Development of a Monoclonal Antibody-Based cELISA for the Analysis of Sulfadimethoxine. 2. Evaluation of Rapid Extraction Methods and Implications for the Analysis of Incurred Residues in Chicken Live

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• 作者：Mark T. Muldoon ; Sandra A. Buckley ; Sudhir S. Deshpande ; Carol K. Holtzapple ; Ross C. Beier ; and Larry H. Stanker
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2000
• 出版时间：February 2000
• 年：2000
• 卷：48
• 期：2
• 页码：545 - 550
• 全文大小：68K
• 年卷期：v.48,no.2(February 2000)
• ISSN：1520-5118

文摘

Several rapid extraction methods were evaluated for use with a monoclonal antibody-basedcompetitive inhibition ELISA (cELISA) to detect sulfadimethoxine (SDM) in chicken liver tissue.These methods included extraction of the samples with (1) aqueous buffer with or withoutultrafiltration, (2) acetonitrile/water, (3) methanol/water, or (4) acetone. The organic extractionmethods were evaluated with or without solvent evaporation prior to dilution into assay buffer forthe cELISA. The aqueous-based extraction methods were compatible with the cELISA. However, ofthe organic extraction methods, only the acetone liver extract with solvent evaporation prior toanalysis was compatible with the cELISA. The cELISA method coupled to aqueous- or acetone-based sample extraction as well as an HPLC method was evaluated for the analysis of chicken livertissues fortified with SDM at levels from 0.2 to 0.025 ppm. Mean SDM recoveries for the HPLCmethod and for the cELISA method using samples prepared by aqueous extraction, aqueousextraction and ultrafiltration, or acetone extraction, evaporation, and reconstitution were 68.9, 95.7,60.1, and 52.5%, respectively. For the analysis of samples obtained from an SDM incurred residuestudy, HPLC and cELISA analysis of the same organic extract gave results that were highlycorrelated (R² = 0.976; p < 0.0001). However, results obtained from the analysis of aqueous extractsby cELISA did not correlate well with those obtained by HPLC (R² = 0.61, p > 0.0006). This wasattributed to the coextraction of cross-reactive SDM-related residues that were not quantified bythe HPLC method. The presence of these residues should be considered during data interpretationwhen ELISA methods coupled with rapid aqueous extraction of samples are used in SDM residuemonitoring programs.Keywords: Sulfadimethoxine; immunoassay; extraction methods; food safety