Nitrobiphenyl ethers are used as herbicides all over the world, especiallyin J apan. 2, 4, 6-T richloro 4'-nitrobiphenylether (CNP) produced by chlorination of 2, 4-dichloro 4'- nitrobiphenyl ether (NIP) is extensively applied to rice fields. However, the wide application of CNP and NIP has resulted in environmental pollution (WATANhBE et al. 1983). Moreover, NIP was reported to be carcinogenic (QUEST et al. 1989) and CNP is under suspicion in ...