F. Veiga et al., Dynamics of glyphosate and aminomethylphosphonic acid in a forest soil in Galicia, north-west Spain, SCI TOTAL E, 271(1-3), 2001, pp. 135-144
Residues of the herbicide glyphosate (N-phosphonomethylglicine) and its mai
n metabolite, aminomethylphosphonic acid (AMPA), were determined in a fores
t soil in north-west Spain, previously treated with 5 and 8 1 ha(-1) of gly
phosate. Both Products were monitored in the solid and liquid soil phases f
or an 8-week period after the treatment. Soil samples were extracted by KH,
PO,. Concentrated extracts and liquid phase samples were derivatized with 9
-fluorenylmethyl chloroformate (FMOC) before determination by HPLC using an
anion exchange column and spectrofluorometric detection. The treated soil
peaked at 6.9 mug g(-1) of glyphosate, whereas soil water samples peaked at
0.74 mug ml(-1) of glyphosate. One month after the treatment, both glyphos
ate and AMPA concentrations in soil and water samples were almost negligibl
e. AMPA peaked at 0.77 mug ml(-1) in soil water samples. Glyphosate and AMP
A exhibited high vertical mobility in the treated soil, quickly reaching hi
gh concentrations in subsurface horizons where the degradation is slower. (
C) 2001 Elsevier Science B.V. All rights reserved.