The application of LC-MS technologies for the detection of triazine herbicides in water

Michael Cahill, Department of Chemistry, Cork Institute of Technology, Cork, Ireland.


The triazine herbicides, including, simazine (6-chloro-N,N’-diethyl-1,3,5-triazine-2,4- diamine), atrazine (2-chloro-4-ethylamino-6-isopropylamino-l,3,5-triazine) and cyanazine were developed as selective weed killers. Their design function is to disrupt the photosynthesis of broad-leafed plants. In the intensive production of grasses (e.g. wheat, cereals, etc.) broad-leafed plants growing in the grass production area are economically costly, competitors with the grasses for nutrients; their removal is facilitated by triazines herbicides and simazine and atrazine are the predominant compounds used. Significant amounts of triazine herbicides are consumed by the agricultural industry each year. However, due to the indiscriminate use of pesticides/herbicides, traces of herbicides have been found in run-off waters and leachate from agriculture lands. These herbicides can pose a risk to the health of humans and animals as they are suspected carcinogens. The European Community has put in place regulations in order to protect human health, wildlife and the environment. The Regulations designated, SI 439 of 2000, set the following standards for pesticides/herbicides and related products: (A) 0.1 µg/1 for each other individual pesticide/herbicide and related product (such as a growth regulator) and their relevant metabolites, degradation and reaction products; and (B) 0.5 µg/1 for total pesticides/herbicides. In surface water, these limits are about an order of magnitude higher (1-3 µg/1). The current maximum contaminant level (MCL) for drinking water for atrazine is 3 µg/1 and the contaminant level goal (MCLG) for simazine has been set at 4 µg/1 (ppb). It is therefore imperative that adequate monitoring programmes are implemented in Ireland to assess the triazines herbicides levels in reservoir water, drinking water and wastewater treatment processes. Under the present research a sensitive and specific LC-MS/MS analytical method was developed and validated to quantitatively determine herbicides in various sample matrices and hence establish if County Cork, the largest agricultural county in Ireland, has an environmental problem associated with triazine herbicides.