Persistence and bioaccumulation of oxyfluorfen residues in onion

Abstract

A field study was conducted to determine persistence and bioaccumulation of oxyflorfen residues in onion crop at two growth stages. Oxyfluorfen (23.5% EC) was sprayed at 250 and 500 g ai/ha on the crop (variety, N53). Mature onion and soil samples were collected at harvest. Green onion were collected at 55 days from each treated and control plot and analyzed for oxyfluorfen residues by a validated high-performance liquid chromatography method with an accepted recovery of 78-92% at the minimum detectable concentration of 0.003 microg g(-1). Analysis showed 0.015 and 0.005 microg g(-1) residues of oxyfluorfen at 250 g a.i. ha(-1) rate in green and mature onion samples, respectively; however, at 500 g a.i.ha(-1) rates, 0.025 and 0.011 microg g(-1) of oxyfluorfen residues were detected in green and mature onion samples, respectively. Soil samples collected at harvest showed 0.003 and 0.003 microg g(-1) of oxyfluorfen residues at the doses 250 and 500 g a.i. ha(-1), respectively. From the study, a pre-harvest interval of 118 days for onion crop after the herbicide application is suggested.

Removal of oxyfluorfen from spiked soils using electrokinetic soil flushing with the surrounding arrangements of electrodes

“…Evaporation and photolysis can help to understand this decrease, according to the literature (Alister et al, 2009;Das et al, 2003;Mantzos et al, 2014;Sondhia, 2010;Sondhia and Dixit, 2010). In this point, it is worth to take in mind that in comparing the vapor pressure of oxyfluorfen (0.026 mPa at 25ºC) with other less volatile pesticide like chlorsulfuron (3×10 -6 mPa at 25ºC) evaporation of oxyfluorfen can be even 10000 times higher.…”

“…Microbial degradation is not a major factor to be accounted for in this herbicide. The half-life in soil approximately ranges from 30 to 56 days, and the organic matter content of the soil seems to influence the oxyfluorfen persistence and activity (Sondhia, 2010;Sondhia and Dixit, 2010). Finally, regarding its transport properties, it has been observed (Mantzos et al, 2014) that oxyfluorfen hardly moves into silty clay soil and exhibits low run-off potential.…”

Dissipation kinetics of glyphosate in tea and tea-field under northwestern mid-hill conditions of India

“…Data on the rate of degradation are extremely important as they permit prediction of the levels likely to remain in the soil and allow assessment of the risk associated with exposure, [8][9][10][11][12] and contamination of tea leaves. On degradation, glyphosate yields, AMPA (amino methyl phosphonic acid) a major metabolite of glyphosate which finally degrades and mineralizes to CO 2 .…”

Simultaneous analysis of herbicides pendimethalin, oxyfluorfen, imazethapyr and quizalofop-p-ethyl by LC–MS/MS and safety evaluation of their harvest time residues in peanut (Arachis hypogaea L.)

“…Different chromatographic methods, such as liquid chromatography (LC) (Maldaner et al 2008;Sondhia, 2010;Shah et al 2011), capillary electrophoresis (Han et al 2008), gas chromatography (GC) (Engebretson et al 2001;Fenoll et al 2008;Hu et al 2010) and enzyme-linked immunoassay (Steinheimer and Scoggin, 1998;Zeng et al 2006) have been used till date for the determination of these herbicide residues in different matrices. In comparison with conventional techniques of GC and LC, LC hyphenated with tandem mass spectrometry (LC-MS/MS) is a prevailing technique in pesticide residues analysis, as the number of polar and non-GCamenable pesticides used in oilseeds is increasing.…”