title: Detection of melamine in feed using liquid-liquid extraction treatment combined with surface-enhanced Raman scattering spectroscopy.
abstract: A rapid, selective, and sensitive method to determine the melamine content in animal feeds was developed using surface-enhanced Raman scattering spectroscopy on aggregated 55 nm Au nanoparticles with liquid-liquid extraction sample preparation. Butyl alcohol was used as the initial extraction solvent, and liquid-liquid extraction was performed twice using HCl (pH 3-4) and 6:1 (v/v) n-butyl alcohol/ethyl acetate. The intensity of the matrix-based peak at 731 cm⁻¹ was set at 100 as a basis for the feeds, and the peak at 707 cm-1 was the characteristic peak of melamine used in the calculations. Sufficient linearity was obtained in the range 2-10 µg·g⁻¹ (R² = 0.991). Limits of detection and quantification in the feeds were 0.5 and 2 µg·g⁻¹, respectively. The recovery rates were 82.5-90.2% with coefficients of variation below 4.02%. This new protocol could be easily developed for the routine monitoring of on-site feed quality and market surveillance.
authors.affiliation: Institute of Quality Standards and Testing Technologies for Agro-products, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Cheng
authors.affiliation: Institute of Quality Standards and Testing Technologies for Agro-products, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Shi
authors.initials: S
authors.lastname: Wang
authors.affiliation: Institute of Quality Standards and Testing Technologies for Agro-products, Chinese Academy of Agricultural Sciences, Beijing, China.
authors.forename: Xiao-Ou
authors.initials: XO
authors.lastname: Su
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D006046:Gold / Q000737:chemistry; D059625:Liquid-Liquid Extraction / Q000379:methods*; D053768:Metal Nanoparticles; D013059:Spectrum Analysis, Raman / Q000379:methods*; D013499:Surface Properties; D014227:Triazines / Q000032:analysis*
chemical_list: D014227:Triazines; D006046:Gold; C011907:melamine