Department of Chemistry, University of Mazandaran , P. O. Box 453, Babolsar, I. R. IRAN
Separation of ten sedative- hypnotic drugs was performed by RP-HPLC using mixed micellar mobile phase. Effect of temperature, type and amount of organic modifier in mobile phase on efficiency (N) and asymmetry factor (B/A) showed that, the appropriate conditions for a good separation were 35°C and 7% (V/V) butanol in mobile phase. Variations of selectivity factor versus butanol concentration, Mixture of SDS/ Brij- 35 concentrations and pH of mobile phase showed that the appropriate conditions were 7%(V/V), 15 mM SDS +1.0mM Brij-35 and pH=3 in mobile phase respectively.