Quantum dots and cationic carrier‐reinforced electromembrane extraction of typical illegal dyes in fish samples followed by capillary electrophoresis with contactless conductivity detection

Abstract BACKGROUND Malachite green and crystal violet have been attracting wide attention due to their potential hazards to the environment and human health. Due to the complexity of the real sample matrix and the low contents of the target analytes, green sample pretreatment methods have become a research hotspot. RESULTS In this work, electromembrane extraction reinforced by quantum dots and a cationic carrier (tris(2‐ethylhexyl) (phosphate) was applied to the purification and enrichment of the interested illegal dye additives in aquatic products. The obtained extract could be directly analyzed by the integrated system of capillary electrophoresis with capacitively coupled contactless conductivity detection. The main experimental parameters influencing separation and extraction were investigated in detail. Under the optimum conditions, the limits of detection attained 5.6–15 ng mL −1 (signal‐to‐noise ratio ( S/N ) = 3) in the fish sample matrix, and the enrichment factors were in the range of 70 to 205 times. This developed method was successfully carried out for the analyses of fish samples, and the recovery data ranged from 97.0% to 118%. Furthermore, the greenness and eco‐friendliness of this method was assessed by the green analytical procedure index and analytical eco‐scale tools. CONCLUSION This proposed method is easy to operate and requires no derivatization, providing an alternative for the fast analysis of illegal dye additives in the real‐world fish samples. © 2026 Society of Chemical Industry.