title: Rapid and simple immunochemical screening combined with hand-shaking extraction for thiamethoxam residue in agricultural products.
abstract: BACKGROUND
  With the aim of expanding the applicability of a kit-based enzyme-linked immunosorbent assay (ELISA) for the neonicotinoid insecticide thiamethoxam, the ELISA was newly applied to three kinds of agricultural samples (green pepper, eggplant and spinach). To offer the ELISA as a screening analysis for thiamethoxam residues, a rapid and simple method of extraction by hand-shaking was used, and speed-up and simplification of the sample treatment before the ELISA analysis were examined. Finally, the validity of the ELISA combined with the proposed extraction method was verified against a reference high-performance liquid chromatography (HPLC) method using real-world agricultural samples.
  
  
  RESULTS
  There were no marked matrix effects derived from green pepper and eggplant extracts. On the other hand, although the effect due to a pigment in spinach extract on the assay performance was significant, it was effectively avoided by increasing the dilution level of the spinach extract. For thiamethoxam-spiked samples, acceptable recoveries of 97.9-109.1% and coefficients of variation of 0.3-11.5% were obtained. Inspection of the validity of the ELISA by comparison with the reference HPLC method showed that the two analytical results were very similar, and a high correlation was found between them (r>0.997).
  
  
  CONCLUSIONS
  The evaluated ELISA combined with hand-shaking extraction provided a rapid and simple screening analysis that was quantitative and reliable for the detection of thiamethoxam in complex agricultural products.
authors.affiliation: National Institute for Agro-Environmental Sciences, Tsukuba, Ibaraki, 305-8604, Japan. eikiw@affrc.go.jp
authors.forename: Eiki
authors.initials: E
authors.lastname: Watanabe
authors.forename: Yuso
authors.initials: Y
authors.lastname: Kobara
authors.forename: Shiro
authors.initials: S
authors.lastname: Miyake
mesh_terms: D018556:Crops, Agricultural / Q000737:chemistry*; D004797:Enzyme-Linked Immunosorbent Assay; D005506:Food Contamination / Q000032:analysis*; D007306:Insecticides / Q000737:chemistry*; D000073943:Neonicotinoids; D009574:Nitro Compounds / Q000737:chemistry*; D010078:Oxazines / Q000737:chemistry*; D010573:Pesticide Residues / Q000737:chemistry*; D000077922:Thiamethoxam; D013844:Thiazoles / Q000737:chemistry*
chemical_list: D007306:Insecticides; D000073943:Neonicotinoids; D009574:Nitro Compounds; D010078:Oxazines; D010573:Pesticide Residues; D013844:Thiazoles; D000077922:Thiamethoxam