The mono-isopropylamine salt of glyphosate was selectively determined directly in industrial and commercial formulations using flow injection analysis with tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection without the need for separation. Glyphosate and its mono-isopropylamine salt furnished detection limits of 7x10 - 9 and 3.5x10 - 1 0 M and relative standard deviations of 0.4% at 1x10 - 7 M and 0.8% at 5x10 - 8 M, respectively. The methodology is robust and reliable with samples subjected only to aqueous dilution prior to analysis.