Gas-liquid chromatographic determination of chlordimeform and its metabolites in cargo rice and husk

A specific method is described for the alkali flame ionization gas-liquid chromatographic determination of chlordimeform (N'-(4-chloro-o-tolyl)-N,N-dimethylformamidine) and 3 potential metabolites in cargo rice and husk. Samples are extracted with absolute alcohol or hexane, and cleaned up on neutral alumina columns. Residues of chlordimeform and its metabolites are chromatographed directly on a column of 1% DEGS coated on 60-80 mesh 405 support (PEG 20M bonded phase). The detection limits for chlordimeform, 4-chloro-o-toluidine, 2,2'-dimethyl-4,4'-dichloroazobenzene, and N-formyl-(4-chloro-o-toluidine) are 0.03, 0.028, 0.11, and 0.43 ppm for cargo rice and 0.03, 0.028, 0.22 and 0.43 ppm for husk, respectively.