Extraction of [14C]glyphosate from Saskatchewan soils

The extraction of 14 C from air-dried samples of three soil fortified 14 days previously with [ 14 C]-glyphosate was compared using 10 different solvent systems and an extended-shaking procedure. 14 C recoveries exceeding 73% were reproducibly achieved with 0.35 M H 3 PO 4 (and 0.09 M with respect to CaCl 2 ), 0.1 M NaOH, and 0.5 M NH 4 OH []