- Development of an enzyme-linked immunosorbent assay for the insecticide thiamethoxam
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An enzyme-linked immunosorbent assay (ELISA) was developed for the neonicotinoid insecticide thiamethoxam, 3-(2-chlorothiazol-5-ylmethyl)-5-methyl-4-nitroimino-1,3,5-oxadiazinane. Three antisera were raised from rabbits immunized with the hapten - KLH conjugate. On the basis of the computational analysis of hapten candidates, the hapten with a spacer arm on the thiazolyl ring of thiamethoxam was synthesized to elicit thiamethoxam-specific antisera. The hapten was 3-[2-(2-carboxyethylthio)-5-ylmethyl]-5-methyl-4-nitroimino-1,3, 5-oxadiazinane. Antisera were characterized with indirect competitive ELISA. Cross-reactivity and effects of organic solvents, pH, and ionic strengths were evaluated. The antiserum was specific for thiamethoxam and tolerant of up to 5% acetonitrile and 5% acetone. Various ionic strengths and pH values in the tested ranges had negligible effect on the assay performance. Under the optimized conditions, the half-maximal inhibition concentration (IC50) and the limit of detection were approximately 9.0 and 0.1 μg/L of thiamethoxam, respectively. ELISA analysis of stream and tap water samples showed an excellent correlation with the fortification levels.
- Kim, Hee-Joo,Liu, Shangzhong,Keum, Young-Soo,Li, Qing X.
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p. 1823 - 1830
(2007/10/03)
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- Process for the preparation of thiazole derivatives
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A process for the preparation of a compound of formula (I), wherein X is a leaving group; which process comprises, a) for the preparation of a compound of formula (I) wherein X is —OS(═O)2A and A is as defined in the specification, reacting a compound of formula (II) with a sulfonylating agent; or, b) for the preparation of a compound of formula (I) wherein X is iodine, reacting a compound of formula (III) with an iodinating agent, preferably sodium iodide; or, c) for the preparation of a compound of formula (I) whrein X is bromine, reacting a compound of formula (IV) with a brominating agent; or, d) for the preparation of a compound (I) wherein X is chlorine or bromine, reacting a compound (V), wherein R and X are as defined in the specification, with a chlorinating agent, a compound of formula (Ib), the use thereof and a process for the preparation of a compound of formula (II) and a compound of formula (A) are described.
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