Applicability of metal oxides as selective extractant of glyphosate for ion chromatography with a conductometric detector

Abstract

The applicability of metal oxide as a selective extractant for ionic compounds was investigated to establish an easy and selective determination method using ion chromatography coupled with conductivity detection. The extraction properties of zirconia and titania for glyphosate (N-(phosphonomethyl)glycine, GLYP) as an analyte were evaluated. Although it has been recognized that both zirconia and titania have high affinity for phosphate compounds, the leakage of GLYP from a solid-phase extraction cartridge packed with the titania used in this study was observed. On the other hand, zirconia could perform an effective extraction of GLYP with high retention ability. Also, a solid-phase extraction cartridge packed with 35 mg of the zirconia was able to certainly entrap GLYP in spite of a sample load of 250 mL. GLYP entrapped on the zirconia could be eluted with 2 mL of 0.4 M sodium hydroxide as an eluent. GLYP in the effluent could be sensitively detected by ion chromatography with conductometric detection using neutralization employing a suppressor module. The proposed method was applied to the determination of GLYP in urban river water samples. The limit of quantification was around 0.001 mg L -1 for GLYP. © 2013 The Japan Society for Analytical Chemistry.