A new generation of nano-structured supramolecular solvents based on propanol/gemini surfactant for liquid phase microextraction

- A supramolecular solvent (SUPRAS) made up of aggregates of gemini surfactant was introduced.
- A microextraction method, based on the SUPRAS was applied for extraction of parabens.
- Separation and determination of the parabens was performed by HPLC-UV.
- Parameters affecting extraction of the analytes were optimized by one variable at a time method.
- Under the optimal conditions, the preconcentration factors in the range of 98-156 were obtained.

A new supramolecular solvent (SUPRAS) made up of aggregates of gemini surfactant was introduced. A microextraction method, based on the SUPRAS followed with high performance liquid chromatography-ultraviolet detection, was applied for the determination of parabens in cosmetics, beverages and water samples. A SUPRAS is a nano-structured liquid made up of surfactant aggregates synthesized through a self-assembly process. In the present work, a new gemini-based SUPRAS was introduced. Methyl paraben (MP), ethyl paraben (EP), and propyl paraben (PP) were extracted on the basis of π-cation and Van der Waals interactions into the SUPRAS. The parameter affecting the extraction of target analytes (i.e., the amount of surfactant and volume of propanol as major components comprising the supramolecular solvent, sample solution pH, salt addition, ultrasonic and centrifugation time) were investigated and optimized by one-variable-at-a-time method. Under the optimum conditions, the preconcentration factors of 98, 143 and 156 were obtained for MP, EP and PP, respectively. The linearity ranged from 0.5 to 0.7-200 μg L−1 with the correlation of determination of (R2) ≥ 0.9938. The gemini-based SUPRAS followed by HPLC-UV has been found to have excellent detection sensitivity with a limit of detection (LOD, S/N = 3) of 0.5 μg L−1 for EP and PP, and 0.7 μg L−1 for MP. Good recoveries over the range of 92.0-108.3% assured the accuracy of the amount of parabens distinguished in the non-spiked samples.

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