Optimization of ultrasonic extraction and analyses methodology by HPLC for determination of diuron and its metabolites in soil cultivation of sugar cane.

Patrícia Cavani Martins de Mello, Ilza Lobo, Maria Josefa Santos Yabe

Abstract


Diuron, N-(3,4-dichlorophenyl)-N, N-dimethylurea can be transformed into the soil through the biodegradation of 3-(3,4-dichlorophenyl)-3-methylurea (DCPMU), 3.4-diclorofenilureia (DCPU) and 3,4-dichloroaniline (DCA). This study aimed to optimize and validate a method of extraction and analysis of these substances in the soil by HPLC/DAD. There was extracted with methanol in the bath ultrasonic and analysis in a liquid chromatograph/detector brand Waters. The condition of analysis optimized for separation of analytes was mobile phase methanol: water 50:50 (v / v), flow 1 mL min-1. Wavelength of 240 nm was selected for the DCA and 254 nm for diuron, DCPMU and DCPU. It was used column and pre column Waters Xterra RP18, 5 um, 4.6 and 3.9 x 150 mm x 20 mm. The calibration curve was obtained from the fortification of the soil with the mixture of patterns in the range of 5 mg Kg-1 to 200 mg Kg-1 of soil. The recovery was obtained in two concentration levels of 5 and 200 mg. Kg-1 of soil was between 85 and 99%. The repeatability was 0.78%, 2.20%, 2.17% and 1.72% and intermediate precision was 2.48%, 2.11%, 3.10% and 2.77% for diuron, DCPMU, DCPU and DCA, respectively. The limit of quantification was 1.25 mg Kg-1 soil. The concentration of diuron found in some bioaugmented soil samples ranged from 5.5 to 8.9 mg Kg-1 soil, but was not detected the presence of their metabolites.


Keywords


Diuron; Metabolites; Sugarcane; Validation; High Performance Liquid Chromatography;Bioaugmentation.



DOI: http://dx.doi.org/10.5433/1679-0375.2009v30n2p107

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