SEPARATION OF NONIONIC COMPOUNDS BY CE USING A LAURYL POLY(OXYETHYLENE) SULFATE ADDITIVE

A nonionic surfactant (Brij-30) was treated with chlorosulfonic acid t o form C12H25(OCH2CH2)(4)OSO3-Na+. Addition of a low concentration of this material to an aqueous solution-acetonitrile electrolyte makes it possible to separate nonionic organic compounds by capillary electrop horesis. Separation is based on differences in the stabilities of anal yte-additive complexes in solution. Migration times of analytes can be varied over an unusually large range by varying the additive concentr ation and the proportion of acetonitrile in the electrolyte. This grea tly expands the scope of neutral organic compounds that can be separat ed by CE. Several examples are given. Some very difficult separations were achieved, such as the baseline resolution of four methylbenz[a]an thracene isomers and the separation of normal and deuterated acetophen one.