Progress 10/01/03 to 09/30/08
Outputs
OUTPUTS: An inter-laboratory study was conducted at 8 locations to assess the stability of pesticides on solid-phase extraction (SPE) disks after incubation at various temperatures and for various time intervals. Deionized water fortified with selected pesticides was extracted by using 2 types of SPE filtration disks (Empore C18 and Speedisk C18XF), and after extraction, the disks were incubated at 3 temperatures (25, 40, and 55_C) and for 2 time intervals (4 and 14 days). Deionized water was fortified with atrazine, carbofuran, and chlorpyrifos by all participating laboratories. In addition, some of the laboratories included 2 of the following pesticides: metolachlor, metribuzin, simazine, chlorothalonil, and malathion. Concurrently, fortified water samples were extracted with the incubated samples by using each disk type at 4 and 14 days. Pesticides had equivalent or greater stability on _1 of the C18 disk types, compared with storage in water. The lowest recoveries of carbofuran (6%) and chlorpyrifos (7%) were obtained at 55_C after storage for 14 days in incubated water. At 55_C after 14 days, the lowest recovery for atrazine was 65% obtained by using Empore disks. Pesticide-specific losses occurred on the C18 disks in this study, underlining the importance of temperature and time interval when water is extracted at remote field locations and the SPE disks containing the extracted pesticides are transported or shipped to a laboratory for elution and analysis. PARTICIPANTS: Not relevant to this project. TARGET AUDIENCES: Not relevant to this project. PROJECT MODIFICATIONS: Not relevant to this project.
Impacts
As pesticides are used, some of them may end up in non-target areas where we do not want them, including rivers and streams. This project developed new chemical analytical methods to find how much pesticide was remaining in the surface water, so that we can then use that information for safety evaluations. Since many people get their drinking water from surface supplies (rivers and lakes) it is important to know how much pesticide (if any) is in the water.
Publications
- Mueller, T.C, T. A. Ellis, J. E. Beeler, S. D. Sharma and M. Singh. 2008. Shikimate Accumulation in Nine Weedy Species Following Glyphosate Application. Weed Research 48:455-460.
- Mueller, T. K. Roy, D. Ghosh, and M. Radosevich. 2008. Atrazine-Degrading Microbial Populations in Soils. Proc. International Weed Sci. Congress 5:234.
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Progress 01/01/07 to 12/31/07
Outputs
Regional project that is nearing completion in 2008. Final report to be prepared in 2008.
Impacts
The application of these procedures will allow for pesticide extraction at remote locations with confidence for environmental sampling.
Publications
- Ohmes, G. A. and T. C. Mueller. 2007. Sulfentrazone Adsorption and Mobility in Surface Soil of the Southern United States. Weed Technol. 21:796-800.
- Mueller, T., A. Ellis, J. Beeler, S. Sharma, and M. Singh. 2007. Shikimate accumulation in nine weedy species following glyphosate application. Proc. European Weed Research Society 14:61.
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Progress 01/01/06 to 12/31/06
Outputs
An interlaboratory study was conducted at 8 locations to assess the stability of pesticides on solid-phase extraction (SPE) disks after incubation at various temperatures and for various time intervals. Deionized water fortified with selected pesticides was extracted by using 2 types of SPE filtration disks (Empore C18 and Speedisk C18XF), and after extraction, the disks were incubated at 3 temperatures (25, 40, and 55_C) and for 2 time intervals (4 and 14 days). Deionized water was fortified with atrazine, carbofuran, and chlorpyrifos by all participating laboratories. In addition, some of the laboratories included 2 of the following pesticides: metolachlor, metribuzin, simazine, chlorothalonil, and malathion. Concurrently, fortified water samples were extracted with the incubated samples by using each disk type at 4 and 14 days. Pesticides had equivalent or greater stability on _1 of the C18 disk types, compared with storage in water. The lowest recoveries of
carbofuran (6 percent) and chlorpyrifos (7 percent) were obtained at 55_C after storage for 14 days in incubated water. At 55_C after 14 days, the lowest recovery for atrazine was 65 percent obtained by using Empore disks. Pesticide-specific losses occurred on the C18 disks in this study, underlining the importance of temperature and time interval when water is extracted at remote field locations and the SPE disks containing the extracted pesticides are transported or shipped to a laboratory for elution and analysis.
Impacts
The application of these procedures will allow for pesticide extraction at remote locations with confidence for environmental sampling.
Publications
- Cobb, J. M., J. D. Mattice, S. A Senseman, J. A. Dumas, W. Mersie, M. B. Riley, T. L. Potter, T. C. Mueller, and E. B. Watson. 2006. Stability of Pesticides on Solid-Phase Extraction Disks after Incubation at Various Temperatures and for Various Time Intervals: Interlaboratory Study. J. Assoc. Of Official. Analytical Chem. 89:903-912.
- Mersie, W., Riley, M. B.,Dumas, J. A., Gbur, E. E., Massey, J. H., Mattice, J. D.,Mueller, T. C., Potter, T.,Senseman, S. A. and Watson, E. 2006. Pesticide Extraction Efficiency of Two Solid Phase Disk Types after Shipping. Abs Weed Sci. Soc. Amer. 46:43.
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Progress 01/01/05 to 12/31/05
Outputs
An interlaboratory study was conducted to compare pesticide recovery of Empore C18 solid phase extraction disks and SpeedisksTM C18XF. Four pesticides were used for the comparison of the two disk extraction materials: atrazine, diazinon, metolachlor, and tebuconzole. These pesticides were chosen to provide a range of physicochemical properties. Water samples were extracted onto the disk types and shipped to a cooperating laboratory for elution and analysis. Mean recovery from Empore disks was atrazine:94.6 percent, diazinon:90.7 percent, metolachlor 92.2 percent and tebuconazole 83.1 percent while recovery from Speedisks TM C18XF was atrazine:88.7 percent, diazinon:86.5 percent, metolachlor 85.5 percent and tebuconazole 78.6 percent. Means were not statistically different, but there was more variability with Speedisks TM C18XF compared to Empore disks. Results indicate that SpeedisksTM C18XF could be used as an alternative to Empore disks with no significant losses in
recovery. SpeedisksTM C18XF are enclosed in a plastic housing so they can be used more easily in remote sampling sites.
Impacts
The overall results of this study indicate that the SpeedisksTM can provide equivalent pesticide recovery when compared to EmporeTM disks. The SpeedisksTM may provide more flexibility when extracting pesticides from water samples in a field situation since they require none of the glassware associated with the normal extraction manifold used with EmporeTM disks. The application of these procedures will allow for pesticide extraction to be conducted at any site worldwide without having the expense of shipping water samples to analytical laboratories.
Publications
- Riley, M. B., J. A. Dumas, E. E. Gbur, J. H. Massey, J. D. Mattice, W. Mersie, T. C. Mueller, T. Potter, S. A. Senseman, and E. Watson. 2005. Pesticide Extraction Efficiency of two Solid Phase Extraction Disk Types after Extraction and Shipping. J. Agric & Food Chem. 53:5079-5083.
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Progress 01/01/04 to 12/31/04
Outputs
An interlaboratory study was conducted to compare pesticide recovery of Empore TM C18 solid-phase extraction disks and Speedisks TM C18XF. Four pesticides were used for the comparison of the two disk extraction materials: atrazine, diazinon, metolachlor, and tebuconzole. These pesticides were chosen to provide a range of physicochemical properties. Water samples were extracted onto the disk types and shipped to a cooperating laboratory for elution and analysis. Mean recovery from Empore TM disks was atrazine:94.6%, diazinon:90.7%, metolachlor 92.2% and tebuconazole 83.1% while recovery from Speedisks TM C18XF was atrazine:88.7%, diazinon:86.5%, metolachlor 85.5% and tebuconazole 78.6%. Means were not statistically different, but there was more variability with Speedisks TM C18XF compared to Empore disks. Results indicate that Speedisks TM C18XF could be used as an alternative to Empore disks with no significant losses in recovery. Speedisks TM C18XF are enclosed in a
plastic housing so they can be used more easily in remote sampling sites.
Impacts
The overall results of this study indicate that the Speedisks TM can provide equivalent pesticide recovery when compared to Empore TM disks. The Speedisks TM may provide more flexibility when extracting pesticides from water samples in a field situation since they require none of the glassware associated with the normal extraction manifold used with EmporeTM disks. The application of these procedures will allow for pesticide extraction to be conducted at any site worldwide without having the expense of shipping water samples to analytical laboratories.
Publications
- No publications reported this period
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