[LC-MS/MS analysis of herbicide residues in waters from Navarre].

BACKGROUND The aim of the study was to obtain information on the residues of herbicides (imazametabenz, simazine, isoproturon, clortoluron, metribuzine, atrazine, cianazine, terbutrin, propanil, terbutilazine, alachlor and pendimetalin) present in water proceeding from Navarre. MATERIAL AND METHODS A total of 465 samples of water were taken: 378 were taken from 141 water supplies; the remaining 87 proceeded from fountains, springs and borings in agricultural areas in the south of Navarre. The technique employed was LC-MS/MS. RESULTS Herbicide residues were detected in 33% of the water supplies, and their concentration exceeded the normative limit in 8% of them. Herbicide residues were found in 86% of the samples from wells and fountains of the agricultural areas of the south of Navarre. The number of water supplies with herbicide residues increased from north to south. However, the percentage of water supplies in which the concentration of herbicides exceeded the limits was greater in the centre of Navarre than in the north and south. Imazametabenz was the herbicide most detected in the samples from the northern, central and southern areas. Atrazine, terbutilazine and imazametabenz were most detected in the samples of the southern area. CONCLUSIONS The differences amongst the three areas of Navarre can be explained as being due to the different agricultural practices of each area. Concentrations of herbicides exceeding the normative limits were not detected in any of the water samples proceeding from the larger towns of Navarre.