A method was optimized for the simultaneous analysis of anionic and non-ionic surfactants using an Aqueous/Organic (multi-solvent use) SEC column, Asahipak GF-210 HQ. Polyvinyl alcohol used for GF-210 HQ packed gel is slightly negatively charged. By using mobile phase without salt retains this negatively charged surface characteristic; this results in the fast elution of anionic surfactant by ion exclusion effect, and thus separates it from non-ionic surfactant. Meanwhile, addition of salt to the mobile phase suppresses the ion exclusion effect and retains the anionic surfactant, thus it is not separated from the non-ionic surfactant.


Sample : 50 μL
1. Sodium p-octylbenzenesulfonate 100 mg/L
2. Triton X-114 (Polyoxyethylene(8) octylphenyl ether) 1000 mg/L

Column       : Shodex Asahipak GF-210 HQ (7.5 mm I.D. x 300 mm)
Flow rate    : 0.8 mL/min
Detector     : UV (254 nm)
Column temp. : 40 °C