A. Saez

UV detection of triazine herbicides and their hydroxylated and dealkylated degradation products in well water

The aim of this work was to develop a simple method to confirm the presence of hydroxytriazine products (hydroxyatrazine, hydroxysimazine, hydroxyethylterbutyltriazine and hydroxydiaminotriazine) in water and to apply it to well water samples. The hydroxytriazines were concentrated on a Sep-Pak C18 cartridge. Analysis was performed by HPLC using an RP8-DB column with phosphate buffer (pH 4.7)-acetonitrile (72:28, v/v) as the mobile phase and photodiode-array detection at 233 nm. Hydroxyatrazine, hydroxysimazine and hydroxyethylterbutyltriazine were detected at ppb levels in samples from two shallow wells under a very sandy soil citrus orchard taken at three different times in a 1-year period.

Residual herbicide movement in soil columns

Abstract Atrazine, bromacil, diuron, simazine, terbuthylazine, terbumetone, terbutyrne and trifluran are selective residual herbicides on citrus and very common in Spanish orchards. As a first step to measure the herbicide penetration in soil and therefore the risk of contamination, soil columns (40 cm in length, 9 cm interior diameter) were packed with an altered, screened loam soil. Simulated treatments were made by pouring, with a pipette, a solution of the chemicals on the soil surface. After the application, irrigations were done until the appearance of drainage water. Herbicide analyses were performed, at five soil depths, using high performance liquid chromatography for diuron (limit of detection 0.04 ppm) and gas chromatography for the rest of the chemicals (0.01 ppm). The leaching potential, in decreasing order was: bromacil > atrazine > simazine > terbumetone > terbuthylazine > terbutryene = diuron > trifluralin.