Application of a monoclonal-based immunoassay for the determination of imazalil in fruit juices.
A monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) was developed for the quantification of imazalil [(RS)-1-(beta-allyloxy-2,4-dichlorophenylethyl)imidazole] in apple, tomato and orange juice samples. From an imazalil hapten, which mimics the analyte structure, several monoclonal antibodies were obtained. An ELISA in the conjugate-coated format was developed and optimized using the antibody showing the highest sensitivity. For standards, the detection limit of the ELISA was 0.2 nM (0.06 ng ml(-1)), with an I(50) value of 1.6 nM (0.5 ng ml(-1)). The study of the influence of matrices on assay reliability indicated that the ELISA could determine imazalil in fruit juices at the low ng ml(-1) level simply by diluting the sample, without any clean-up or concentration step. Recovery and precision of the method were evaluated by spiking juice samples with imazalil in the 10-500 ng ml(-1) range. The mean recovery from fruit juices was 97% and the mean coefficient of variation was approximately 20%. In addition to being precise and accurate, the method has proved to be simple and sensitive, with a quantification limit well below the maximum residue limits for imazalil in these matrices.
Moreno
María-José
MJ
Instituto de Investigación e Innovación en Bioingeniería, Universidad Politécnica de Valencia, Camino de Veras/n, Edificio 7F, 5a planta, 46022 Valencia, Spain.
Plana
Emma
E
Montoya
Angel
A
Caputo
Pasquale
P
Manclús
Juan J
JJ
D000911:Antibodies, Monoclonal; D001628:Beverages / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D005638:Fruit / Q000737:chemistry*; D005659:Fungicides, Industrial / Q000032:analysis*; D007093:Imidazoles / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*
D000911:Antibodies, Monoclonal; D005659:Fungicides, Industrial; D007093:Imidazoles; D010573:Pesticide Residues; C017435:enilconazole