Loofah sponge-based solid-phase extraction in combination with high-performance liquid chromatography-fluorescence detection (HPLC-FLD) for analysis of bisphenols in environmental water

Loofah sponges (LS) were simply treated by alkaline solution and then used as solid-phase extraction (SPE) adsorbent to extract bisphenols from environmental water samples for the first time. As naturally material, LS exhibited an excellent adsorption performance for bisphenol compounds due to their particular functional groups such as hydroxyl, carboxyl, amino, and other active groups. Key extraction conditions were optimized, including adsorbent amount, washing solvent volume, sample pH, ionic strength, sample loading flow rate, eluent type, and elution solvent volume. Under the optimal extraction conditions (200 mg adsorbent amount and 5.0 mL eluent volume), a method was developed for analyzing five bisphenols in environmental waters by combining LS-based SPE with high-performance liquid chromatography-fluorescence detection (HPLC-FLD). This analytical method showed excellent linearity within BP concentration range of 0.5-500 ng/mL and low detection limits (0.077-0.225 ng/mL). The recoveries of five bisphenols ranged from 78.6 % to 112 % with inter-day and inter-day precision less than 5.1 %. This method was successfully applied to the analysis of bisphenols in water samples with various water sources including river, lake, tap water, bottled water, and barrelled water. The proposed analytical method is low-cost, efficient, and sensitive, offering an alternative strategy for monitoring bisphenols in enviromental water.