Four-year advanced monitoring program of polar pesticides in groundwater of Catalonia (NE-Spain).
Pesticide contamination of groundwater is of paramount importance because it is the most sensitive and the largest body of freshwater in the European Union. In this paper, an isotopic dilution method based on on-line solid phase extraction-liquid chromatography (electrospray)-tandem mass spectrometry (SPE-LC(ESI)-MS/MS) was used for the analysis of 22 pesticides in groundwater. Results were evaluated from monitoring 112 wells and piezometers coming from 29 different aquifers located in 18 ground water bodies (GWBs), from Catalonia, Spain, for 4 years as part of the surveillance and operational monitoring programs conducted by the Catalan Water Agency. The analytical method developed allows the determination of the target pesticides (6 triazines, 4 phenylureas, 4 organophosphorous, 1 anilide, 2 chloroacetanilides, 1 thiocarbamate, and 4 acid herbicides) in groundwater with good sensitivity (limits of detection <5 ng/L), accuracy (relative recoveries between 85 and 116%, except for molinate), and repeatability (RSD<23%), and in a fully automated way. The most ubiquitous compounds were simazine, atrazine, desethylatrazine and diuron. Direct relation between frequency of detection of each target compound and Groundwater Ubiquity Score index (GUS index) is observed. Desethylatrazine and deisopropylatrazine, metabolites of atrazine and simazine, respectively, presented the highest mean concentrations. Compounds detected in less than 5% of the samples were cyanazine, molinate, fenitrothion and mecoprop. According to the Directive 2006/118/EC, 13 pesticides have individual values above the requested limits (desethylatrazine, atrazine and terbuthylazine lead the list) and 14 samples have total pesticide levels above 500 ng/L. The GWB with the highest levels of total pesticides is located in Lleida (NE-Spain), with 9 samples showing total pesticide levels above 500 ng/L. Several factors such as regulation of the use of pesticides, type of activities in the area, and irrigation were discussed in relation to the observed levels of pesticides.
Water and Soil Quality Research Group, Dept. of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
Marianne
M
Köck-Schulmeyer
Water and Soil Quality Research Group, Dept. of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
Antoni
A
Ginebreda
Water and Soil Quality Research Group, Dept. of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain.
Cristina
C
Postigo
Catalan Water Agency, Provença 204-208, 08036 Barcelona, Spain.
Teresa
T
Garrido
Catalan Water Agency, Provença 204-208, 08036 Barcelona, Spain.
Josep
J
Fraile
Water and Soil Quality Research Group, Dept. of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain. Electronic address: mlaqam@cid.csic.es.
Miren
M
López de Alda
Water and Soil Quality Research Group, Dept. of Environmental Chemistry, IDAEA-CSIC, Jordi Girona 18-26, 08034 Barcelona, Spain; Catalan Institute for Water Research (ICRA), H(2)O Building, Scientific and Technological Park of the University of Girona, Emili Grahit 101, 17003 Girona, Spain.
Damià
D
Barceló
D004784:Environmental Monitoring; D060587:Groundwater / Q000737:chemistry*; D010575:Pesticides / Q000032:analysis* / Q000737:chemistry; D013030:Spain; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014877:Water Pollution, Chemical / Q000706:statistics & numerical data
D010575:Pesticides; D014874:Water Pollutants, Chemical
Catalonia; Groundwater; Monitoring; Polar pesticides