Rapid enzyme immunoassays for the detection of carbaryl and methoprene in grains.
In order for grain handlers and traders to reliably estimate residues of grain protectants in the field, antibody-based rapid tests were developed for carbaryl (1-naphthyl methylcarbamate) and methoprene [isopropyl (E,E)-(RS)-11-methoxy-3,7,11-trimethyldodeca-2,4-dienoate]. To complement the rapid analysis, a simple and rapid extraction technique was developed. In these tests, a pesticide-containing methanol extract of the grain sample and an enzyme-labeled component are added to precoated strips. After a brief incubation, the strips are washed and a substrate/chromogen for the enzyme is added. The color developed is stopped by acidification and the results are read either by eye or in a portable field photometer. The overall test time is under 20 minutes. For carbaryl, the test had a limit of detection of 4.5 ppb (1.1 ppm in grain), while the methoprene test had a limit of detection of 4 ppb (1 ppm in grain) based on the lower datum point, which is 15% inhibition, in the standard curves. Both assays can be used as a screening test for carbaryl and methoprene in animal feed grains.
Wang
Shuo
S
Department of Agricultural Chemistry and Soil Science, The University of Sydney, NSW, Australia. s.wang@agec.usyd.edu.au
Allan
Robin D
RD
Hill
Amanda S
AS
Kennedy
Ivan R
IR
D001315:Australia; D012721:Carbaryl / Q000032:analysis*; D002523:Edible Grain; D007124:Immunoenzyme Techniques / Q000379:methods*; D008726:Methoprene / Q000032:analysis*; D010573:Pesticide Residues / Q000032:analysis*; D012680:Sensitivity and Specificity
D010573:Pesticide Residues; D008726:Methoprene; D012721:Carbaryl