title: Facile and Sensitive Detection of Carbofuran Carbamate Pesticide in Rice and Soybean Using Coupling Reaction-based Surface-Enhanced Raman Scattering.
abstract: In this research, a sensitive and selective method for detecting one of the most toxic insecticides, "carbofuran", in rice and soybean is presented. This method is based on the coupling reaction of diazonium ion combined with a surface-enhanced Raman scattering technique. Diazonium ion produced from p-aminothiophenol reacts specifically with carbofuran phenol from the hydrolysis of carbofuran. The generated azo compounds attach to the surface of silver nanoparticles via the Ag-S bond. Therefore, a strong Raman intensity can be obtained. The concentration of carbofuran can be determined by following the intensity of the peak at 1201 cm-1, attributed to the C-N stretching vibration of the azo compound. The result shows a good linear correlation (R2= 0.9786) against carbofuran concentrations (0.1 - 5 ppm) with a detection limit of 0.452 ppm. Our proposed protocol is insignificantly influenced by various common interferences. Moreover, this method has been successfully validated to determine carbofuran concentrations in rice and soybean with detection limits of 0.446 and 0.520 ppm, respectively.
authors.affiliation: Sensor Research Unit (SRU), Department of Chemistry, Faculty of Science, Chulalongkorn University.
authors.forename: Thanyada
authors.initials: T
authors.lastname: Sukmanee
authors.forename: Kanet
authors.initials: K
authors.lastname: Wongravee
authors.forename: Sanong
authors.initials: S
authors.lastname: Ekgasit
authors.forename: Chuchaat
authors.initials: C
authors.lastname: Thammacharoen
authors.forename: Prompong
authors.initials: P
authors.lastname: Pienpinijtham
mesh_terms: D002235:Carbofuran / Q000032:analysis* / Q000737:chemistry; D005506:Food Contamination / Q000032:analysis*; D057230:Limit of Detection; D012275:Oryza / Q000737:chemistry*; D010573:Pesticide Residues / Q000032:analysis* / Q000737:chemistry; D012834:Silver / Q000737:chemistry; D013025:Glycine max / Q000737:chemistry*; D013059:Spectrum Analysis, Raman; D013997:Time Factors
chemical_list: D010573:Pesticide Residues; D012834:Silver; D002235:Carbofuran