title: A solution for isomerization of pyrethroid insecticides in gas chromatography.
abstract: Isomerization of pyrethroid insecticides was observed during extraction and gas chromatography (GC) analysis. An improvement in sensitivity was noted for pyrethroids in sediment extracts in comparison to pure solvent. Stability of pyrethroids using different solvents and analyte additives were investigated, and GC injection conditions were optimized. Polar solvents enhanced pyrethroid isomerization, while hexane was the best choice as an analytical solvent. Acetic acid was used successfully as an isomer-stabilizing agent for GC analysis of pyrethroids. Acidified (0.1% acetic acid) hexane prevented pyrethroid isomerization, increased peak intensity up to 1.9 times, and calibration curve linearity (relative standard deviation for response factors) 0.8-12.5 times compared to hexane alone.
authors.affiliation: Fisheries and Illinois Aquaculture Center & Department of Zoology, 171 Life Science II, Southern Illinois University, Carbondale, IL 62901, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: You
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Lydy
mesh_terms: D002849:Chromatography, Gas / Q000379:methods*; D007306:Insecticides / Q000737:chemistry*; D007536:Isomerism; D011722:Pyrethrins / Q000737:chemistry*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012997:Solvents
chemical_list: D007306:Insecticides; D011722:Pyrethrins; D012997:Solvents