Santos, TCRRocha, Julio Cesar [UNESP]Alonso, R. M.Martinez, E.Ibanez, C.Barcelo, D.2014-05-202014-05-201998-11-15Environmental Science & Technology. Washington: Amer Chemical Soc, v. 32, n. 22, p. 3479-3484, 1998.0013-936Xhttp://hdl.handle.net/11449/33715Propanil and its major degradation product, 3,4-dichloroaniline (DCA), were monitored in surface water and soil samples from two rice fields of the Ebre Delta area (Tarragona, Spain) following agricultural application. On-line solid-phase extraction (SPE) (water) and Soxhlet extraction (soil) followed by liquid chromatography/diode array detection (LC/DAD) were used for the trace determination of both compounds. Unequivocal confirmation/identification was conducted by using liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry, LC/APCI/MS (using negative and positive ionization modes). Concentrations of the herbicide propanil in water samples varied from 1.9 to 55.9 mu g/L. Propanil degraded very rapidly to DCA, and high concentrations of this product were found, varying from 16.5 to 470 mu g/L in water and 119 +/- 22 mu g/kg in soil samples. No detectable DCA (<0.001%) was found in the applied pesticide formulation, indicating that DCA formation took place after propanil application. These field results compared favorably with laboratory experiments showing that humic interactions had a strong influence on the pesticide degradation. The half-lifes under real conditions for propanil and DCA, calculated using a first-order decay, were 1.2 and 1.6 days, respectively.3479-3484engArtigo10.1021/es980212kWOS:000076986800005Acesso restrito4148837403618207