Simultaneous determination of anionic, amphoteric and cationic surfactants mixtures in surface water

Abstract

A simple, reliable and accurate HPLC/CAD method was developed for the determination of anionic (sodium dioctyl sulfosuccinate and sodium 1-dodecane sulfonate), amphoteric (CHAPS (3-[(3-Cholamidopropyl) dimethylammonium]-1-propanesulfonate hydrate)) and cationic (benzethonium chloride) surfactants mixture from surface water samples. The chromatographic analysis was performed on an Acclaim Surfactant Plus (150 x 3.0 mm, 3µm d.p.) column acquired from Thermo Scientific, kept at 300C. All experiments were performed in gradient elution conditions at a flow-rate of 0.6 mL/min. Mobile phase composition was a mixture of acetonitrile (A) and 0.1 M ammonium acetate solution acidified to pH 5 with acetic acid (B). The limit of detection (LD) were 20µg/L for anionic surfactants and 30µg/L for cationic and amphoteric surfactants. The calibration curves were linear between 15 mg/L – 110 mg/L, with R2 values above 0.992 for all surfactants. Solid phase extraction (SPE) using polymeric (Strata X) cartridges has been applied to extract and concentrate the target analytes from the synthetic samples. Surfactants recoveries after SPE procedure were situated between 91.5÷94.6%. Intra-day and inter-day precision (RSD%) were situated between 4.0 ÷ 7.7% and 7.5 ÷ 11.7%, respectively. Limit of quantitation (LQ) was lower than 80µg/L for anionic surfactants and 90µg/L for cationic and 100µg/L for amphoteric surfactants. The new sensitive and selective HPLC/CAD developed method allows simultaneous determination of anionic, amphoteric and cationic surfactants mixture from environmental samples (surface water).