title: Rapid and direct determination of glyphosate, glufosinate, and aminophosphonic acid by online preconcentration CE with contactless conductivity detection.
abstract: Rapid and direct online preconcentration followed by CE with capacitively coupled contactless conductivity detection (CE-C(4)D) is evaluated as a new approach for the determination of glyphosate, glufosinate (GLUF), and aminophosphonic acid (AMPA) in drinking water. Two online preconcentration techniques, namely large volume sample stacking without polarity switching and field-enhanced sample injection, coupled with CE-C(4)D were successfully developed and optimized. Under optimized conditions, LODs in the range of 0.01-0.1 microM (1.7-11.1 microg/L) and sensitivity enhancements of 48- to 53-fold were achieved with the large volume sample stacking-CE-C(4)D method. By performing the field-enhanced sample injection-CE-C(4)D procedure, excellent LODs down to 0.0005-0.02 microM (0.1-2.2 microg/L) as well as sensitivity enhancements of up to 245- to 1002-fold were obtained. Both techniques showed satisfactory reproducibility with RSDs of peak height of better than 10%. The newly established approaches were successfully applied to the analysis of glyphosate, glufosinate, and aminophosphonic acid in spiked tap drinking water.
authors.affiliation: Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, Skudai, Johor, Malaysia.
authors.forename: Hong Heng
authors.initials: HH
authors.lastname: See
authors.forename: Peter C
authors.initials: PC
authors.lastname: Hauser
authors.forename: Wan Aini Wan
authors.initials: WA
authors.lastname: Ibrahim
authors.forename: Mohd Marsin
authors.initials: MM
authors.lastname: Sanagi
mesh_terms: D000613:Aminobutyrates / Q000032:analysis*; D004553:Electric Conductivity; D019075:Electrophoresis, Capillary / Q000379:methods*; D005998:Glycine / Q000031:analogs & derivatives* / Q000032:analysis; D006540:Herbicides / Q000032:analysis; D009862:Online Systems; D063065:Organophosphonates / Q000032:analysis*; D015203:Reproducibility of Results; D014867:Water / Q000737:chemistry; D014881:Water Supply; D000097797:Glyphosate
chemical_list: D000613:Aminobutyrates; D005998:Glycine; D006540:Herbicides; D063065:Organophosphonates; D014867:Water; D000097797:Glyphosate; C003121:phosphinothricin