Evaluation of a gas chromatographic method calculating vapor pressures with organophosphorus pesticides

Kim, Yong‐Hwa; Woodrow, James E.; Seiber, James N.

doi:10.1016/s0021-9673(01)97721-0

Cited by 55 publications

(60 citation statements)

References 10 publications

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“…Although, vapor pressure is a key parameter for most environmental fate predictive models, only few data concerning the less volatile system have been reported in the literature. 15 For alkyl phosphates and alkyl phosphonates, several values of vapor pressure at ambient temperature disagree by an order of magnitude or more and except molecules such as TBP, 16 the temperature dependence of the vapor pressure has not been studied. For these reasons, the evolution of the vapor pressures of DMMP, TMP, TEP, and TBP have been measured from room temperature to the boiling point using the static head-space gasphase chromatography (HS-GC) experimental procedure described previously.…”

Section: Methodsmentioning

confidence: 99%

Gas-Phase Vibrational Spectroscopy and Ab Initio Study of Organophosphorous Compounds: Discrimination between Species and Conformers

et al. 2008

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Gas phase vibrational spectra of dimethyl methylphosphonate (DMMP), trimethyl phosphate (TMP), and triethyl phosphate (TEP) have been measured using FTIR spectroscopy. For DMMP, TMP, and TEP, most of the infrared active vibrational modes have been observed in the 50-5000 cm (-1) spectral range, allowing an unambiguous discrimination between the three molecules. The vibrational analysis of the spectra was performed by comparing with MP2 and B3LYP harmonic and anharmonic force field ab initio calculations. The extension to anharmonic calculations provides the best agreement for the mid-infrared and the near-infrared spectra, but they do not improve the harmonic frequency predictions in the far-infrared domain. This part of the vibrational spectra associated with collective and nonlocalized vibrational modes presents the largest frequency differences between the two lowest energy conformers of DMMP and TMP. These two conformers were taken into account in the vibrational assignment of the spectra. Their experimental evidence was obtained by deconvoluting vibrational bands in the mid-infrared and in the far-infrared regions, respectively. For TEP, the conformational landscape appears very complicated at ambient temperature, and a further analysis at low temperature is required to explain the vibrational features of each conformer.

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Section: Methodsmentioning

confidence: 99%

Gas-Phase Vibrational Spectroscopy and Ab Initio Study of Organophosphorous Compounds: Discrimination between Species and Conformers

et al. 2008

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“…This unit was designed by the manufacturer to provide an intensity of 1 sun over a 20-cm-diameter circular target. To verify the collimated light intensity, a fixed-wavelength Spectroline DM-300N UVB ultraviolet meter was used to estimate spatial distribution of 290-310-nm intensity from the top of the chamber to its base, a distance of 1 m. To minimize back-reflection of light at the (Kim, 1985). anterior end of the chamber, the light was trapped by a darkened surface.…”

Section: Chemicalsmentioning

confidence: 99%

Use of Stable Tracer Studies To Evaluate Pesticide Photolysis at Elevated Temperatures

Hebert

Hoonhout

Miller

2000

J. Agric. Food Chem.

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New methods were developed to determine photolysis rates of medium-weight pesticides in the gas phase using elevated air temperatures and solid-phase microextraction (SPME). A 57-L glass chamber was constructed that utilized collimated xenon arc irradiation that could heat chamber air to increase the amount of pesticide in the gas phase. Gas-phase photolysis rates were determined at various air temperatures by comparing the rate of loss of each of the tested pesticides to a photochemically stable tracer, hexachlorobenzene. Interval sampling of gas-phase constituents was performed using SPME immediately followed by GC-ECD or GC-MSD analysis. The two pesticides under examination were the dinitroaniline herbicide trifluralin and the organophosphorus insecticide chlorpyrifos. The gas-phase photolysis for trifluralin was found to be rapid with half-lives of 22-24 min corrected for sunlight. These results were comparable to photochemical lifetime estimates from other investigators under sunlight conditions. Elevating temperatures from 60 to 80 degrees C did not affect photolysis rates, and these rates could be extrapolated to environmental temperatures. From 60 to 80 degrees C, gas-phase chlorpyrifos photolysis lifetimes were observed to range from 1.4 to 2.2 h corrected for sunlight and will thus be important together with hydroxyl radical reactions for removing this substance from the atmosphere. At these elevated temperatures, pesticides and tracer compounds were found to be substantially in the gas phase, and possible effects on reaction rates from wall interactions were minimized.

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“…To determine the usefulness of these studies for criteria derivation, they were subjected to a review process, depending on the type of study; the three types were (1) single-species effects, (2) ecosystem-level studies, and (3) terrestrial wildlife studies. d Hummel and Crummet (1964), Felsot and Dahm (1979), and Drummond (1986) e Bowman and Sans (1983a), Brust (1964Brust ( , 1966, McDonald et al (1985), and Rigertink and Kenaga (1966) f Brust (1964), McDonald et al (1985), and Chakrabarti and Gennrich (1987) g Wu et al (2002), Fendinger and Glotfelty (1990), and Downey (1987) h Racke (1993) and Spieszalski et al (1994) i Sangster Research Laboratories (2004) j Worthing (1991) k Martin and Worthing (1977), Jarvinen and Tanner (1982), Kanazawa (1981), and Bowman andSans (1979, 1983b) l Kim et al (1984) and Hinckley et al (1990) m …”

Section: Data Collection and Evaluationmentioning

confidence: 99%

Aquatic Life Water Quality Criteria for Selected Pesticides

Tjeerdema¹

2012

Reviews of Environmental Contamination and Toxicology

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Evaluation of a gas chromatographic method calculating vapor pressures with organophosphorus pesticides

Cited by 55 publications

References 10 publications

Gas-Phase Vibrational Spectroscopy and Ab Initio Study of Organophosphorous Compounds: Discrimination between Species and Conformers

Gas-Phase Vibrational Spectroscopy and Ab Initio Study of Organophosphorous Compounds: Discrimination between Species and Conformers

Use of Stable Tracer Studies To Evaluate Pesticide Photolysis at Elevated Temperatures

Aquatic Life Water Quality Criteria for Selected Pesticides

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