Sulfonated polystyrene-divinylbenzene resins are described for solid phase extraction (SPE). The degree of sulfonation was found to play a vital role in determining the efficiency of these resins. An optimum sulfonation capacity of 0.6 mequiv/g was determined by measuring the capacity factor of several organic compounds in water. Loose sulfonated resin and an Empore°ler membrane embedded with sulfonated resin were used for SPE. The Empore membrane yielded average recoveries greater than 95% for a wide variety of compounds. A sulfonated Empore membrane also produced sharper and more efficient breakthrough than a membrane embedded with unsulfonated resin;The use of organic eluents for the ion-exchange separation of alkali metals and organic amines is discussed. Retention of alkali cations generally increased as the organic content in the eluent increased, although a maximum was found at 75% organic for several cations. Organic eluents increased separation factors and altered elution order. The effect of 18-crown-6 in the mobile phase was also investigated. 18-crown-6 changed elution order and improved peak shape. Unique separations were obtained;The use of organic eluents for the separation of amines effectively removes all hydrophobic interaction and permits true ion-exchange selectivity to be measured. Capacity factors for a series of protonated amine cations were measured in several organic eluents containing methanesulfonic acid. Little change is observed with increasing carbon chain length in n-alkylamine cations, but substantial differences were seen at fixed eluent concentrations for different organic eluents. Several practical separations of organic amine cations were demonstrated in non-aqueous media;Silicalite, a silica-based molecular sieve, was used as an HPLC stationary phase for the separation of many organic compounds. Silicalite possess hydrophobic channels approximately 6 A in diameter. This size-exclusion property is another selectivity mechanism that was utilized to obtain unique separations. Cis/trans isomers were separated very efficiently on this stationary phase. Comparisons between Silicalite and silica-C18 are shown along with several separations that demonstrate the capabilities and limitations of Silicalite as an HPLC stationary phase.