title: Determination of aflatoxin M1 using a dialysis-based immunoaffinity sample pretreatment system coupled on-line to liquid chromatography. Reusable immunoaffinity columns.
abstract: A liquid chromatographic column-switching system containing a dialysis unit and an anti-aflatoxin immunoaffinity precolumn (immuno precolumn) is described for the automated determination of aflatoxin M1 in milk samples. Both a flat membrane dialysis unit working according to the flowing donor-flowing acceptor principle and a laboratory made hollow-fibre dialysis unit working according to the stagnant donor-flowing acceptor principle were evaluated. The hollow-fibre unit is superior with respect to repeatability (3% relative standard deviation) and detection limit (10 ng/l for aflatoxin M1 in milk), in spite of the fact that the overall recovery is only 6%. Interfering compounds, which would destroy the activity of the immuno precolumn, are efficiently removed from the system by the dialysis step; a single immuno precolumn can then be used for over 70 milk analyses. No decrease in the performance of either the immuno precolumn or the hollow-fibre dialysis unit is observed.
authors.affiliation: Department of Analytical Chemistry, Free University, Amsterdam, Netherlands.
authors.forename: A
authors.initials: A
authors.lastname: Farjam
authors.forename: N C
authors.initials: NC
authors.lastname: van de Merbel
authors.forename: A A
authors.initials: AA
authors.lastname: Nieman
authors.forename: H
authors.initials: H
authors.lastname: Lingeman
authors.forename: U A
authors.initials: UA
authors.lastname: Brinkman
mesh_terms: D016607:Aflatoxin M1 / Q000032:analysis*; D000818:Animals; D002846:Chromatography, Affinity / Q000295:instrumentation / Q000379:methods*; D002853:Chromatography, Liquid / Q000379:methods*; D008892:Milk / Q000032:analysis
chemical_list: D016607:Aflatoxin M1