RESUMEN
The bioaccumulation of sulfadiazine and subsequent enzymatic activities in Chinese mitten crab (Eriocheir sinensis) were studied in microcosms, by exposing to 50, 100, 500 and 1000ng/L of sulfadiazine for 44days. An effective method for extracting sulfadiazine in crab tissues was established by modifying the cleanup method after ultrasound extraction, with improved recoveries of 61.8%, 93.7% and 100.5% in gill, muscle and liver samples. The results showed that sulfadiazine residues were all <3ng/g dry weight in different tissues, and that sulfadiazine bioaccumulation in crab was not dose-dependent. A significantly negative correlation was observed between acetylcholinesterase activity and the residue concentration of sulfadiazine during exposure to 50ng/L and 1000ng/L, and between alkaline phosphatase and sulfadiazine residues in the 100ng/L exposure group in the gill, suggesting that the two enzymes played an important role in the metabolism of sulfadiazine in crab.