Application of dispersive liquid–liquid microextraction and high-performance liquid chromatography for the determination of cetrimonium bromide in water samples



A simple, rapid and sensitive
method for the determination of cetrimonium bromide at trace levels in water
samples was developed by combining a dispersive liquid –liquid
microextraction (DLLME) technique with high performance liquid chromatography
(HPLC-UV). A mixture of extraction solvent and dispersive solvent were
rapidly injected into 10.0 mL aqueous sample, and a cloudy solution was
formed. After extraction of the analyte into the fine droplets of extractant,
phase separation was performed by centrifugation and the enriched analyte in
the sedimented phase was determined by HPLC-UV. The factors relevant to the
microextraction efficiency, such as the kind and volume of extraction and
dispersive solvent, and the extraction time were optimized. Under the optimum
conditions (extraction solvent: chlorobenzene, volume, 70 μL dispersive
solvent: ethanol, volume, 0.75 mL), the enrichment factor of 200 was
obtained. The linear range was 0.005–100 µg L-1. The relative
standard deviation of 5.9% (n= 5), and detection limit (signal-to-noise ratio
of 3) of 0.10 pg mL-1 were obtained.