Toxaphene Insecticide: A Complex Biodegradable Mixture

Casida, John E.; Holmstead, Roy L.; Khalifa, Safy; Knox, John R.; Ohsawa, Tomihiko; Palmer, Kenneth J.; Wong, Rosalind Y.

doi:10.1126/science.183.4124.520

Cited by 98 publications

(54 citation statements)

References 4 publications

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“…Toxaphene is a complex mixture primarily consisting of chlorinated bornanes (CHBs) with an average elemental composition of C 10H10Cl8 (1)(2)(3). Prior to its ban in 1982 by the U.S. Environmental Protection Agency (1), toxaphene was the most extensively used pesticide in the United States and many parts of the world.…”

Section: Introductionmentioning

confidence: 99%

Multidimensional Gas Chromatographic Analysis of Toxaphene

Boer¹,

Geus²,

Brinkman³

1997

Environ. Sci. Technol.

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The pesticide toxaphene with a total worldwide production of 1.3 Mt is found in the aquatic environment with a widespread, global distribution. Its analysis is difficult due to its complex character. A technical toxaphene mixture and a number of biological samples were analyzed by multidimensional gas chromatography (MDGC). Four different column combinations were used: DB5/DX4, DB5/FFAP, Ultra 2/DX4, and Ultra 2/Rtx 2330. The technical mixture consists of at least 246 congeners, while only 107 peaks were found in a one-dimensional GC/ECD chromatogram. The major peaks present in the technical mixture and biological samples mostly consist of 2-10 toxaphene congeners. These results show that in most cases single-column chromatography is not suitable for a congener-specific determination of the toxaphene congeners. The Rtx 2330 column is recommended as the best choice as a second column in MDGC of toxaphene, particularly because of its stability at higher temperatures and because of a slightly better separation, although the differences in results obtained with the different column combinations were relatively small. The relatively high concentrations of toxaphene in European fish, which may even lead to exceeding the tolerance levels for human consumption, and in marine mammals demand a proper monitoring of total toxaphene and individual CHBs in relevant samples from European aquatic ecosystems.

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Section: Introductionmentioning

confidence: 99%

Multidimensional Gas Chromatographic Analysis of Toxaphene

Boer¹,

Geus²,

Brinkman³

1997

Environ. Sci. Technol.

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“…12 In addition, individual toxaphene congeners may exhibit different toxicity. 13 Accordingly, the position and the number of the chlorine atoms on the molecule determines the magnitude and nature of biological effect. 14 Consequently, an exact assignment of the stereochemistry of the chlorine atoms on the primary carbons is necessary for correct prediction of chemical reactivity and for correct assessment of degradation or accumulation in environment.…”

Section: Introductionmentioning

confidence: 99%

“…16 have suggested that the combination of high-level ab initio optimized geometries, theoretically computed NMR chemical shifts, and experimental NMR data provides a tool that can be routinely applied for structural determinations as well as the characterization of new compounds. In this paper the gauge-including atomic orbital (GIAO) 17 method have been employed to calculate 13 C chemical shifts of the polychlorinated dihydrocamphenes 1-9 using density functional theory (DFT) at the B3LYP/6-311G* level and the HF/6-31G* optimized structures as geometry input. From the data, a linear correlation between experimental and theoretical shifts has been derived.…”

Section: Introductionmentioning

confidence: 99%

“…H and 13 C NMR spectra of 1-9 have been assigned by means of 1 H, 1 H DQF COSY (double-quantum filtered correlation spectroscopy), 1 H, 1 H ROESY (rotating frame nuclear Overhauser effect spectroscopy), PFG 1 H, 13 C HMQC (pulsed field gradient heteronuclear multiple quantum coherence), 1 H, 13 C HMBC (heteronuclear multiple bond correlation) experiments, and computer aided 1 H NMR spectral analysis. In the case of 2, the structure has been determined by X-ray methods.…”

mentioning

confidence: 99%

“…In addition, rotation barriers of compounds 7 and 9 have been characterized with the semiempirical AM1 method. The gauge-including atomic orbital (GIAO) method have been employed to calculate 13 C chemical shifts of 1-9 using density functional theory (DFT) at the B3LYP/6-311G* level and the HF/6-31G* optimized structures as geometry input. A comparison of the calculated and experimental data yielded a regression equation, which with added indicator variable (the number of chlorine atoms attached to each carbon) is capable of the accurate prediction of carbon chemical shifts for these compounds.…”

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confidence: 99%

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Syntheses, structures and spectroscopy of polychlorinated dihydrocamphenes. An experimental and theoretical study

Koivisto¹,

Kolehmainen²,

Nikiforov³

et al. 2002

Arkivoc

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Nine novel polychlorinated dihydrocamphenes (1-9) have been isolated from reaction mixtures obtained by the chlorination of lower chlorinated monoterpenes. These compounds are potential congeners of insecticide toxaphene. The H NMR spectral analysis. In the case of 2, the structure has been determined by X-ray methods. Full geometry optimizations have been performed at the ab initio HF/6-31G* level for a comparison with the conformational and structural properties obtained from the NMR-and X-ray experiments. The optimized geometries are in excellent agreement with the experimental structures. In addition, rotation barriers of compounds 7 and 9 have been characterized with the semiempirical AM1 method. The gauge-including atomic orbital (GIAO) method have been employed to calculate 13 C chemical shifts of 1-9 using density functional theory (DFT) at the B3LYP/6-311G* level and the HF/6-31G* optimized structures as geometry input. A comparison of the calculated and experimental data yielded a regression equation, which with added indicator variable (the number of chlorine atoms attached to each carbon) is capable of the accurate prediction of carbon chemical shifts for these compounds.

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Characterization of Toxaphene by High Resolution Gas Chromatography Combined with High Resolution Mass Spectrometry and Tandem Mass Spectrometry

Santos

Galcerán

Caixach

et al. 1997

Rapid Commun. Mass Spectrom.

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We examined the use of high resolution gas chromatography-electron ionization high resolution mass spectrometry (HRGC/EI-HRMS) in determining the toxaphene homologue distribution. Operating parameters such as electron energy, trap current and source temperature were optimized in order to obtain the maximum signal of the [M-C] + and [M-HCl] + • fragment ions of each homologue group. Internal interferences due to the fragment ions from the homologues with one and two additional chlorine atoms were eliminated using EI-HRMS at a resolving power of 10 000 or higher. Tandem mass spectrometry (EI-MS/MS) was used in the fragmentation studies. HRGC/EI-HRMS-selected ion monitoring (SIM) at a resolving power of 10 000 was used to determine the homologue distribution of a commercial toxaphene mixture. This technique gave detection limits of ppb level. The performance of HRGC/EI-HRMS-SIM was compared to HRGC/ECNI-MS using isobutane as a moderating gas.

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Toxaphene Insecticide: A Complex Biodegradable Mixture

Cited by 98 publications

References 4 publications

Multidimensional Gas Chromatographic Analysis of Toxaphene

Multidimensional Gas Chromatographic Analysis of Toxaphene

Syntheses, structures and spectroscopy of polychlorinated dihydrocamphenes. An experimental and theoretical study

Characterization of Toxaphene by High Resolution Gas Chromatography Combined with High Resolution Mass Spectrometry and Tandem Mass Spectrometry

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