Vapor pressures of sulfonylurea herbicides |
| |
| Authors: | Margaret E Schmuckler Aldos C Barefoot Daniel A Kleier Daryl P Cobranchi |
| |
| Abstract: | Vapor pressure values for agricultural chemicals are necessary for estimating volatilization and dissipation through transport in the vapor phase. The low vapor pressures of the sulfonylurea herbicides have presented significant challenges in vapor pressure determination. We have used the Knudsen gas effusion method at elevated temperatures and extrapolated to 25 °C. Along with the Knudsen method, computer calculations using the Grain equation were also used to estimate vapor pressure. The gas saturation method with quantitation by high performance liquid chromatography (HPLC) provided an upper limit that confirmed the low vapor pressures obtained using Knudsen gas effusion and computer calculations. We report the best available experimental results for the vapor pressures of sulfonylurea herbicides. © 2000 Society of Chemical Industry |
| |
| Keywords: | sulfonylurea vapor pressure Knudsen gas saturation calculation Grain equation |
|
