Switchable-hydrophilicity solvent-based liquid phase microextraction for determination of brilliant green in water, shellfish, and fish samples

To avoid substances harmful to the environment and humans, reducing residues generated during chemical tests and substituting solvents has attracted much interest from the scientific community. This study introduces an innovative approach, harnessing switchable-hydrophilicity solvent-based liquid phase microextraction to determine brilliant green. The microextraction process is based on the dispersion of a switchable-hydrophilicity solvent (octanoic acid) for the preconcentration of brilliant green. The alternation between these two forms, hydrophobic (immiscible) and hydrophilic (miscible), can be obtained by changing the composition of the solution, where sodium bicarbonate and sulfuric acid were employed. Factors such as pH, sample volume, switchable solvent volume, and acid-base ratio were optimized to obtain the best analytical response for brilliant green preconcentration. The detection limit was 1.4 μg/L, and the enrichment factor was 250. This novel method successfully assessed brilliant green levels in water, shellfish, and fish samples. It emerges as an accessible, cost-effective, and eco-conscious alternative for quantifying brilliant green, aligning seamlessly with the mission to protect the environment and human health.