title: Immunochemical screening of pesticides (simazine and cypermethrin) in orange oil.
abstract: Pesticide residue analysis in citrus oils is very important for their quality and marketing. This study assessed the reliability and sensitivity of enzyme-linked immunosorbent assays (ELISA) for simazine and cypermethrin screening in orange oil. Simazine was analyzed after extraction of the oil with methanolic phosphate buffer with a limit of quantitation (LOQ) of 40 microg/L for 1-fold and approximately 100 microg/L for 10-fold oils. Due to matrix effects the immunoanalysis of cypermethrin required hexane-acetonitrile partitioning followed by silica solid phase extraction. The method detected levels higher than 0.5 ppm (mg/L). This LOQ is lower than the U.S. EPA tolerance level (0.9 ppm) for cypermethrin in citrus oils. A good correlation (r(2) 0.99) between ELISA and LC-MS/MS was observed for the analysis of both analytes in 1-fold orange oil. Immunochemical screening can be used to reduce instrumental analysis costs by its use in preliminary orange oil screening.
authors.affiliation: Department of Entomology, University of California, Davis, California 95616, USA.
authors.forename: Mikaela
authors.initials: M
authors.lastname: Nichkova
authors.forename: Xun
authors.initials: X
authors.lastname: Fu
authors.forename: Zheng
authors.initials: Z
authors.lastname: Yang
authors.forename: Ping
authors.initials: P
authors.lastname: Zhong
authors.forename: James R
authors.initials: JR
authors.lastname: Sanborn
authors.forename: Dan
authors.initials: D
authors.lastname: Chang
authors.forename: Shirley J
authors.initials: SJ
authors.lastname: Gee
authors.forename: Bruce D
authors.initials: BD
authors.lastname: Hammock
mesh_terms: D002853:Chromatography, Liquid; D004797:Enzyme-Linked Immunosorbent Assay; D006540:Herbicides / Q000032:analysis*; D007306:Insecticides / Q000032:analysis*; D010938:Plant Oils / Q000737:chemistry*; D011722:Pyrethrins / Q000032:analysis*; D012680:Sensitivity and Specificity; D012839:Simazine / Q000032:analysis*; D053719:Tandem Mass Spectrometry
chemical_list: D006540:Herbicides; D007306:Insecticides; D010938:Plant Oils; D011722:Pyrethrins; C017160:cypermethrin; C087245:orange oil; D012839:Simazine