Pesticide Contamination of Ground Water Artificially Recharged by Farmland Runoff

Atrazine, cyanazine, alachlor, and metolachlor in the surface water of a recharge structure, which impounds runoff from row-cropped farmland in Nebraska, are transported with seepage to the shallow ground water flow system and to the locally confined regional aquifer. All wells in the shallow flow system and all those in the regional flow system impacted by seepage from the structure had detectable concentrations of at least one of the four pesticides.
The detectable concentrations of cyanzine, alachlor, and metolachlor in the two flow systems ranged from 0.1 to 0.9 ppb. These concentrations were an order of magnitude lower than those in the surface water. Concentrations in the regional aquifer clustered at the lower end of this concentration range. These three pesticides were not detected in the baseline study of the regional aquifer.
Unlike alachlor, cyanzine, and metolachlor, atrazine was always present in the wells impacted by seepage from the recharge structure. In the shallow flow system, concentrations ranged from 0.3 to 8.8 ppb and from 0.1 to 2.5 ppb in the regional aquifer. The average of the detectable atrazine concentrations in the baseline study was 0.04 ± 0.05 ppb.     

Large-scale pesticide monitoring across Great Barrier Reef catchments--Paddock to Reef Integrated Monitoring, Modelling and Reporting Program

The transport and potential toxicity of pesticides in Queensland (QLD) catchments from agricultural areas is a key concern for the Great Barrier Reef (GBR). In 2009, a pesticide monitoring program was established as part of the Australian and QLD Governments' Reef Plan (2009). Samples were collected at eight End of System sites (above the tidal zone) and three sub-catchment sites. At least two pesticides were detected at every site including insecticides, fungicides, herbicides, and the Reef Plan's (2009) five priority photosystem II (PSII) herbicides (diuron, atrazine, hexazinone, tebuthiuron and ametryn). Diuron, atrazine and metolachlor exceeded Australian and New Zealand water quality guideline trigger values (TVs) at eight sites. Accounting for PSII herbicide mixtures increased the estimated toxicity and led to larger exceedances of the TVs at more sites. This study demonstrates the widespread contamination of pesticides, particularly PSII herbicides, across the GBR catchment area which discharges to the GBR.     

Surveying Upstate NY Well Water for Pesticide Contamination: Cayuga and Orange Counties

Private wells in Cayuga and Orange counties in New York were sampled to determine the occurrence of pesticide contamination of groundwater in areas where significant pesticide use coincides with shallow or otherwise vulnerable groundwater. Well selection was based on local groundwater knowledge, risk modeling, aerial photo assessments, and pesticide application database mapping. Single timepoint samples from 40 wells in each county were subjected to 93‐compound chromatographic scans. All samples were nondetects (reporting limits ≤1 μg/L), thus no wells from either county exceeded any of 15 state groundwater standards or guidance values. More sensitive enzyme‐linked immunosorbent assays (ELISA) found two wells with quantifiable atrazine in each county (0.1–0.3 μg/L), one well with quantifiable diazinon (0.1 μg/L) in Orange County, and one well with quantifiable alachlor (0.2 μg/L) in Cayuga County. Trace detections (<0.1 μg/L) in Cayuga County included atrazine (five wells), metolachlor (six wells), and alachlor (one well), including three wells with multiple detections. All 12 Cayuga County wells with ELISA detections had either corn/grain or corn/forage rotations as primary surrounding land uses (although 20 other wells with the same land uses had no detections) and all quantified detections and most trace detections occurred in wells up to 9‐m deep. Orange County trace (<0.1 μg/L) ELISA detections (atrazine three wells, diazinon one well, and metolachlor five wells) and quantified detections were only generally associated with agricultural land uses. Finding acceptable drinking water quality in areas of vulnerable groundwater suggests that water quality in less vulnerable areas will also be good.     

Pesticides in Nebraska's Ground Water

More than 2263 well water samples were collected throughout Nebraska and analyzed for pesticides. Thirteen and one-half percent contained detectable levels of atrazine, but only 22 wells exceeded the health advisory of 3.0 ppb. Although the samples came from almost every county in the state, this sampling is not based solely on a randomly selected group of wells. The highest frequency of detections occurred in irrigated corn-growing areas with less than 50 feet to ground water. These areas were sampled at a greater frequency than the less vulnerable areas. Cyanazine, together with the additional triazines — simazine, propazine, prometone, and ametryne, also were detected in some well waters; however, their frequency of detection was well below that of atrazine. The triazine metribuzin was not detected.
Alachlor, propachlor, and metolachlor also were detected in trace levels in several wells. Five of 2072 samples analyzed for alachlor exceeded the health advisory of 0.4 ppb. Almost all of the contaminated wells were in vulnerable areas. The relatively high frequency of propachlor detections occurred in predominately irrigated corn-growing areas, rather than in areas where propachlor is traditionally applied.
The factors that appear most directly involved in the observed distribution of pesticides in ground water are the intensity of areal usage, pesticide persistence and mobility, irrigation, soil drainage capacity, and depth to ground water.
Fifteen pesticide residues were detected during this study. If ethylene dibromide and carbon tetrachloride, which were detected in ground water adjacent to grain elevators are included, a total of 17 pesticide residues have been detected in Nebraska's ground water.     

Agricultural pollutant penetration and steady state in thick aquifers

The leakage of pollutants from agricultural lands to aquifers has increased greatly, driven by increasing fertilizer and pesticide use. Because this increase is recent, ground water pollutant concentrations, loads, and exports may also be increasing as pollutants penetrate more deeply into aquifers. We established in an aquifer profile a ground water recharge and pollutant leakage chronology in an agricultural landscape where 30 m of till blankets a 57-m thick sandstone aquifer. Pollutant concentrations increased from older ground water (1963) at the aquifer base to younger ground water (1985) at its top, a signal of increasing pollutant leakage. Nitrate-N increased from 0.9 to 13.2 mg/L, implying that leakage increased from 1.9 to 16.5 kg/ha/year. Nitrate load and export could increase from 130% to 230% before reaching a steady state in 20 to 40 years. Chloride increases were similar. Pesticide residues alachlor ethane sulfonic acid (ESA), metolachlor ESA, and atrazine residues partially penetrated the aquifer profile. Their concentration-age-date patterns exhibited an initial increase and then a leveling corresponding to the timing of product adoption and leveling of demand. Unlike NO(3), projecting pesticide residue steady states is complicated by the phasing in and out of pesticide products over time; for example, neither alachlor nor atrazine is currently used in the area, and newer products, which have not had time to transit to the aquifer, have been adopted. The circumstances that resulted in the lack of a pollutant steady state are not rare; thus, the lack of steady states in agricultural region aquifers may not be uncommon.     

Nitrate and herbicide loading in two groundwater basins of Illinois'' sinkhole plain

This investigation was designed to estimate the mass loading of nitrate (NO₃⁻) and herbicides in spring water discharging from groundwater basins in an agriculturally dominated, mantled karst terrain. The loading was normalized to land use and NO₃⁻ and herbicide losses were compared to estimated losses in other agricultural areas of the Midwestern USA. Our study area consisted of two large karst springs that drain two adjoining groundwater basins (total area of 37.7 km²) in southwestern Illinois' sinkhole plain, USA. The springs and stream that they form were monitored for almost 2 years. Nitrate–nitrogen (NO₃–N) concentrations at three monitoring sites were almost always above the background concentration (1.9 mg/l). NO₃–N concentrations at the two springs ranged from 1.08 to 6.08 with a median concentration of 3.61 mg/l. Atrazine and alachlor concentrations ranged from <0.01 to 34 μg/l and <0.01 to 0.98 μg/l, respectively, with median concentrations of 0.48 and 0.12 μg/l, respectively. Approximately 100,000 kg/yr of NO₃–N, 39 kg/yr of atrazine, and 2.8 kg/yr of alachlor were discharged from the two springs. Slightly more than half of the discharged NO₃⁻ came from background sources and most of the remainder probably came from fertilizer. This represents a 21–31% loss of fertilizer N from the groundwater basins. The pesticide losses were 3.8–5.8% of the applied atrazine, and 0.05–0.08% of the applied alachlor. The loss of atrazine adsorbed to the suspended solid fraction was about 2 kg/yr, only about 5% of the total mass of atrazine discharged from the springs.     

Effect of Various Materials in Multilevel Samplers on Monitoring Commonly Occurring Agrichemicals in Ground Water

Studies have shown that materials, such us polytetra-fluoroethylene (PTFE), rigid polyvinyl chloride (rigid PVC). flexible polyvinyl chloride (flexible PVC), stainless steel (SS). low-density polyethylene (LDPE), and high-density polyethylene (HDPE), have the potential to influence certain analyte concentrations in ground water samples. The effects of HDPE, LDPE, PTFE, rigid PVC, and SS on aqueous concentrations of nitrate-N, atrazine, deethylatrazine (DEA), and deisopropylatrazine (DIA) were evaluated in a field study A laboratory study was conducted to evaluate sorption of atrazine DEA, DIA, cyanazine, alachlor, metolachlor, and butachlor to PTFE, HDPE, and SS materials. Butachlor is rarely use in the United States, but was included because of its expected high sorptivity. No significant differences between HDPE, LDPE, PTFE, rigid PVC, and SS were determined for any of the analytes tested in the field study. In the laboratory study, sorption of DIA to PTFE and SS was significant at 2.6 × 10⁻⁵ and 4.1 × 10⁻⁵μg/m² respectively. Sorption of DIAA to HDPE was not significantly > 0 sorption of all other compounds to HDPE, PTFE, and SS were also not significantly >0. Results of the two studies indicate that for these analytes (relatively polar or ionized compounds), representative ground water samples are not dependent on the materials used for multilevel sampler construction. When considering these compounds, it appears that the least expensive materials (HDPE, rigid PVC, and LDPE) are good choices for the construction of ground water monitoring wells.     

The influence of a season of extreme wet weather events on exposure of the World Heritage Area Great Barrier Reef to pesticides

The 2010-2011 wet season was one of extreme weather for the State of Queensland, Australia. Major rivers adjacent to the Great Barrier Reef (GBR) were discharging at rates 1.5 to >3 times higher than their long term median. Exposure to photosystem II herbicides has been routinely monitored over a period of up to 5 years at 12 inshore GBR sites. The influence of this wet season on exposure to photosystem II herbicides was examined in the context of this long-term monitoring record and during flood plume events in specific regions. Median exposures expressed as diuron equivalent concentration were an average factor of 2.3 times higher but mostly not significantly different (p<0.05) to the median for the long-term monitoring record. The herbicides metolachlor and tebuthiuron were frequently detected in flood plume waters at concentrations that reached or exceeded relevant water quality guidelines (by up to 4.5 times).     

Effects of Photosystem II inhibiting herbicides on mangroves--preliminary toxicology trials

Mangroves are sensitive to the root application of Photosystem II inhibiting herbicides and Avicennia marina is more sensitive than other mangroves tested. Seedlings of four mangrove species, including two salt-excreting species (A. marina and Aegiceras corniculatum) and two salt-excluding species (Rhizophora stylosa and Ceriops australis) were treated with a range of concentrations of the herbicides diuron, ametryn and atrazine. Assessment of responses required the separation of seedlings into two groups: those that had only their roots exposed to the herbicides through the water (A. marina and R. stylosa) and those that had both roots and leaves exposed to herbicides through the water (A. corniculatum and C. australis). Salt-excreting species in each group were more susceptible to all herbicide treatments than salt-excluding species, indicating that root physiology was a major factor in the uptake of toxic pollutants in mangroves. Submergence of leaves appeared to facilitate herbicide uptake, having serious implications for seedling recruitment in the field. Each herbicide was ranked by its toxicity to mangrove seedlings from most damaging to least effective, with diuron>ametryn>atrazine. The relative sensitivity of A. marina found in these pot trials was consistent with the observed sensitivity of this species in the field, notably where severe dieback had specifically affected A. marina in the Mackay region, north eastern Australia.     

Portable rainfall simulator for plot-scale investigation of rainfall-runoff,and transport of sediment and pollutants

A low-cost, simple to use portable rainfall simulator is developed for use over a 5 m^2 plot. The simulator is easy to transport and assemble in the field, thereby allowing for necessary experimental replicates to be done. It provides rainfall intensities of between 20 and 100 mm/h by changing the number and type of silicon nozzles used. The Christiansen coefficient of uniformities obtained in the field are appropriate and vary from 79 to 94% for rainfall intensities ranging from 30 to 70 mm/h. In addition, the median volumetric drop diameters measured for rainfall intensities of 30, 50, and 70 mm/h are in the lower range of that of natural rainfall and equal to 1.10 ± 0.08,1.69 ± 0.21, and 1.66 ± 0.20 mm, respectively. The velocities of the raindrops with diameters less than 1.2 mm reached terminal velocities, while raindrops less than 2.0 mm achieved velocities reasonably close to the terminal velocity of natural rainfall. Furthermore,the average time-specific kinetic energy(KET) for rainfall intensities of 30, 50, and 70 mm/h are 257.7,760.1, and 1645.2 J/m^2/h, respectively accounting for about 78.0 and 86.5% of the KET of natural rainfall for50 and 70 mm/h rainfall intensity, respectively. The applicability of the portable rainfall simulator for herbicide transport study is investigated using two herbicides(atrazine and metolachlor); herbicide losses in runoff and sediment samples are in the ranges reported in the literature. As a percentage of the amount of herbicide applied, 5.29% of atrazine and 2.15% of metolachlor are lost due to combined water and sediment runoff. The results show that the portable rainfall simulator can be effectively used in studying processes such as pesticide runoff, infiltration mechanisms, and sediment generation and transport at a field plot scale with an emphasis on how surface characteristics such as slope and soil properties affect these processes.     

Herbicide contamination and the potential impact to seagrass meadows in Hervey Bay, Queensland, Australia

Low concentrations of herbicides (up to 70 ng l(-1)), chiefly diuron (up to 50 ng l(-1)) were detected in surface waters associated with inter-tidal seagrass meadows of Zostera muelleri in Hervey Bay, south-east Queensland, Australia. Diuron and atrazine (up to 1.1 ng g(-1) dry weight of sediment) were detected in the sediments of these seagrass meadows. Concentration of the herbicides diuron, simazine and atrazine increased in surface waters associated with seagrass meadows during moderate river flow events indicating herbicides were washed from the catchment to the marine environment. Maximum herbicide concentration (sum of eight herbicides) in the Mary River during a moderate river flow event was 4260 ng l(-1). No photosynthetic stress was detected in seagrass in this study during low river flow. However, with moderate river flow events, nearshore seagrasses are at risk of being exposed to concentrations of herbicides that are known to inhibit photosynthesis.     

Comparative effects of herbicides on photosynthesis and growth of tropical estuarine microalgae

Pulse amplitude modulation (PAM) fluorometry is ideally suited to measure the sub-lethal impacts of photosystem II (PSII)-inhibiting herbicides on microalgae, but key relationships between effective quantum yield [Y(II)] and the traditional endpoints growth rate (mu) and biomass increase are unknown. The effects of three PSII-inhibiting herbicides; diuron, hexazinone and atrazine, were examined on two tropical benthic microalgae; Navicula sp. (Heterokontophyta) and Nephroselmis pyriformis (Chlorophyta). The relationships between Y(II), mu and biomass increase were consistent (r(2)0.90) and linear (1:1), validating the utility of PAM fluorometry as a rapid and reliable technique to measure sub-lethal toxicity thresholds of PSII-inhibiting herbicides in these microalgae. The order of toxicity (EC(50) range) was: diuron (16-33nM)>hexazinone (25-110nM)>atrazine (130-620nm) for both algal species. Growth rate and photosynthesis were affected at diuron concentrations that have been detected in coastal areas of the Great Barrier Reef.     

Degradates provide insight to spatial and temporal trends of herbicides in ground water

Since 1995, a network of municipal wells in Iowa, representing all major aquifer types (alluvial, bedrock/karst region, glacial drift, bedrock/nonkarst region), has been repeatedly sampled for a broad suite of herbicide compounds yielding one of the most comprehensive statewide databases of such compounds currently available in the United States. This dataset is ideal for documenting the insight that herbicide degradates provide to the spatial and temporal distribution of herbicides in ground water. During 2001, 86 municipal wells in Iowa were sampled and analyzed for 21 herbicide parent compounds and 24 herbicide degradates. The frequency of detection increased from 17% when only herbicide parent compounds were considered to 53% when both herbicide parents and degradates were considered. Thus, the transport of herbicide compounds to ground water is substantially underestimated when herbicide degradates are not considered. A significant difference in the results among the major aquifer types was apparent only when both herbicide parent compounds and their degradates were considered. In addition, including herbicide degradates greatly improved the statistical relation to the age of the water being sampled. When herbicide parent compounds are considered, only 40% of the wells lacking a herbicide detection could be explained by the age of the water predating herbicide use. However, when herbicide degradates were also considered, 80% of the ground water samples lacking a detection could be explained by the age of the water predating herbicide use. Finally, a temporal pattern in alachlor concentrations in ground water could only be identified when alachlor degradates were considered.     

Heterogeneous Nucleophilic Transformation of Metolachlor by Bisulfide on Alumina Surface

The present research elucidates the accelerating effect of alumina minerals on metolachlor transformation using sulfur nucleophiles and also determines the metolachlor transformation mechanisms in the heterogeneous reaction systems. Metolachlor transformation was first systematically investigated under different conditions. Then, the Fourier transform infrared (FTIR) spectra were used to characterize the changes in the surface bonds of the aluminas. The transformation products were qualitatively identified using LC/MS. The results showed that bisulfide can produce efficient metolachlor transformation rates, and the presence of the aluminas can further accelerate the transformation by achieving complete transformation in <21 days. In addition, a higher pH and higher bisulfide concentration are more favorable for metolachlor transformation. When normalized to the surface area, the metolachlor transformation rates were found to follow the order of α‐Al₂O₃>γ‐AlOOH>γ‐Al₂O₃ in the presence of different aluminas. FTIR results indicated that the enhancement of metolachlor transformation rates by bisulfide with aluminas can be attributed to the surface active nucleophiles on alumina surfaces formed through Al? S and Al? O bonds. The substitution of chlorine on the metolachlor followed the S_N2 mechanism by bisulfide with accelerated rate through mediating the heterogeneous reactions with aluminas.     

Pestizide in Österreichs Fließgewässern – ein bundesweiter Überblick

Pesticides in Austrian Running Waters – a Country-wide Overview The analyses of pesticides in Austrian running waters are major part of the country-wide water quality monitoring system which has been established in 1991. This paper summarizes the data which were collected for 29 substances between December 1991 and June 1995. The monitoring activities focus on herbicides because they are the most important pesticide group in Austria. Substances of the triazines and phenoxyalkanecarboxylic acid group analyzed within the programme represent the major part of the total amount of herbicides applied. The most detected pesticides were atrazine and its metabolite deethylatrazine. Peak concentrations were obtained in rivers situated in the eastern and southern regions of Austria with intensive agriculture. Other substances play a minor role as contaminants in running waters. These findings correspond to the data obtained by investigations of groundwater in porous media.     

Modelling metolachlor exports in subsurface drainage water from two structured soils under maize (eastern France)

The study investigated the processes involved in metolachlor transport in two artificially drained, structured soils in eastern France. Measured losses of bromide and metolachlor in drainage water were compared with results simulated by the mechanistic, stochastic AgriFlux model. Simulated drainage water volumes were generally similar to the measured volumes when the spatial variability of the soil water properties was taken into account. When such variability was disregarded, cumulative water volumes of the clay soil were over- or underestimated by more than 20%. Two types of adsorption were tested. For instantaneous, reversible adsorption, using the partition coefficient Koc, metolachlor losses were underestimated in the first drainage water volumes and overestimated for the total study period. The use of slow adsorption and desorption kinetics (ADK) produced an export pattern similar to the observed one. A sensitivity analysis indicated that the simulated results are very sensitive to the values of the ADK rates, especially for the silty loam soil. The effect of ADK on the attenuation of metolachlor exports was more significant than the effect of degradation (2.3 and 6.7 times higher for the clay and silty loam soils, respectively). For the same four-month period, the bromide and metolachlor losses (using ADK) in the clay soil were 2.1 and 1.3 times greater, respectively, if the macroporosity was set at 10% than if it was not simulated. Conversely, macroporosity did not significantly affect these losses in the silty loam. The main factors involved in the metolachlor transport in the studied soils were: (i) the macroporosity, especially in the clay soil because of the low hydraulic conductivity of the matrix and (ii) the sorption kinetics rates which varied according to the soil physico-chemical characteristics.     

Sediments, nutrients and pesticide residues in event flow conditions in streams of the Mackay Whitsunday Region, Australia

The Mackay Whitsunday region covers 9000 km(2) in northeastern Australia. A study of diffuse pollutants during high flow events was conducted in coastal streams in this region. Sampling was conducted in the Pioneer River catchment during a high flow event in February 2002 and in Gooseponds Creek, Sandy Creek and Carmila Creek in March 2003. Concentrations of five herbicides; atrazine (1.3 microg l(-1)), diuron (8.5 microg l(-1)), 2,4-D (0.4 microg l(-1)), hexazinone (0.3 microg l(-1)) and ametryn (0.3 microg l(-1)) and high concentrations of nutrients (total nitrogen 1.14 mg l(-1), total phosphorus 0.20 mg l(-1)) and suspended sediments (620 mg l(-1)) were measured at Dumbleton Weir on the lower reaches of the Pioneer River. Drinking water guidelines for atrazine and 2,4-D were exceeded at Dumbleton Weir, low reliability trigger values for ecosystem protection for diuron were exceeded at three sites and primary industry guidelines for irrigation levels of diuron were also exceeded at Dumbleton Weir. Similar concentrations were found in the three smaller streams measured in 2003. Herbicides and fertilisers used in sugarcane cultivation were identified as the most likely major source of the herbicide residues and nutrients found.     

The mobility, partitioning and degradation of atrazine and simazine in the salt marsh environment

The transfer of the s-triazine herbicides onto a salt marsh and their subsequent behaviour and fate has been investigated in a series of laboratory-based experiments. The results indicate that atrazine and simazine enter the marsh system and undergo negligible adsorption onto suspended solids. Herbicide accumulation within the sediment compartment was thought to be due to other mechanisms such as partitioning into the surface microlayer, or association with sediment flocs. s-Triazine mobility within the sediment was dictated by compound and sediment type, reflecting greater mobility in the mud flat than the vegetated marsh sediment. The majority of the herbicides were, however, retained in the uppermost layers of the sediment profile indicating that salt marsh sediments act as a sink for these compounds. Although degradation rates in the sediment were relatively rapid, detectable levels of the parent compounds were still evident after 71 days, which implies that these compounds may persist in salt marsh sediments. The absence of degradation in the aqueous phase implies that adsorption to particulate matter is a prerequisite for the degradation of the s-triazine herbicides.     

Identification and quantification of pesticides, industrial chemicals, and organobromine compounds of medium to high polarity in the North Sea

Solid-phase extraction of 20 L seawater samples enabled the enrichment and determination of a wide array of organic substances, including compounds of medium to high polarity, in the pg/L-range. A number of contaminants was detected and quantified throughout the North Sea, among them the pesticides dichlobenil (2,6-dichlorobenzonitrile), metolachlor and terbuthylazine as well as the industrial chemicals dichloropyridines (DCPy, 4 isomers) and nitrobenzene. Concentrations attained values up to 1.4 ng/L for dichlobenil, 0.83 ng/L for terbuthylazine, 0.61 ng/L for metolachlor, 0.13 ng/L for 2,6-DCPy, 4.37 ng/L for nitrobenzene and 1-8 ng/L for tris(chloropropyl)phosphates (TCPP). A number of North Sea water samples was screened for non-target compounds, revealing the presence of further contaminants, e.g., lindane and TCPP, as well as several biogenic and/or anthropogenic organobromine substances, among which bromoindols, -phenols and -anisoles were identified.     

Bestimmung von Atrazin,Terbutylazin und ihrer Desethyl- sowie Hydroxymetaboliten in Boden mittels SFE und HPLC/UV-DAD

Determination of Atrazine, Terbutylazine and their Deethyl- and Hydroxymetabolites in Soil by SFE and HPLC/UV-DAD The supercritical fluid extraction (SFE) (CO₂ and CH₃OH as modifier) of the herbicides atrazine and terbutylazine as well as their deethyl- and hydroxymetabolites from soil was investigated. The analytes were determined after extraction by HPLC/UV-DAD using a C18 column. The limits of detection of the chromatographic step were between 0.01 μg/mL and 0.07 μg/mL, the relative standard deviations between 0.8% and 1.4%. With the aid of a control chart, the stability of the chromatographic system was evaluated. For extraction, soil was spiked with 5 μg/g for each component. For SFE, CO₂ and methanol as modifier were used, and a pressure program was applied. Beside SFE, Soxhlet extraction with methanol and a solid-liquid extraction with acetone/water by shaking were carried out. For chlorine-containing triazines, the recovery rates were comparable for all extraction methods. The following recovery rates for SFE were obtained: deethylterbutylazine 77.4%, terbutylazine 80.2%, deethylatrazine 87.4%, atrazine 92.6%. However, the recovery rates for the hydroxymetabolites (4.1% for hydroxyatrazine, 21% for hydroxyterbutylazine) were not satisfying compared with the “classical” methods of extraction (above 50%). The limits of detection for the total process (SFE and HPLC/UV-DAD) estimated by the signal to noise ratio amounted 0.08 μg/g soil for chlorine-containing derivates, for hydroxyatrazine 2…3 μg/g, and for hydroxyterbutylazine 0.8 μ/g.