KINETICS OF 4-CHLOROANILINE IN GUPPY, POECILIA-RETICULATA

The toxicokinetic behaviour of 4-chloroaniline (4CA) in the guppy (Poe cilia reticulata) was studied. In order to reduce the detection limit for quantitative analysis of 4-chloroaniline in guppy, a derivatizatio n method with heptafluorobutyric anhydride was applied. The observed b ioconcentration factor (BCF) was slightly higher than the estimated BC F value, based on a previously published linear relationship between l og BCF values and the logarithm of the octanol-water partition coeffic ient (K(ow)) for chlorobenzenes. A considerable amount of 4-chloroacet anilide was detected in the fish which indicates that guppies can biot ransform 4CA into the N-acetyl derivative. It is suggested, however, t hat this biotransformation does not influence the extent of bioconcent ration. The slightly higher BCF value may be attributed to a contribut ion of 4CA present in the aqueous phase in the fish to the total conce ntration of 4CA in the organism. The uptake rate constant of 4CA is lo wer than those determined for tri-, tetra-, and pentachloroanilines, w hich is in accordance with theoretical models. Furthermore, the elimin ation of 4CA is best described with a bi-exponential equation. Half-li ves of the initial and terminal elimination phases are compared with t he half-life of a compound for which elimination is best described by a monoexponential equation.