Onsager theory of electrophoresis, when TEA+Cl− was added to the buffer. However, the mobility was independent of the concentration of added tricine+/−. Hence, zwitterions do not contribute to the ionic strength of a solution.