Determination of chloramphenicol in milk by ten chemiluminescent immunoassays: influence of assay format applied $(document).ready(function() { if (!$("html").hasClass("ie8")) { $.ajax({ url: "https://crossmark-cdn.crossref.org/widget/v2.0/widget.js", dataType: "script", cache: true }).done(function() { $(".crossmark-button").addClass("visible"); }); } });

Abstract

Although chloramphenicol (CAP) is banned for treatment of food-producing animals, it is one of the most frequently detected veterinary drugs in animal-derived foods. In this study, 10 chemiluminescent immunoassay formats were developed and evaluated in order to identify the most suitable one for the detection of CAP, with the different combinations of passive coating/covalently-bound, direct/indirect competitive reaction and using polyclonal antibodies (PAb)/monoclonal antibodies (MAb). Among the 10 immunoassay formats, Format 9 using covalently-bound, reverse competitive reaction and anti-CAP PAb exhibited the best sensitivity of 0.0052 μg L⁻¹, which was increased by about 44.2 times when compared with Format 1 using the combination of passive coating and MAb. The milk spiked with different concentrations was detected by the developed immunoassays, and the recoveries ranged from 88% to 94% with the coefficients of variation (CVs) less than 8.5% in Format 9, which were superior to that of other formats with recoveries ranging from 80.0% to 96.0% and CVs less than 12.5%. Hence, the chemiluminescent immunoassay based on covalent bonding, PAb and reverse reaction, enhancing the sensitivity of an immunoassay, can more accurately detect CAP in milk. Moreover, all 10 chemiluminescent immunoassays could screen CAP in the samples as the LC-MS/MS and ELISA kit. Overall, the chemiluminescent immunoassay Format 9 is recommended for the application of detection of trace CAP in milk.