OPTIMIZATION OF THE SEPARATION SELECTIVITY OF A GROUP OF BENZENE AND NAPHTHALENE DERIVATIVES IN MICELLAR HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY USING A C-18 COLUMN AND ALCOHOLS AS MODIFIERS IN THE MOBILE-PHASE

The separation selectivity of fifteen benzene and naphthalene derivatives in micellar high-performance liquid chromatography, using a C18 column, was studied as a function of the parameters on which it depends. A multiple linear regression programme was used to find the dependence of the selectivity coefficient on the following parameters: nature of the surfactant in the mobile phase (sodium dodecyl sulphate or hexadecyltrimethytammonium bromide), surfactant concentration (0.02-0.1 M), nature of the additive in the mobile phase (methanol. n-propanol, n-butanol and sodium chloride) and percentage of the alcohol (0, 5 or 10%). Selectivity optimization corresponds to the use of sodium dodecyl sulphate at low concentrations and the addition of an alcohol of medium chain length.