Rapid and direct determination of glyphosate, glufosinate, and aminophosphonic acid by online preconcentration CE with contactless conductivity detection

• Main Authors: See, Hong Heng, Hauser, Peter C., Wan Ibrahim, Wan Aini, Sanagi, Mohd. Marsin
• Format: Article
• Published: Wiley-VCH Verlag GmbH & Co. KGaA. 2010
• Subjects: QD Chemistry
• Online Access: http://eprints.utm.my/id/eprint/26636/; http://dx.doi.org/10.1002/elps.200900380

Rapid and direct online preconcentration followed by CE with capacitively coupled contactless conductivity detection (CE-C4D) 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-C4D were successfully developed and optimized. Under optimized conditions, LODs in the range of 0.01–0.1 μM (1.7–11.1 μg/L) and sensitivity enhancements of 48- to 53-fold were achieved with the large volume sample stacking-CE-C4D method. By performing the field-enhanced sample injection-CE-C4D procedure, excellent LODs down to 0.0005–0.02 µM (0.1–2.2 µg/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.