Rapid determination of clenbuterol in urine by a competitive bead immunoassay based on Luminex technology.

A new competitive bead immunoassay (CBIA) based on Luminex technology for detecting clenbuterol in urine was reported. The carboxylated fluorescent beads were directly coated with clenbuterol derivatives without carrier protein spacer. Clenbuterol antibody was biotinylated, which was used for clenbuterol detection in combination with the functionalized bead and streptavidin-phycoerythrin (SAPE).

Development of an indirect enzyme-linked immunosorbent assay for the organophosphorus pesticide paraoxon-methyl.

In the present study, the synthesis of hapten for the organophosphorus (OP) pesticide paraoxon-methyl was developed, with a spacer arm (aminocarboxylic acid) attached at the aromatic ring. It was conjugated to bovine serum albumin (BSA) for use as an immunogen and to ovalbumin (OVA) for coating antigen for ELISA testing. Rabbits were immunized with the immunogen and two polyclonal antisera were produced and screened against the coating antigen using competitive indirect enzyme-linked immunosorbent assay (ELISA).

Development of an immunochromatographic assay for rapid detection of 1-Aminohydantoin in urine specimens.

A rapid immunochromatographic assay was developed and validated for detection of 1-aminohydantoin (AHD) in urine specimens. Colloidal gold-labeled polyclonal antibody specific to AHD derivative was used as the marker; based on the competitive reactivity theory, the metabolite of nitrofurantoin after derivatization with benzaldehyde would compete with carboxyphenyl AHD derivative-conjugated ovalbumin. The test strip could efficaciously detect the novel analyte with a visual detection limit of 10 ng mL(-1) and high specificity.

Rapid determination of chloramphenicol residues in aquaculture tissues by immunochromatographic assay.

An immunochromatographic assay was developed to detect chloramphenicol (CAP) residues in aquaculture tissues. The limit of detection (LOD) was 10 ng g(-1) for detecting CAP spiked in the aquaculture tissues. The results were confirmed by liquid chromatography tandem mass spectrometry (LC/MS/MS) and indicated that there was a good agreement between the two methods.

Determination of medroxyprogesterone acetate residues by CE immunoassay with chemiluminescence detection.

A rapid and simple method is developed for the determination of medroxyprogesterone acetate (MPA) by CE immunoassay with chemiluminescence (CL). This method is based on the competitive reactions between horseradish peroxidase (HRP)-labeled MPA (MPA-HRP) and free MPA with anti-MPA antiserum. The influencing factors on the electrophoresis and CL detection were studied completely and the optimal conditions of separation and determination were obtained.

Determination of hexoestrol residues in animal tissues based on enzyme-linked immunosorbent assay and comparison with liquid chromatography-tandem mass spectrometry.

A competitive enzyme-linked immunosorbent assay (ELISA) was developed for the quantitative detection of the hexoestrol (HES). Polyclonal rabbit antisera, raised against protein conjugate hexoestrol-mono-carboxyl-propyl-ethyl-bovine-serum-albumin (HES-MCPE-BSA), were utilized in immobilized antibody-based and competitive immunoassays. Assay conditions, including concentrations of antisera and Horseradish peroxidase (HRP)-HES were optimized.

Development of a faster determination of 10 anabolic steroids residues in animal muscle tissues by liquid chromatography tandem mass spectrometry.

A method had been developed for determination of residues of 10 anabolic steroids (ASs) in animal muscle tissues by liquid chromatography tandem mass spectrometry (LC/MS/MS). After enzymolysis, the sample was extracted with tert-butyl methyl ether, cleaned up through reverse solid-phase extraction and further determined by LC/MS/MS under multiple reaction monitoring (MRM) mode. The limits of detection (LOD) of LC/MS/MS method used for testing epitestosterone (ETS), nandrolone (17 beta-NT), 17 alpha-methyl-testosterone (MTS), testosterone 17-propionate (PTS), medroxyprogesterone (MED), progesterone (PG), estrone (ESN), 17 beta-estradiol (17 beta-ES), 17alpha-ethynylestradiol (EES) and estriol (EST) in animal muscle ranged from 0.