The Environmental Protection Agency's Environmental Monitoring and Support Laboratory at Cincinnati has been engaged in the development of test procedures for a multitude of organics in water. Midwest Research Institute was contracted to perform in a development program directed toward a group of 58 pesticides. The objective was to develop procedures that were as similar to each other as possible and were sensitive to 1 micrograms/liter. By using a standard method, at least as a starting point, and making adjustment as necessary, the number of unique procedures was kept to a minimum. The experimental approach was to test each pesticide against the standard method, e.g., methylene chloride extraction--Kuderna-Danish evaporation--Florisil cleanup--gas chromatographic determination. Problem areas such as poor recovery, inadequate cleanup, etc., were identified and modifications to circumvent these problems were devised. One major deviation was the use of HPLC for several classes of pesticides. The general classes or individual pesticides studies (and the number of compounds in the classes) were: organochlorine (6); organonitrogen (7); organophosphorus (19); triazines (9); carbamates and ureas (7); carbendazin and benomyl; cyanazine; carbofuran; 4,4'-methylene-bis(2-chloroaniline); dinoseb; tokuthion; piperalin; piperonyl butoxide; and aldicarb.