An analytical method for an insecticide Fipronil and its metabolite MB 46513 remaining in agricaitunil products has been established which uses GC-ECD and GC/MS for their determination and continuation, respectively. In this method, target compounds are extracted with acetone from agricultural products, concentated, and finally re-extracted with n-hexane. When the sample contains lipid in large quantity, it is first delipidated by partition with acetonitrile, cleaned up with Florisil column, and finally determined by GC-ECD. In the case of vegetables and fruits, which contain lipids in small quantity, the sample is cleaned up with a Florisil column and determined by GOECD. The detection limit of this method is 0.001 micro g/g for both of these kind of samples, the recovery of Fipronil is over 85%, and the C. V. of the recovery is less than 7%. For MB-46513. the recovery is over 63% and its C. V. is less than 9%. This method was applied to 17kinds of agricultural products and no Fipronil and MB46513 were detected.

A method by GC/MS has been established for the determination of dimethenamid and cyhalofop-butyl in agricaltural products. Dimethenamid and cyhalofop-butyl were extracted with acetone, concentrated, and re - extracted with n - hexane. The extracts were cleaned up acetonitrile partitioning and florisil column, then determined by GC/MS-SIM. This method was featured of recovery over 75% and it's C.V. below 6%. The detection limits for dimetenamid and cyharofop-butyl were 0.001 micro g/g and 0.002 micro g/g, respectively.

A micro analytical method has been established for aliphatic lower primary and secondary amines in environmental water and sediment. Amines were distilled and allowed to react with benzenesulfonyl chloride under an alkaline condition. The derivatized compounds were extracted with benzene under an acidic condition and subjected to a determination by GC/MS. This method has been successfully applied for a simultaneous determination of primary and secondary amines with recovery over 80%, except for methylamine, and C.V. below 7%, except for methyl and dimethyl amines; moreover, the detection limit were 0.1 micro g/L for all of the amines determinated. This method is excelent also in sensitivity, is sufficiently applicable to environmental samples.

Analytical method for hydrophilic polar environmental pollutants was studied. Among these pollutants, the halogenated lower carboxylates were the target compounds of this investigation. A novel but simple derivatization method necessary for sample preparation for instrumental analysis was developed. The new derivatization method for the carboxylates is not a conventional chemical reaction in non-aqueous solvent following isolation from the environmental samples but rather, a direct aqueous reaction ; direct conversion of the carboxylates to amides using a carbodiimide in dilute aqueous solution. Halogenoanilines were selectively used with dicyclohexylcarbodiimide (DCC) under acidic conditions at room temperature to form the anilide derivatives. Moreover, this reaction proceeds while mixing the sample water, DCC, a halogenoaniline, and small volume of extracting solvent. Thus, for the first time, simultaneous derivatization of the carboxylates and extraction of the products into solvent was achieved. Based on the results, simple and practical determination methods by gas chromatography were developed for traces of these carboxylates in environmental samples and the proposed methods were applied to some real samples. Such analytical derivatization methods for carboxylates are useful and noteworthy because they can form C-N bonds in aqueous media under mild conditions with carbodiimides and N atoms of amino and other compounds.

A method by GC/MS has been established for the determination of Etoxazole in agricaltural products. Etoxazole was decomposed by acid contained in citrus fruits, but this decomposition could be prevented by addition of sodium acetate solution and extraction above pH 4. In the present method, the Etoxazole in agricultural products was extracted with acetone above pH 4, concentrated, and reextracted with n-hexane. After partition with acetonitrile followed by chromatographic clean-up with Florisil, the sample was subjected to GC/MS. The present method is excellent in sensitivity and has a detection limit of 0.002 micro g/g, and thus is about 10 times as sensitive as that of GC-NPD. The recovery by the present method is over 85% except for tea, the C.V. of recovery is less than 8%, and the method is applicable to actual samples.