Abstract
1. 6,7-Dimethylquinoline (6,7-DMQ) is readily taken up by rainbow trout and bioconcentrated in tissue after exposure to ca 1 mg/1 for 7.5 h. Mean bioconcentration factors (from water) were 21, 18, 6 and 14 for bile, liver, muscle and carcass respectively. Mean tissue concentrations after 69-96 h depuration were ND, ND, 0.54 and 0.48 μg/g for bile, liver, muscle and carcass respectively.
2. Major metabolites, following exposure to 6,7-DMQ, were conjugates (glucuronide or sulphate) of 7-hydroxymethyl-6-methylquinoline and 6-hydroxymethyl-7-methylquinoline. Mean concentration of metabolites in the bile were 500μg/g after 7.5 h exposure to ca 1 mg/1 and 1367 μg/g after 9.5 h exposure to ca 1 mg/1 and 69 h depuration.
3. 6,8-Dimethylquinoline (6,8-DMQ) is also readily bioconcentrated in fish tissue after exposure to ca 1 mg/1. Mean bioconcentration factors (from water) were 23, 20, 13 and 25 for bile, liver, muscle and carcass respectively. Mean tissue concentrations after 7 h exposure to ca 1 mg/1 and 63 h depuration were 4.0,0.67,0.49, and 3.2 μg/g respectively for bile, liver, muscle and carcass.
4. Major metabolites, following exposure to 6,8-DMQ were conjugates (glucuronide or sulphate) of 6,8-dimethyl-5-hydroxyquinoline, 6,8-dimethyl-7-hydroxyquinoline. 6,8-dimethyl-3-hydroxyquinoline and 6-hydroxymethyl-8-methylquinoline. Mean concentration of metabolites in the bile were 1278 μg/g after exposure to ca 1 mg/1 for 8 h and 1031 μg after exposure to ca 1 mg/1 for 7h and 63 h depuration.