The Occurrence of Triazine Herbicides and Their Transformation Products in the North Fork of the Shenandoah River Using Solid - Phase Extraction and Liquid Chromatography - Mass Spectrometry
Ishan Bardhan, June Liu, and Thomas B. Huff
Male fish in various local rivers have been observed with egg sacks and other troubling female characteristics. These startling occurrences can be attributed in part to the presence of endocrine disrupting chemicals in the river water.
Endocrine disrupting chemicals, which include various pharmaceuticals and herbicides, act like hormones in the endocrine system, thus disrupting the actions and functions of native hormones. One such endocrine disrupting chemical is atrazine, the most commonly administered herbicide in the United States . Despite being banned in the European Union for its suspected collateral effects, atrazine is nevertheless utilized to a great extent in the US , with harmful consequences already having been detected in various river dwelling amphibians. This is the result of improperly controlled runoff following the chemical's administration in agricultural areas.
Our goal was to collect and analyze river samples in order to detect and determine the concentrations of atrazine and its transformation products in Virginia rivers. Samples were collected from the North Fork of the Shenandoah River and carefully filtered in order to remove suspended particulates. Samples were then spiked with a surrogate solution and extracted using solid phase extraction (SPE) techniques. Our extracted samples were then concentrated by evaporation and transferred into 2 mL vials. They were then analyzed using liquid chromatography-mass spectrometry (LCMS) to determine the presence and concentration of atrazine and its transformation products.
The LCMS data provided predictable, yet alarming results. Noticeable concentrations of atrazine were detected in each individual sample, as hypothesized. The percentage of parent compounds decreased with each subsequent sample as the chemical degenerated since application in spring. However, the breakdown products of atrazine (of which there are seven) actually increased in concentration since the atrazine was applied months ago. This discovery is troubling and leaves much possibility for future research.
Figure 1: Triazine Herbicide Transformation Products, SIM: Simazine, ATR: Atrazine, PROP: Propazine, DEDIA: Desethyl Desisopropyl Atrazine (Diaminoatrazine), HA: 2-Hydroxy Atrazine, DIA: Desisopropyl Atrazine, DEA: Desethyl Atrazine, DIHA: Desisopropyl-2-Hydrozy Atrazine, DEHA: Desethyl Atrazine
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