Abstract: Sample solution of river water or acetone extract of soil sample was passed through either a set of 3 immunoaffinity chromatographic columns (IAC) connected in series in which immunoaffinity sorbents of carbofuran, triaophos and chlorsulfuran were filled separately, or through a multi-antibody IAC in which the 3 immunoaffinity sorbents were filled together, to separate the 3 pesticides, carbofuran, triaophos and chlorsulfuran, from the sample solution. When the IAC in series was used in separation, the 3 columns were disconnected after passing-through of the sample solution, and each of the columns was eluted with mixtures of CH3OH and H2O (mixed in different ratios). Amounts of carbofuran, triaophos and chlorsulfuran were determined by ELISA and HPLC separately in the respective eluates from the columns. When the multi-antibody IAC was used in separation, the 3 pesticides in the eluate were determined simultaneously by ELISA and HPLC separately. Tests for recovery and precision for the 2 methods of separation were made, giving consistent results of recovery and repeatability between the 2 methods.