Sample digestion for determining chloramphenicol residues in carp serum and muscle

Chloramphenicol (CAP) residues in carp (Cyprinus carpio L.) were investigated after intramuscular injection of a single-dose of 80 mg/kgbw. CAP concentrations in carp serum and muscle with and without addition of β-glucuronidase were determined by high-performance liquid chromatography (HPLC) with UV detection. The results showed that CAP-glucuronide (CAP-G), an important conjugate of CAP in the metabolic process and potentially toxic to human health, was observed after the fish were injected with CAP. CAP concentrations in serum and muscle with added β-glucuronidase were significantly (p < 0.05) higher than those without added enzyme. For example, within 24 h of injection, average CAP concentrations in serum and muscle with enzyme digestion were 30 and 48% more than those without the enzyme. In order to exactly determine the trace CAP content of fish, for evaluation of food safety, it is suggested that samples be hydrolyzed with enzyme (e.g., β-glucuronidase).