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Journal of Environmental Science and Health, Part B: Pesticides, Food Contaminants, and Agricultural Wastes Publication details, including instructions for authors and subscription information: http://www.tandfonline.com/loi/lesb20
Adaptation and validation of QuEChERS method for the analysis of trifluralin in wind-eroded soil a
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Cemile Temur , Osman Tiryaki , Oguzhan Uzun & Mustafa Basaran
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Department of Plant Protection, Faculty of Seyrani Agriculture , Erciyes University , Kayseri , Turkey b
Department of Soil Science, Faculty of Seyrani Agriculture , Erciyes University , Kayseri , Turkey Published online: 02 Jul 2012.
To cite this article: Cemile Temur , Osman Tiryaki , Oguzhan Uzun & Mustafa Basaran (2012) Adaptation and validation of QuEChERS method for the analysis of trifluralin in wind-eroded soil, Journal of Environmental Science and Health, Part B: Pesticides, Food Contaminants, and Agricultural Wastes, 47:9, 842-850, DOI: 10.1080/03601234.2012.693878 To link to this article: http://dx.doi.org/10.1080/03601234.2012.693878
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Journal of Environmental Science and Health, Part B (2012) 47, 842–850 C Taylor & Francis Group, LLC Copyright ISSN: 0360-1234 (Print); 1532-4109 (Online) DOI: 10.1080/03601234.2012.693878
Adaptation and validation of QuEChERS method for the analysis of trifluralin in wind-eroded soil CEMILE TEMUR1, OSMAN TIRYAKI1, OGUZHAN UZUN2 and MUSTAFA BASARAN2 1
Department of Plant Protection, Faculty of Seyrani Agriculture, Erciyes University, Kayseri, Turkey Department of Soil Science, Faculty of Seyrani Agriculture, Erciyes University, Kayseri, Turkey
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This study was carried out to develop and validate a reliable analytical procedure for trifluralin analysis in wind-eroded sediments. Soil sediments trapped in BEST sediment traps were subjected to QuEChERS extraction method, incorporating a simple simultaneous cleanup step, followed by trifluralin analysis with GC-ECD. Results revealed that QuEChERS method offered a potential alternative technique for pesticide extraction from soil samples. The validity of analytical method was performed by the method-performance criteria such as, recovery, LOD, LOQ repeatability, precision, and all found to be within the required limits. It was also observed in this study that herbicide concentrations in the wind-eroded sediment did not vary with the time and trap height. Trifluralin concentrations of surface soil after four erosion events were higher (626.05 µg/kg) than wind-eroded soil (450.08 µg/kg). Keywords: Wind-eroded herbicide, trifluralin movement, QuEChERS method for soil.
Introduction Soils may contain several pesticide-like agro-chemicals through direct application, accidental spillage, run-off from plant surfaces or from incorporation of pesticide contaminated plant materials.[1,2] Among the different groups of pesticides, herbicides are more likely to pollute the soils. Phenylurea and urea herbicides are emerging ones with direct impacts on endocrine systems in recent years and they were already put into EU priority list of substances to be prevented.[3] Pesticides can move from treated agricultural lands into a broader environment through atmospheric means such as application drift, post-application vapor losses and winderoded soil.[4] Pesticides can either remain in the environment or move to some degree, may volatilize or erode from foliage or soil through wind erosion and then become airborne.[5] Wind erosion is a serious soil degradation problem along the semi-arid Canadian prairies. As well as removing valuable nutrients from the soil surface, wind erosion may also have the potential to transport herbicides. The movement of herbicides by water is well-documented, but few reports
Address correspondence to Osman Tiryaki, Department of Plant Protection, Faculty of Seyrani Agriculture, Erciyes University, Kayseri, Turkey; E-mail:
[email protected] Received February 27, 2012.
are concerned with herbicide transport in windblown sediment which may have off-farm impacts on water and air quality.[6] Gaynor and MacTavish[7] reported 43% simazine transport from a treated land by wind erosion over a sandy soil in Southwestern Ontario. Glotfelty et al.[8] also indicated atrazine, simazine and alachlor movement by wind erosion in Maryland. Recently, there has been much interest in the impact of wind erosion on off-site air quality and human health. A research study pointed out the potential hazards of transported herbicides in windblown sediment through inhalation on human health and through deposition on water quality.[9] Several monitoring studies have reported pesticide concentrations in rural and urban zones of different countries both in gas and particulate phases. Sofuoglu et al.[10] investigated the concentrations of 23 organochlorine pesticides in air and their gas/particle partitioning in Izmir, Turkey. Researchers observed average individual concentrations as between 5–391 pg m−3, with a pesticide percentage of up to 15% in particulate phase. Accurate and reliable methods for measuring windblown sediment are needed to confirm, validate, and improve erosion models; to assess the intensity of aeolian processes and related damage; to determine the source of pollutants. The type of sampling apparatus and methods to be used in wind erosion field studies depends basically on the specific objectives of the study.[11] The Big Spring Number Eight (BSNE) developed by Fryrear et al.[12], Modified Wilson and Cooke (MWAC) developed by Sterk et al.[13] and
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QuEChERS for trifluralin analysis sediment traps developed by Basaran et al.[14] appear to be the most popular ones for such objectives. Pesticide extraction from the soil, especially the extraction of bound residues, require stronger techniques like Soxhlet extraction, accelerated solvent extraction (ASE), pressurized liquid extraction (PLE), supercritical fluid extraction (SFE) and solid phase extraction (SPE). Such techniques are effective, but are either time-consuming or require the use of hazardous chemicals, expensive apparatus and consumables. Acetonitrile extraction method was proven to be very successful for extracting pesticides from plant samples. This technique, called QuEChERS (Quick, Easy, Cheap, Efficient, Rugged and Safe), has proved to be popular for extraction of pesticides for multi-residue methods.[2] In recent papers, Lesueur et al.[15] and Nagel[16] demonstrated that QuEChERS method offered a potential alternative technique for extraction of pesticide residues from soil samples. The researchers also compared a new ultrasonic solvent extraction (USE) with the QuEChERS method and a PLE method. In comparison, the QuEChERS method was found to be the most efficient extraction method with recoveries from 27.3 to 120.9%. The repeatability, expressed in terms of standard deviation, was below 20% for all substances and all materials.[15] Trifluralin is a pre-emergence, soil-incorporated herbicide that has been used in agriculture since the early 1960s. The use of trifluralin in Turkey is about 909.5 ton year−1. This herbicide is moderately persistent in soil. A study dealing with the movement of trifluralin revealed that trifluralin was generally located in the incorporation zone.[17] The objective of this study was to develop and validate a reliable analytical procedure for trifluralin herbicide analysis in wind-eroded sediments. Soil sediments trapped in BEST sediment catchers[14] were subjected to QuEChERS extraction method, incorporating a simple simultaneous cleanup step, followed by trifluralin analysis with GC-ECD. The reliability of analytical data and the validity of the method were also checked by method-performance criteria.[18–21]
Materials and methods Chemicals and reagents The standard 97.5% pure trifluralin was obtained from Dr. Ehrenstorfer Laboratories GmbH, Germany. Magnesium sulfate anhydrous, sodium chloride, tri-Sodium citrate dehydrate, petroleum benzene extra pure, acetonitrile (MeCN), ethylacetate (EtOAc) had purities of 98%, 99.5%, 99%, 75%, 99.8%, and 99.5%, respectively and they all were supplied from Merck. Bondesil- PSA and sodium hydrogencitrate sesquihydrate (>99%) were supplied from Varian and Aldrich, respectively.
Instrumentation The following equipment was used to perform this study: A centrifuge (Hettich Rotina 420 Centrifuge), centrifuge tube up to 50 mL capacity, balance with the 0.0001 g digit, Vortex (VELP scientifica), Agilent 6890 GC Plus equipped with auto sampler (7683 B Series) and capillary column (HP-5 MS, 30 m × 0.25 mm id × 0.25 µm nominal film thickness) connected through a ECD system, glass GC vials (Agilent technologies, 1.5 mL) N2 stream and other basic glassware and equipment. BEST sediment traps were also used in the study. Preparation of standard solution A standard stock solution was prepared by accurately weighing 10 + 0.01 mg of trifluralin in a volumetric flask and dissolving into it 25 mL EtOAc. This stock solution was stored in the dark at 4◦ C. An intermediate standard mixture of 10 µg mL−1 was prepared by mixing appropriate quantities of the stock solution and diluting accordingly. A working standard mixture of 1.0 µg mL−1 was prepared by diluting the intermediate standard solution, then the calibration standards within the range 12.5–150 ng mL−1 were prepared by serial dilution with EtOAc. Trifluralin fortification solution with the concentration of 0.5 µg mL−1 was also prepared in petroleum ether. Chromatographic conditions Dispersive-SPE cleaned up soil samples were subjected to GC-ECD, simultaneously applying 5-point calibration under the following conditions: capillary column (30.0 m × 250 µm id × 0.25 µm nominal film thickness, HP 19091S-433, HP-5MS 5% Phenyl Methyl Siloxane); carrier gas (He) 96.7 mL min−1, constant make up (nitrogen) 60 mL min−1. Operating Conditions; Column temperature: 60–220◦ C; initial time 2 min at 60◦ C; rise (I): 20◦ C min−1 to 120◦ C–5 min, rise (II): 5◦ C min−1 to 220◦ C–1 min, total run time: 31 min; detector temperature: 280◦ C, injector temperature: 250◦ C (splitless), injection volume: 2 µL. Trifluralin retention time was 24 min. Trifluralin residues in the soil are based on oven dry weights. Study site and herbicide application The 60 × 45 m experimental plot was plowed. Representative background soil samples were taken from 12 points, mixed and sub sampled. The experimental site was sprayed with trifluralin on March 18, 2011 and trifluralin was incorporated into a depth of 10 cm with a cultivator. Application rate was 2 kg a.i. ha−1 (twice as much of the recommended dose). Zero time soil samples from 0–10 cm depth were taken just after herbicide application. The initially applied dose was calculated by the analysis of zero-time samples. The results were evaluated in terms of a percentage of initially applied trifluralin.
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Fig. 1. Schematic overview of experimental site.
Sediments samplers and soil sampling
Fortification experiments (recovery tests)
Twenty poles of BEST wind erosion sediment samplers[14] were installed within the circular plot as described by Tiryaki et al.[22] immediately after herbicide incorporation. Each pole had five BEST traps mounted at 20, 40, 60, 80, and 100 cm above the soil surface. An overview of experimental site with sediment traps are presented in Figures 1 and 2. For four erosion events, sediment samples were collected from the traps between March 18 and 21 May, 2011. Since the amount of sediment trapped in each traps was not sufficient to proceed the analysis, samples were combined based on trap heights. Blank and zero time samples were also collected. Air-dried samples were passed through a 2 mm sieve and stored at room temperature. Soil losses, due to wind erosion, were calculated by the method of Ellis and Gulick.[23] The soil used in this study was sandy loam with a pH of 7.67, 1.01% organic matter, 13.06% clay, 12.09% silt and 74.85% sand.
Pesticide-free soil (blank) was spiked by using the following principles[15]: A 500 g sieved soil was spiked with 500 mL 0.5 µg mL−1 trifluralin standard solution (in petroleum ether), air-dried at room temperature for 7 days to obtain “aged soil” samples. Following the solvent evaporation, the materials were finally oven-dried overnight at 30◦ C. Sensitivity, recovery and precision of the methods were tested at 500 ng g−1 soil fortification level for 7 replicates in accordance with SANCO European Guideline.[24] The linearity of the methods was tested for 5 standards in EtOAc within the range of 12.5–150 ng mL−1. LOD and LOQ were assessed based on instrument and method detection limit approaches.
Fig. 2. Experiemental site with installed traps at 20, 45, 60, 80 and 100 cm above the soil surface (color figure available online).
Extraction and cleanup procedure The QuEChERS method described by Anastassiades et al.[25] and modified for soil samples by Lesueur et al.[15] was used in this study. A 10 g soil sample weighed into 40 mL centrifuge tube, 20 mL MeCN was added and samples were shaken vigorously for 1 min by using a Vortex mixer at maximum speed. The method was followed by salting-out step with 4 g MgSO4 , 1 g NaCl, 1 g sodium citrate dehydrate and 0.5 g di-sodium hydrogen citrate sesquihydrate. Later on, the sample was immediately mixed by a Vortex for 1 min to prevent formation of MgSO4 conglomerates. The extract was centrifuged for 10 min at 4500 rpm. The cleanup step of the samples was carried out by transferring aliquot of upper MeCN layer into 15 mL centrifuge tube containing 150 mg PSA sorbent and 900 mg MgSO4 [(25 mg PSA sorbent and 150 mg anhydrous MgSO4 )/mL extract]. The centrifuge tube was capped tightly and shaken with a Vortex mixer for 30 s. The extract centrifuged for 8 min at 4500 rpm. Since trifluralin standard will be injected in EtOAc solution in GC system,[26] final extract solvent should be exchanged to EtOAc. The procedure was as follows:[27] 5 mL of the extract was transferred from second centrifuged
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QuEChERS for trifluralin analysis Sampled soil from the BEST Traps
Fortified soil (500 ng/g) sample
Add 20 mL MeCN
Extraction
Salting with 4 g MgSO4, 1 g NaCl, 1 g Sodium citrate dihydrate and 0.5 g di-sodium hydrogen citrate Mix by Vortex, 1 min Centrifuge 10 min, at 4500 rpm
Clean up
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Shake with Vortex, 1 min
Transfer supernatant into centrifuge tube containing 150 mg PSA and 900 mg MgSO4
Add 5 mL extract to tube Add 1 mL EtOAc Evaporate extract to 0.3-0.5 mL with N2 Adjust to 1 mL, with EtOAc
Add 150 mg MgSO4
Solvent changing
10 g soil
Mix by Vortex Centrifuge 5 min, at 4500 rpm
Transfer 1.5 mL extract to GC vials
GC-ECD Analysis
Sample preparation (removing large items)
Centirfuge 8 min, at 4500 rpm
Fig. 3. The schematic presentation of QuEChERS method for the analysis of trifluralin in soil samples.
extract to a 15 mL graduated tube, and 1 mL EtOAc was added. The extract was evaporated to 0.3-0.5 mL using 7.5 psi N2 flow and brought the extracts to 1.0 mL with EtOAc again, then 150 mg anhydrous MgSO4 was added to remove any residual water. The tubes were vortexed to rinse the walls above the 6 mL mark. It was centrifuged for 5 min at 4500 rpm. Final extract may still contain MeCN, thus precautions should be taken (e.g. solvent venting) prior to conducting GC-ECD analysis. Finally, 1.5 mL extract was transferred to GC vial. Figure 3 illustrates schematic flow chart of the entire analytical method. Matrix effect and matrix matched calibration The matrix effect (ME) was assessed by employing matrixmatched standards. The slope of the calibration graph based on the matrix-matched standards of soil extract was
compared with the slope of the pure solvent-based calibration graph. A higher slope of the matrix calibration indicates matrix-induced signal enhancement, whereas a lower slope represents signal suppression. The percent of ME was evaluated by Equation 1.[18] The negative and positive values of the ME signify matrix-induced suppression and enhancement, respectively. ME, % = (peak area of matrix standard − peak area of solvent standard) × 100 (1) peak area of solvent standard
Matrix-matched calibration standards were prepared with blank extract and trifluralin standard at 5 different concentrations as of 12.5, 25, 50, 100 and 150 ng mL−1. Calibrations were based on representative sample equivalent amount.
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Table 1. Calibration parameters for the trifluralin for GC-ECD detection with five-level calibration, in solvent and sample matrix. Linear range, ng/mL
Calibration and/or analytic function,a y = a + bx
Calibration in solvent 12.5–150 y = 9.831851+ 3.86661x Calibration in sample matrix (0.45 g/mL seq) 12.5–150 y = 21.52954+3.025933x Calibration in sample matrix (0.91 g/mL seq) 12.5–150 y = 36.25894+2.693023x Calibration in sample matrix (3.64 g/mL seq) 12.5–150 y = 39.89038+2.338246x Calibration in sample matrix (10 g/mL seq) 12.5–150 y = 28.83885+1.580462x
Correlation coefficient, R
Relative residual standard deviation, Sy/ˆy
0.999626
0.091683
0.994962
0.098509
0.996094
0.097912
0.994809
0.095984
0.998475
0.099325
x = injected amount to GC; y = ECD detector response as area.
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a
Method validation
Estimated Method Detection Limit (EMDL)
The analytical method was validated in accordance with the single laboratory validation approach.[28] The performance of the method was evaluated by considering different validation parameters.[18] The calibration curves of trifluralin in pure solvent and matrix were obtained by plotting the peak area against the concentration of the corresponding calibration standards at 5 calibration levels ranging between 12.5–150 ng mL−1 (Table 1).
The estimated method detection limit is defined as the approximate minimum concentration of a pesticide that can be determined from a particular matrix by a particular method. It depends upon the recovery of pesticide by the given method and can be different for different matrices. For recovery, blanks of un-spiked vegetables were used to compare the results. The EMDLs were estimated from the IDLs as follows (Equation 3).[19,20] EMDL (µg g−1 ) =
Limits of Detection (LOD) and Limit of Quantification (LOQ) The LOD is generally determined by considering a signalto-noise ratio of 3 with reference to the background noise obtained from blank sample, whereas the LOQ were determined by considering a signal-to-noise ratio of 10 by using matrix-matched standards. LOD is also estimated through standard deviation of peak areas of 10 repetitive injections of a standard solution. These values show only instrument or equipment detection limit. But the whole method LOD includes several steps from sample homogenization to chromatographic analysis. Therefore, instrument limit and estimated method detection limit should be evaluated separately. Instrument Detection Limit (IDL) The IDL is generally defined as the minimum concentration of pure pesticide solution that can be reliably detected by the chromatographic system. The IDLs for trifluralin was estimated through 10 repetitive injections of 300 pg µL−1 standard solution by using Equation 2.[19,20] IDL (µg mL−1 ) = SD × t95
(2)
Where, SD is the standard deviation of the peak areas for the replicate injections, and t95 is the Student’s t at the 95% level of confidence.
IDL × 100 × V M × Rec %
(3)
with M being the mass of sample (g) and Rec % is the average recovery of the pesticide.
Results and discussion Method performance and method validation linearity Linearity was assessed by using matrix-matched calibration and solvent calibration. The curves of trifluralin was linear over the range 12.5–150 ng mL−1 (Table 1). The linearity of all 5 calibration curves were determined by computing r and Sy/ˆy values. The r values were > 0.99 for all calibrations, the calculated Sy/ˆy values calculated by using Equation 4 were less than the required limit of 0.1.[29–31] sy/ yˆ =
¯ 2 (Yi − Y) n−2
(4)
Where; yi is the response obtained from injecting standard, yˆ i is the point corresponding to standard on the regression line, Y¯ is the mean value of Yi , n is the number of injections.
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QuEChERS for trifluralin analysis Chromatographic repeatability The repeatability of retention time was assessed by using matrix matched calibration solutions.[2] The retention time of trifluralin ranged between 24.164 and 24.168 min with the relative standard deviation (RSD,%) of 0.49% (n = 20). LOD and LOQ IDL and EMDL were calculated in accordance with to Singh et al.[19,20] as 9.47 µg mL−1 and 11.41 µg g−1, respectively in present study.
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Matrix effect Since trifluralin exhibited ME, matrix-matched standard calibration and internal standard methodology were used for quantitative analysis. The ME was evaluated with the above mentioned Equation 1[18] and found as 25.49%. Figures 4 and 5 also illustrate differences of trifluralin standard response in solvent and matrix-matched standard of GCECD system.
These findings comply with the values specified for mean recovery range (70–120%) and repeatability (RSD ≤ 20%).[32] Calculation of trifluralin loss The amount of trifluralin lost in wind-eroded sediment during a wind-erosion event was calculated as the product of the total mass of sediment lost and the mean trifluralin concentration (µg kg−1) in the sediment load across all trap heights. To find out initially applied trifluralin amount, zero time soil samples were analyzed and initial amount was found to be 1313.39 ng g−1. Whereas, with the application rate of 2 kg a i ha−1, applied amount of herbicide is expected to be 1563 ng g−1 to supply a total amount of 540 g to research plot. Therefore herbicide application performance was determined as 84.03%. The percentage of moved trifluralin was calculated based on initially applied dose. Mean moved trifluralin concentration was 450.08 ng g−1. This concentration was equal to 34.27% of the initially applied concentration. Trifluralin concentrations in wind-eroded sediment
Recovery and precision The analyses of 7 replicate-spiked (500 ng g−1) soil samples were performed in GC-ECD system, then evaluated by using calibration in sample matrix (0.91 g mL−1 sample equivalent). The analytical function of y = 36.25894+2.693023x was used for calculation (Table 1). Recovered trifluralin ranged between 87.18 - 93.94% with a median recovery of 91.32%. The repeatability value was determined as 3.15%.
Four erosion events were monitored between March 18 and May 21, 2011 and the total soil loss was found to be 0.672 t ha−1[22] corresponding to 0.302 g trifluralin ha−1. Trifluralin was detected in all sediment samples regardless of sampler height. Trifluralin concentrations at different trap heights were presented in Figure 6. Concentrations of the herbicide in the wind-eroded sediment ranged between 425.66-472.41 µg kg−1 with a mean value of 450.08 µg kg−1. There was no effect of trap height on trifluralin
Fig. 4. Chromatogram of trifluralin (Rt = 24.166 min) in solvent (100 pg/µL) (color figure available online).
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Fig. 5. Chromatogram of trifluralin (Rt = 24.166 min) in matrix (100 pg/µL) (color figure available online).
concentration in any of the wind erosion events. Similarly, there was no difference among the four erosion events with regard to trifluralin concentrations. Although increasing trifluralin concentrations would be expected in winderoded sediment with increasing sampler height, Larney et al.[6] reported no significant effect of trap height on sediment concentrations of trifluralin incorporated into a clay loam soil. But, Cessna et al.[33] observed the significant interactions between trap height and trifluralin concentrations. Several factors such as meteorological conditions, soil type, photodegradation and vapor losses may have led to such differences.
The trifluralin concentration of the surface soil after four erosion events was higher (626.05 µg kg−1) than winderoded soil (450.08 µg kg−1). Similar observations were also reported by Cessna et al.[33] Sediment sample mass, consequently trifluralin amount, generally decreased with increasing sampler height. The mean amount of trifluralin collected from Best traps through 2 × 2 cm square inlet were 3.35, 0.81, 0.44, 0.42 and 0.33 µg for 20, 40, 60, 80, and 100 cm sampler heights. Overall trifluralin losses on wind-eroded sediment were also assessed. Combining soil loss values of each trap height, the estimated herbicide losses for erosion Event 1,
Fig. 6. Ttrifluralin concentration at different heights. Same letters indicate insignificant differences (P = 0.05), bars represent standard errors of the means.
Fig. 7. Trifluralin loss in different erosion events. Bars represent standard errors of the means.
QuEChERS for trifluralin analysis Event 2, Event 3 and Event 4 were determined as 24.23, 9.71, 35.73, 12.10 mg, respectively, with a total estimated loss of 81.77 mg (Fig. 7). This was equivalent to 0.018% of initially applied trifluralin. This loss differs from the values reported by Larney et al.[6] and Cessna et al.[33] Several factors such as precipitation, soil type, photodegradation, vapor losses and microbial degradation may have contributed to this difference.
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Conclusion The objectives of the current research were successfully met through QuEChERS extraction method, incorporating a simple simultaneous cleanup and concentration step, followed by GC-ECD. This study revealed that following incorporation of trifluralin into sandy loam agricultural soil, trifluralin concentrations in the wind-eroded sediment did not vary with time after incorporation, and did not increase with trap height. Similar findings have been reported earlier by Larney et al.[6] and Cessna et al.[33] Since the herbicide was soil-incorporated, its presence in the sediment regardless of the time interval between application and the erosion event is most likely due to the upward movement of trifluralin toward the soil surface. Since trifluralin was incorporated into 10 cm upper soil layer through plowing, total concentration was diluted within 10 cm layer. On the other hand, surface-applied herbicides are adsorbed by soil particles of upper shallow surface layer which is the most prone layer to wind erosion. Hence the potential for removal of surface-applied chemicals by wind erosion is much higher than the soilincorporated herbicides. Also, the concentrations were significantly higher in the surface soil (0–2.5 cm) than in the wind-eroded sediment, whereas concentrations of surfaceapplied herbicides were generally higher in wind-eroded sediment than in surface soil.[6] These two observations support the findings of current study.
Acknowledgments This work was supported by the Scientific Research Project Foundation of Erciyes University, under the project no. of FBA-10-2886.
References [1] Getenga, Z.M.; Keng’ara, F.O.; Wandiga, S.O. Determination of organochlorine pesticide residues in soil and water from river nyando drainage system within Lake Victoria Basin, Kenya. Bull. Environ. Contam. Toxicol. 2004, 72, 335–343. [2] Rashid, A.; Nawaz, S.; Barker, H.; Ahmad, I.; Ashraf, M. Development of a simple extraction and clean-up procedure for determination of organochlorine pesticides in soil using gas chromatographytandem mass spectrometry. Journal of Chromatography A. 2010, 1217, 2933–2939.
849 [3] Commission of the European Communities. EU Water Framework Directive, Directive 2000/60/EC; CEC:, Brussels, Belgium, 2000. [4] Cessna, A.J.; Allan, J. Pesticides in the environment: Real or Imagined. Agriculture and Agri-food Canada, Research Centre: Lethbridge, AB; 2009. Available at http://www.ssca.ca/ conference/conference2005/Cessna.pdf (retrieved January 2012). [5] Kerle, E.A.; Jenkins, J.J.; Vogue, P.A. Understanding pesticide persistence and mobility for groundwater and surface water protection; EM8561-E; Oregon State Univ. Extension Service: Corvallis, OR, 2007. [6] Larney, F.J.; Cessna, A.J.; Bullock, M.S. Herbicide transport on wind-eroded sediment. J. Environ. Qual. 1999, 28, 1412–1421. [7] Gaynor, J.D.; MacTavish, D.C. Movement of granular simazine by wind erosion. HortScience 1981, 16, 756–757. [8] Glotfelty, D.E.; Leech, M.E.; Jersey, J.; Taylor, A.W. Volatilization and wind erosion of soil surface applied atrazine, simazine, alachlor and toxaphene. J. Agric. Food Chem. 1989, 37, 546–551. [9] Saxton, K.E. Wind erosion and its impact on off-site air quality in the Columbia Plateau—an integrated research plan. Trans. ASAE. 1995, 38, 1031–1038. [10] Sofuoglu, A.; Cetin, E.; Bozacioglu, S.S. Short-term variation in ambient concentrations and gas\particle partitioning of organochlorine pesticides in Izmir, Turkey. Atmospheric Environment 2004, 38, 4483–4493. [11] Zobeck, T.M.; Van Pelt, R.S. Wind induced dust generation and transport mechanics on a bare agricultural field. Journal of Hazardous Materials. 2006, 132, 26–38. [12] Fryrear, D.W.; Stout, J.E.; Hagen, L.J.; Vories, E.D. Wind erosion: field measurement and analysis. Trans. ASAE 1991, 34, 155–160. [13] Sterk, G.; Lopez, M.V.; Arrue, J.L. Saltation transport on a silt loam soil in northeast Spain. Land Degradation and Development 1999, 10, 545–554. [14] Basaran, M.; Erpul, G.; Uzun, O.; Gabriels, D. Comparative efficiency testing for a newly designed cyclone type sediment trap for wind erosion measurements. Geomorphology 2011, 130(3–4), 343–351. [15] Lesueur, C.; Gartner, M.; Mentler, A.; Fuerhacker, M. Comparison of four extraction methods for the analysis of 24 pesticides in soil samples with gas chromatography–mass spectrometry and liquid chromatography-ion trap-mass spectrometry. Talanta 2008, 75, 284. [16] Nagel, T.G. The QuEChERS Method - A new Approach in Pesticide Analysis of Soils, 2009. Available at http://www.usabtm.ro/Journal-HFB/romana/Lucrari 2009 paginate/89.pdf (retrieved February 2012). ¨ [17] Tiryaki, O.; Gozek, K.; Khan, S.U. 14C-residues of trifluralin in a soil and their uptake by carrots. Bull. of Environ. Contamination and Toxicology. 1997, 59(1), 58–64. [18] Kanrar, B.; Mandal, S.; Bhattacharyya, A. Validation and uncertainty analysis of a multiresidue method for 42 pesticides in made tea, tea infusion and spent leaves using ethyl acetate extraction and liquid chromatography-tandem mass spectrometry. Journal of Chromatography A 2010, 1217, 1926–1933. [19] Singh, S.B.; Foster, G.D.; Khan, S.U. Microwave-assisted extraction for the simultaneous determination of thiamethoxam, ımidacloprid, and carbendazim residues in fresh and cooked vegetable samples. J. Agric. Food Chem. 2004, 52, 105–109. [20] Singh, S.B.; Foster, G.D.; Khan, S.U. Determination of thiophanate methyl and carbendazim residues in vegetable samples using microwave-assisted extraction. Journal of Chromatography A 2007, 1148, 152–157. [21] Tiryaki, O.; Baysoyu, D.; Sec¸er, E.; Aydın, G. Testing the stability of pesticides during sample processing for the chlorpyrifos and malathion residue analysis in cucumber, including matrix effects. Bull. of Environ. Contam. Toxicol. 2008, 80(1), 38–43. [22] Tiryaki, O.; Basaran, M.; Uzun, O.; Temur, C.; Horuz, S. Investigation of herbicide transport in windblown soil after the trifluralin application in Konya Karapınar Plain. Unpublished data;
850
[23]
[24]
[25]
[26]
Downloaded by [Erciyes University] at 07:58 09 February 2015
[27]
Temur et al. Scientific Research Project Fund of Erciyes University (Project Code: FBA-10-2886), 2012. Ellis, R.; Gulick, D. Calculus, One and Several Variables; Saunders College Publishing, Harcourt Brace Javonovich College Publishers, USA, 1991. European Union Guidelines for Quality control procedures for pesticide residue analysis, EU Document No SANCO/10232/ 2006, March 24, 2006. ˇ Anastassiades, M.; Lehotay, S.J.; Stajnbaher, D.; Schenck, F.J. Fast and easy multiresidue method employing acetonitrile extraction/partitioning and dispersive solid-phase extraction for the determination of pesticide residues in produce. Journal of AOAC International. 2003, 86(2), 412–431. Mamun, M.I.; Park, J.H.; Choi, J.H.; Kim, H.K.; Choi, W.J.; Han, S.S.; Hwang, K.; Jang, N.I.; Assayed, M.E.; El-Dib, M.A.; Shin, H.C.; Abd El-Aty, A.M.; Shim, J.H. Development and validation of a multiresidue method for determination of 82 pesticides in water using GC. J. Sep. Sci. 2009, 32, 559–574. Lehotay, S.J.; Mastovsk´a, K.; Lightfield, A.R. Use of buffering and other means to improve results of problematic pesticides in a fast and easy method for residue analysis of fruits and vegetables. Journal of AOAC International. 2005, 88(2): 615–629.
[28] Thompson, M.; Ellison, S.L.R.; Wood, R. Harmonized guidelines for single laboratory validation of methods of analysis. Pure Appl. Chem. 2002, 74(5): 835–855. [29] Huber, W. On the use of the correlation coefficient r for testing the linearity of calibration functions. Accred Qual Assur. 2004, 9, 726. [30] Miller, J.N.; Ambrus, A. Significance Test 1, Statistics in Calibration Analysis, I and II. Manual on Basic Statistics. In Lectures Database, FAO/IAEA Workshop on Introduction to QC/QA Measures in Pesticide Residue Analytical Laboratories, Seibersdorf, Vienna, Austria, September 12– October 7, 2005. [31] Tiryaki, O. Method validation for the analysis of pesticide residues in grain by thin-layer chromatography. Accreditation and Quality Assurance 2006, 11(10), 506–514. [32] SANCO. European Union Guidelines for Method validation and quality control procedures for pesticide residues analysis in food and feed, Document No. SANCO/10684/2009, 2009. Available at http://ec.europa.edu/food/plant/protection/resources/ qualcontrol en.pdf (retrieved January 2012). [33] Cessna, A.J.; Larney, F.J.; Kerr, L.A.; Bullock, M.S. Transport of trifluralin on wind-eroded sediment. Canadian Journal of Soil Science May 2006, 86(3): 545–554.
