Abstract: This invention is directed to a preparative technique for concentrating or isolating a surfactant from an oil/water emulsion. First, a an emulsion or sludge sample containing surfactants is separated into separate oil, water and solid phases. Thereafter, water droplets are injected into the oil phase. The water droplets fall through the oil phase, causing surfactant in the oil phase to adhere to said droplets which form a high-internal-phase-ratio (HIPR) water-in-oil emulsion that is rich in surfactants. This emulsion is subsequently separated into an oil and a water phase. The separated surfactant-rich oil phase is then analyzed to obtain information concerning the surfactant.