Residue levels of pyrethrins and piperonyl butoxide in soil and runoff water.
Simultaneous analysis of pyrethrins (Py-I and Py-II) and piperonyl butoxide (PBO) in soil and runoff water samples following field application of a new pyrethrum formulation containing pyrethrins (Py's) and PBO is described. Residues of total Py's and PBO were extracted from soil samples using hexane-acetone (9:1). A solid phase extraction (SPE) column containing C18-octadecyl bonded silica was used to separate Py's and PBO residues from runoff water. Residues in soil and water were quantitated by high performance liquid chromatography (HPLC) equipped with C18-column and a UV detector. Concentration of Py-II in soil was 100 times higher than that of Py-I 1 h following treatment and 9.6 times higher than Py-I in runoff surface water 11 days following treatment. Results indicated that Py's are non-persistent in soil (even though lipophillic) and water when applied at the recommended rate of 6 lbs (5.31 g A.I.) per acre. There was a consistent decrease in total Py's residues as time after spraying increased. Py's residues in soil decreased from 0.91 to 0.11 ppm 4 days following treatment and one month after treatment only 0.002 ppm were detected. The highest concentration of Py's in runoff water was 36.09 ng/liter following the first rainfall (11 days following treatment). PBO initial residues detected in soil samples were low (0.84 microgram/g soil) while no residues of PBO were detected in runoff water.
Antonious
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GF
Kentucky State University, Department of Plant and Soil Science, Atwood Research Facility, Frankfort 40601, USA.
Byers
M E
ME
Kerst
W C
WC
D005618:Fresh Water / Q000032:analysis; D007306:Insecticides / Q000032:analysis; D010573:Pesticide Residues / Q000032:analysis*; D010574:Pesticide Synergists / Q000032:analysis; D010882:Piperonyl Butoxide / Q000031:analogs & derivatives / Q000032:analysis*; D011722:Pyrethrins / Q000032:analysis*; D011891:Rain; D012989:Soil Pollutants / Q000032:analysis*; D014873:Water Pollutants / Q000032:analysis*
D007306:Insecticides; D010573:Pesticide Residues; D010574:Pesticide Synergists; D011722:Pyrethrins; D012989:Soil Pollutants; D014873:Water Pollutants; D010882:Piperonyl Butoxide