Glyphosate [N-(phosphonomethyl)glycine] has been one of the world's most widely applied herbicides since it came on the market in 1970s under the trade name Roundup. It is used for weed control in agriculture, forestry and gardens, and also on railway embankments. Glyphosate is rapidly adsorbed in soil and degraded to aminomethylphosphonic acid (AMPA) its major metabolite and then transported to groundwater and surfacewater. The permissible level for individual pesticides including glyphosate and AMPA for drinking water is set at the pseudo-zero value of 90%) for analysis of glyphosate and AMPA at low levels. Glyphosate and AMPA derivatized with FMOC then are separated in SunfireTM C18 (50mm x 2.1mm i.d, 3.5µm) column prior to the determination on LC-MS/MS.