Determination of glyphosate by ion chromatography

An ion chromatography system for the determination of glyphosate was described. Ion chromatograph was carried out by suppressed conductivity detection (DX-100). The eluent contained 9 mmol l-1 Na2CO3 and 4 mmol l-1 NaOH. The detection limit was 0.042 microgram ml-1 (S/N = 3). The relative standard deviation was 1.99% and the correlation coefficient of the calibration curve for area was 0.9995. The linear range was 0.042-100 micrograms ml-1. Common inorganic ion and organic acids did not interfere. The recovery was 96.4-103.2%. The method was simple, rapid, reliable and inexpensive.