title: An updated liquid chromatographic assay for the determination of glyphosate in technical material and formulations.
abstract: An updated liquid chromatographic (LC) method for the determination of glyphosate in technical material and formulations was tested by 7 laboratories. Samples were dissolved in water and injected into an LC system with a C18 guard column, an anion exchange analytical column, and a phosphate buffer mobile phase with 12 to 15% methanol. Detection was by UV absorption at 195 nm or refractive index. Automated injections were made. Calculations were based on peak area comparisons with external standards. The interlaboratory study analyzed 6 matched pairs of 3 glyphosate technical materials and 3 glyphosate formulations. The matched pair results were analyzed by using the AOAC spreadsheet and Youden's matched pair calculations. Coefficients of variation for the 6 samples ranged from 0.46 to 0.85%.
authors: walter.k.gavlick@monsanto.com
authors: Walter K
authors: WK
authors: Gavlick
authors: David F
authors: DF
authors: Tomkins
mesh_terms: D002626:Chemistry, Pharmaceutical; D002853:Chromatography, Liquid / Q000379:methods*; D005998:Glycine / Q000031:analogs & derivatives* / Q000032:analysis; D006540:Herbicides / Q000032:analysis*; D000097797:Glyphosate
chemical_list: D005998:Glycine; D006540:Herbicides; D000097797:Glyphosate