The distribution, elimination, and in vivo biotransformation of aldicarb in the rainbow trout (Oncorhynchus mykiss).

The distribution and elimination of [14C]aldicarb, administered orally and by intraperitoneal (ip) injection, was examined in the rainbow trout (Oncorhynchus mykiss). Tissue residues were determined by monitoring radioactivity at various time periods up to 96 hr in trout administered [14C]aldicarb orally. Periodic water samples and a single tissue residue radioactivity level were obtained after 24 hr in free swimming and spinally transected fish which received [14C]aldicarb via intraperitoneal injection. Aldicarb appears to be absorbed rapidly (99% within 3 hr) and distributed to all tissues. Elimination profiles from both dosage groups demonstrate a rapid alpha phase (oral 24 hr; ip 3 hr) probably due to branchial excretion (96% after ip injection) followed by a slower beta phase (oral 107 hr; ip 28 hr) suggesting a deeper compartment such as muscle. [14C]Aldicarb and/or its metabolites were slowly being transported to the bile after 24 hr. The in vivo biotransformation of [14C]aldicarb was examined in spinally transected trout 24 hr after ip injection. The major metabolite found was aldicarb sulfoxide (7.6%) along with lesser amounts of aldicarb oxime (5.4%).