Validation of an enzyme-linked immunosorbent assay for detecting sulfonamides in feed resources.
An enzyme-linked immunosorbent assay (ELISA) to screen sulfadiazine and sulfamethazine residues in feeds has been developed and validated according to Commission Decision 2002/657/EC criteria. Sulfonamides are easily extracted with a 95:5 acetonitrile/water mixture, obtaining recoveries between 80 and 100%. Accuracy, precision, selectivity, robustness, limit of detection (LOD), and detection capability (CCbeta) of the assay have been assessed during the validation process. LOD values in pig feed samples were 0.2 microg/g for sulfadiazine and 0.04 microg/g for sulfamethazine without any sample treatment other than extraction, dilution with the assay buffer, and filtering of the resulting solution. Furthermore, a new strategy for the determination of CCbeta in an ELISA screening method is proposed; this gave CCbeta values of 0.8 microg/g for sulfadiazine and 0.1 microg/g for sulfamethazine. Besides sulfadiazine and sulfamethazine, other sulfonamides can be detected with this immunoassay; this has been verified calculating their LOD values and cross-reactivities. Finally, real feed samples were analyzed with the ELISA methodology and a previously developed liquid chromatography (LC) method, and results confirmed the utility of this new immunoassay for screening purposes.
Jiménez
Vanesa
V
Department of Analytical Chemistry, Universitat de Barcelona (UB), Martí i Franquès 1-11, 08028 Barcelona, Spain.
Adrian
Javier
J
Guiteras
Jacinto
J
Marco
Maria-Pilar
MP
Companyó
Ramon
R
D000821:Animal Feed / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D057230:Limit of Detection; D013449:Sulfonamides / Q000032:analysis*
D013449:Sulfonamides