S-Trazine Herbicides And Their Transformation Products in the North Fork of the Shenandoah River
Thomas B. Huff, Jun Liu and Gregory D. Foster
Surface water samples were taken during seven consecutive months from April through October 2008 from two different regions in the Shenandoah River watershed within the Potomac River basin. Five sites were monitored on the Shenandoah River including four sites on the North Fork near the town of Timberville, Virginia and one reference site on the South Fork near Luray, Virginia.
The samples were filtered and extracted using solid phase extraction. Extracts were analyzed by liquid chromatography-mass spectrometry for atrazine, simazine and propazine and their primary transformation products hydroxy atrazine, desethyl atrazine and desisopropyl atrazine. It has been surmised that these transformation products have the same ecological impacts as their parent compounds.
The samples demonstrated seasonal high concentrations during the springtime application period. They also showed that the transformation products persisted throughout the study period even while the parent compound concentrations decreased. The data showed that the transformation products had a greater overall contribution to the total s-triazine herbicide burden on the streams except during application periods during major storms..
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