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International Journal of Environment Science and Technology
Center for Environment and Energy Research and Studies (CEERS)
ISSN: 1735-1472 EISSN: 1735-1472
Vol. 12, No. 8, 2015, pp. 2475-2484
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Bioline Code: st15233
Full paper language: English
Document type: Research Article
Document available free of charge
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International Journal of Environment Science and Technology, Vol. 12, No. 8, 2015, pp. 2475-2484
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Dissipation kinetics and leaching of cyazofamid fungicide in texturally different agricultural soils
Singh, N. & Tandon, S.
Abstract
Dissipation and leaching studies of cyazofamid
in two texturally different soils of Tarai region of India at
two fortification levels (100 and 200 g a.i. ha-1
) were
carried out for monitoring residual toxicity and groundwater
contamination. Soil was extracted with acetone :
methanol (5:1 v/v) followed by cleanup with florisil SPE.
Separation was achieved by RP-HPLC on a Discovery®
C-18 column using mobile phase acetonitrile: water (60:40
v/v) and detection at 279 nm. Degradation pattern indicated
correspondence to monophasic first-order kinetics in
soils with half-life values ranging from 4.3 to 4.95 days.
The degradation rate was slight different in both types of
soils. Persistence was higher in sandy loam compared to
silty clay loam soil. Linearity, R2 of calibration curve,
instrument limit of detection/quantitation (LOD/LOQ) was
evaluated. Good linearity (R2 = 0.99) of the calibration
curves for quantification was obtained over the dynamic
range of 0.1–10.0 lg mL-1
, and percent relative standard
deviation was 1.72 %. Leaching experiment showed that
cyazofamid could not leached beyond 15 cm of soil depth.
Maximum concentration was at 5–10 and 10–15 cm soil
depth. Average recoveries from soils fortified at
0.5–5.0 μg g-1 ranged from 78 to 86 %. Instrument LOD
values were 0.01 μg mL-1
, and method LOQ values were
0.05 μg g-1. A fast, easy and efficient method with
acceptable performance was achieved. Results showed that
cyazofamid has a short life in soils and low potential to
leach down under heavy rainfall conditions. Results con-
firm that cyazofamid would not build up in the
environment and have less possibility of groundwater
contamination.
Keywords
Cyazofamid; RP-HPLC; Half-life; Leaching; Dissipation; Kinetics
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