title: Quantification of 2,4-dichlorophenoxyacetic acid in oranges and mandarins by chemiluminescent ELISA.
abstract: Direct competitive enzyme-linked immunosorbent assay (ELISA) for 2,4-dichlorophenoxyacetic acid (2,4-D) was developed. Varying the concentrations of monoclonal anti-2,4-D-antibody and the conjugate of soybean peroxidase and 2,4-D the conditions of ELISA performance were optimised. The chemiluminescent method based on peroxidase-catalysed oxidation of luminol was applied to measure the enzyme activity of the conjugate. A mixture of 3-(10'-phenothiazinyl)propane-1-sulfonate and 4-morpholinopyridine was used as potent enhancer of chemiluminescence signal. It was shown that the values of the lower detection limit, IC50 and the working range were 1.5, 64.0, and 6.5-545ng/mL, respectively. The recovery values of CL-ELISA from 10 spiked samples of oranges (n=5) and mandarins (n=5) cultivated in green house without use of 2,4-D and containing different 2,4-D concentrations (10-300ng/mL) were ranged from 92% to 104% that indicated on the absence of matrix effect for the fruit extracts of interest. Determination of 2,4-D in peel of five oranges and five mandarins purchased from stores in Vietnam showed that 2,4-D content in oranges fruits (79-104μg/kg) was significantly higher than that in mandarins (1.66-2.82μg/kg).
authors.affiliation: Faculty of Chemistry, M.V. Lomonosov Moscow State University, 119991 Moscow, Russia.
authors.forename: Marina M
authors.initials: MM
authors.lastname: Vdovenko
authors.forename: Alexandra S
authors.initials: AS
authors.lastname: Stepanova
authors.forename: Sergei A
authors.initials: SA
authors.lastname: Eremin
authors.forename: Nguyen
authors.initials: N
authors.lastname: Van Cuong
authors.forename: Natalia A
authors.initials: NA
authors.lastname: Uskova
authors.forename: Ivan
authors.initials: I
authors.lastname: Yu Sakharov
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000032:analysis*; D032084:Citrus sinensis / Q000737:chemistry*; D004350:Drug Residues / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005638:Fruit / Q000737:chemistry*; D006540:Herbicides / Q000032:analysis*; D057230:Limit of Detection; D008163:Luminescent Measurements / Q000379:methods*
chemical_list: D006540:Herbicides; D015084:2,4-Dichlorophenoxyacetic Acid