Enzyme-linked immunosorbent assay and colloidal gold immunoassay for sulphamethazine residues in edible animal foods: investigation of the effects of the analytical conditions and the sample matrix on assay performance

Abstract

To determine sulphamethazine (SMZ) residues in edible animal foods (pig muscle, chicken muscle, egg, fish, milk and liver), a competitive direct enzyme-linked immunosorbent assay (ELISA) and a colloidal gold immunoassay were established. The limits of detection of the ELISA and the colloidal gold immunoassay were 0.02 and 0.5 microg kg(-1), respectively. The specificity of the ELISA developed to the SMZ was high according to the results of cross-reactivity testing with 14 kinds of sulphonamides. To obtain a more sensitive immunoassay, buffer solution (30 mmol L(-1) phosphate-buffered saline with 0.05% Tween 20, pH 8.5) was optimized through the whole test procedure. A simple and efficient extraction method for the rapid detection of SMZ residues in foods was developed, with recoveries between 74 and 117.5%. Matrix effects can be avoided by 1:10 dilution of pig muscle, chicken muscle, egg, fish, milk and liver with optimal buffer. The detection limit of SMZ was 5 microg kg(-1) in liver and 2 microg kg(-1) in the other five samples. For the validation of the ELISA tests, sample extracts were analysed by ELISA and high-performance liquid chromatography. The results obtained by these two methods showed a good correlation (r(2)) which was greater than 0.9. The colloidal gold immunoassay presented in this assay was successfully applied to determine SMZ in pig muscle, milk and fish below or equal to the maximum residue level (20 microg kg(-1)).

Sensitive enzyme‐linked immunosorbent assay and gold nanoparticle immunochromatocgraphic strip for rapid detecting chloramphenicol in food

“…Due to the honey and milk sample contain protein, sugar and fat, might influence the antibody–antigen binding (Apollonio, Whittall, Pianca, Kyd, & Maher, ; Radoi, Targa, Prieto‐Simon, & Marty, ). These matrix effects may decrease the OD value and the sensitivity of dcELISA (Wang, Wang, Zhang, Liu, & Zhang, ). Therefore, this study referred to the previous report which using PBS‐BSA‐Tween as sample dilution buffer to prevent the matrix effects (Chen, Wang, Ferreri, Su, & Han, ).…”

“…Due to the honey and milk sample contain protein, sugar and fat, might influence the antibody-antigen binding (Apollonio, Whittall, Pianca, Kyd, & Maher, 2007;Radoi, Targa, Prieto-Simon, & Marty, 2008). These matrix effects may decrease the OD value and the sensitivity of dcELISA (Wang, Wang, Zhang, Liu, & Zhang, 2008).…”

Comparison of Immobilization Modes in pH‐Sensitive Phase Separation Immunoassay

“…1,2 Generally, immunoassays can be divided into two categories, heterogeneous and homogeneous. Heterogeneous assays such as enzyme-linked immunosorbent assays (ELISA), 3 represent selective and sensitive analytical procedures. However, ELISA requires extensive sample handling and a long analysis time.…”

Síntesis De Inmunorreactivos Para La Determinación De Sulfonamidas Y Tetraciclinas en Alimentos

“…Sin embargo, el resto de inmunorreactivos necesarios los prepararon siguiendo el procedimiento descrito por Dixon et al 75 utilizando STZ, SMZ y SDM como sulfonamidas base. Siguiendo esta misma estrategia varios autores describieron la obtención de anticuerpos policlonales para distintas sulfonamidas (SMZ, STZ) 76,77,78,79,80,81 . Utilizando glutaraldehído como cross-linker, se ha descrito la obtención de anticuerpos monoclonales y policlonales para sulfametazina, preparando el inmunógeno por acoplamiento directo de SMZ a seroalbúmina bovina (BSA) 75 .…”

“…Se observa que el mayor número de inmunoensayos desarrollados corresponden a sulfametazina 77,79,81,106 , debido a las reacciones alérgicas o tóxicas y a su uso generalizado. Asimismo, se han descrito inmunoensayos sensibles para SMZ con un límite de detección por debajo de 10 μg/L.…”