Novel solid-phase extraction promotes simultaneous colloidal gold immunochromatographic assay of malachite green, leuco-malachite green, chloramphenicol, and semi-carbazone metabolites in aquatic products

Solid phase extraction (SPE) using traditional column materials offers several advantages, but its ability to simultaneously extract and purify commonly used veterinary drugs, such as chloramphenicol, malachite green, leuco-malachite green and semi-carbazone, remains unproven.Therefore, in the present study, a rapid analytical method based on ultrasound-assisted SPE combined with colloidal gold test strips was developed and applied herein to determine the residues of these veterinary drugs in common aquatic products. Under optimized conditions, the method achieved a limit of detection in the range of 0.01–0.5 μg/kg, inter-day RSDs of the spiked samples in the ranges of 0.99–5.58 % and 1.6–7.2 %, and absolute recoveries in the range of 84.2–112.9 % using the colloidal gold immunoassay and enzyme-linked immunosorbent assay methods, respectively. The SPE column efficiently enriched the four veterinary drugs simultaneously, showing considerable potential for determining common veterinary drug residues in aquatic products.