SEPARATION OF 21 NAPHTHALENE SULFONATES BY MEANS OF CAPILLARY ELECTROPHORESIS

The production and use of naphthalene sulfonates can easily cause poll ution of surface and other types of waters. In the present study, capi llary electrophoresis in combination with UV absorption detection was used to separate 21 amino- and hydroxy-substituted naphthalene sulfona tes which included multiple isomeric compounds. The influence of vario us parameters such as pH (which turned out to be extremely important), temperature of the surrounding air flow, and the use of buffer additi ves (micelles, cyclodextrins, organic modifiers) was studied. Complete separation of all analytes including the isomers, was achieved in two runs with a 50 mM boric acid/borate buffer, containing either 100 mM sodium dodecylsulfonate or 15 % acetonitrile. The limits of detection obtained for the individual compounds typically were 20 mu g l(-1). Ri ver water samples spiked at this concentration level could be analysed using a simple three-step sample clean-up procedure.