Preparation of artificial antigen and egg yolk-derived immunoglobulin (IgY) of florfenicol amine for ELISA assay.

To investigate the feasibility of IgY technology for the immune detection of haptens, a specific egg yolk antibody (IgY) has been developed in order to detect the florfenicol amine (FFA) residues. FFA was conjugated to bovine serum albumin (BSA) by glutaraldehyde (GA) and the conjugate was used to immunize laying chickens. Anti-FFA IgY antibody was purified by PEG-6000 precipitation and identified by SDS-PAGE. The titer of anti-FFA IgY antibody reached a peak of 1:128,000 after three booster injections. Checkerboard titration showed that a 1:800 dilution of anti-FFA IgY could give an optical density (OD) at around 1.0 at 10 µg/mL FFA-OVA coating concentration. An indirect competitive enzyme-linked immunosorbent assay (icELISA) using specific anti-FFA IgY showed that the IC50 value of anti-FFA IgY was 12.30 ng/mL and the regression curve equation was y = -13.71x + 64.95 (R (2) = 0.945). The strategy of developing anti-hapten IgY antibody is that it may be further used as a new reagent for an immunoassay of hapten residues.

Simultaneous analysis of thiabendazole, carbendazim and 2-aminobenzimidazole in concentrated fruit juices by liquid chromatography after a single mix-mode solid-phase extraction cleanup.

A method using liquid chromatography and a single mix-mode solid-phase extraction cleanup for the simultaneous analysis of thiabendazole [2-(1,3-thiazol-4-yl)-1H-benzoimidazole], carbendazim [(methyl N-(1H-benzoimidazol-2-yl)-carbamate)] and 2-aminobenzimidazole (1H-benzimidazol-2-amine) in concentrated fruit juices is described. The three fungicides were isolated from the samples and concentrated by solid-phase extraction on Oasis MCX cartridges. The determination was performed by liquid chromatography with a diode array, detecting at 288 nm. In this method, the average recoveries from blank control juice samples spiked in a concentration range of 0.01-0.10 mg/kg were in the range of 81-95%, with relative standard deviations below 8%. Detection limits and limits of quantification were 4 micro g/kg and 10 micro g/kg, respectively, for each fungicide. Real juice samples were analyzed by the proposed method. The results were compared to those from liquid chromatography-tandem mass spectrometry.