In residue analysis, detection of minute quantities of substances in samples of complex nature is a common problem. To specifically isolate an analyte in sufficient quantity, extensive sample pre-treatment is necessary followed by separation and instrumental detection. Low concentrations (ppt or low ppb levels) in veterinary samples require a high degree of clean-up to reduce potential problems in instrumental analysis. One of the widely used solid-phase extraction techniques is immunochromatography.
In immunoaffinity chromatography (IAC) monoclonal or polyclonal antibodies, raised against the analyte are used to selectively bind an analyte in aqueous sample extracts. In this way selective pre-concentration is obtained enabling use of: less complicated sample pre-treatment procedures, less complex analytical equipment, lower limits of detection.
IAC has become a valuable tool in residue analysis and is often used in routine analysis. The specificity of IAC depends on a number of factors including cross-reactivity, aspecific binding on solid support and the conditions during loading and elution. In some applications, a mixture of antibodies is used to broaden the specificity of IAC (multi-immunoaffinity chromatography (MIAC)).
The IAC capacity is dependent upon the amount and quality of antibodies immobilised. Matrix effects is another important factor determining the capacity of a column.
EuroProxima now offers a full range of (multi-) immunoaffinity columns for sample matrix clean-up for Anabolic Steroids, Beta-Agonists, Corticosteroids and Chloramphenicol.