Development of a Magnetic Particle-Based Automated Chemiluminescent Immunoassay for Triasulfuron

• Published in: Journal of agricultural and food chemistry Vol. 42; no. 9; pp. 1914 - 1919
• Main Authors: Schlaeppi, Jean-Marc A, Kessler, Anton, Foery, Werner
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01-09-1994
• Subjects: Agronomy. Soil science and plant productions; ANALISIS CUANTITATIVO; ANALYSE QUANTITATIVE; ANTICORPS MONOCLONAL; ANTICUERPOS MONOCLONALES; Biological and medical sciences; Food industries; Fundamental and applied biological sciences. Psychology; General aspects; HERBICIDAS; HERBICIDE; Methods and techniques; Methods of analysis, processing and quality control, regulation, standards; RESIDU; RESIDUOS; Soil science; TECHNIQUE IMMUNOCHIMIOLUMINESCENTE; TECNICAS INMUNOQUIMIOLUMINISCENTES; Assay; Soils; Monoclonal antibody; Automatic analysis; Herbicide; Immunological method
• ISSN: 0021-8561; 1520-5118
• DOI: 10.1021/jf00045a016

A fully automated immunoassay with high sample throughput for the quantitative analysis of triasulfuron in soil has been developed. The competitive assay was run on the Ciba-Corning ACS: 180 benchtop immunoassay analyzer and used a combination of hapten-bound paramagnetic particles and acridinium ester-labeled monoclonal antibody. Different solid-phase antigens for assay optimization were compared. Three consisted of protein-hapten conjugates covalently linked to primary amine-coated particles, and one corresponded to the chloroethoxy phenylsulfonylurea moiety of triasulfuron with an extended aminopentyl spacer specially designed to improve assay sensitivity and to allow a single step coupling of the hapten to the particles without protein carrier. In the latter assay format, the limits of detection of triasulfuron were 0.02 micrograms/L in aqueous media and 0.05 micrograms/kg in soil. Specificity studies indicated that among several structurally related compounds, cinosulfuron showed 250% cross-reactivity while all other compounds studied showed 3.5%. Quantitative determinations of triasulfuron in soil samples obtained from a field trial were measured by automated immunoassay. They compared favorably with HPLC measurements (correlation coefficient of 0.96). The intra- and interassay coefficients of variation were less than 5 and 11%, respectively