GC-MS fragmentation patterns of sprayed endosulfan and its sulphate metabolite in samples of Theobroma cacao L from a field kinetic study

Edebi N. Vaikosen, Lorraine T. Gibson, Christine M. Davidson, Bamidele I. Owolabi, Kayode Adebowale, Benjamin U. Ebeshi, Paul N.E. Diagboya

Research output: Contribution to journalArticle

Abstract

Most environmental analytical methods for the determination of organochlorine pesticides (OCPs) are multi-residual with other organic compounds co-extracted and co-eluted. This has been observed in GC spectra using classical detectors like electron-capture detector (ECD) even after appropriate clean-up. This limitation could be resolved by using GC-MS methods which are more specific and selective. Thus, a commercial-grade endosulfan treated Theobroma cacao plantation was sampled. Representative samples comprising leaves, stem bark and pulp were obtained between 0.5 h and 60 d after treatment. Samples were analyzed for residual parent endosulfan (α- and β-isomers) as well as the metabolite endosulfan sulphate using an ion trap GC-MS. The retention times and chromatogram peaks obtained for various endosulfan were identified and compared with reference standards, and confirmed with National Institute of Standards and Technology (NIST) library. Results showed that the molecular ion at m/z 407 was exhibited by α- and β- endosulfan, representing the parent molecular ion M+• ([C9H6Cl6SO3]+•). The α-isomer was more thermally stable, hence exhibited more relative abundance. Other predominant peaks were 339, 307, 277, 265, 243, 241, 207, 195, 160, 159, 99 and 75 m/z. The peak at m/z 159 was the base molecular ion. For endosulfan sulphate, the peak at m/z 422 corresponded to parent molecular ion (M+•), while m/z 424 was due to isotopic pattern characteristic of the chlorine atom. The peaks at 387, 357, 289, 272, 229, 206, 170, and 120 m/z were characteristic for the sulphate metabolite. The m/z peak at 272 was the base molecular ion, while m/z 143 may be due to metabolite diol and lactone. These results showed that the various endosulfan species can be identified and confirmed simultaneously using a GC-MS.
LanguageEnglish
Number of pages26
JournalEuropean Journal of Mass Spectrometry
Publication statusAccepted/In press - 15 Nov 2018

Fingerprint

Endosulfan
Metabolites
Ions
Kinetics
Isomers
Detectors
Chlorine
Lactones
Organic compounds
Pesticides
Sulfates
Pulp
endosulfan sulfate
Atoms
Electrons

Keywords

  • parent isomers
  • lactone
  • co-elution
  • carbene carbocation
  • dichlorobenzene
  • theobroma cacao

Cite this

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title = "GC-MS fragmentation patterns of sprayed endosulfan and its sulphate metabolite in samples of Theobroma cacao L from a field kinetic study",
abstract = "Most environmental analytical methods for the determination of organochlorine pesticides (OCPs) are multi-residual with other organic compounds co-extracted and co-eluted. This has been observed in GC spectra using classical detectors like electron-capture detector (ECD) even after appropriate clean-up. This limitation could be resolved by using GC-MS methods which are more specific and selective. Thus, a commercial-grade endosulfan treated Theobroma cacao plantation was sampled. Representative samples comprising leaves, stem bark and pulp were obtained between 0.5 h and 60 d after treatment. Samples were analyzed for residual parent endosulfan (α- and β-isomers) as well as the metabolite endosulfan sulphate using an ion trap GC-MS. The retention times and chromatogram peaks obtained for various endosulfan were identified and compared with reference standards, and confirmed with National Institute of Standards and Technology (NIST) library. Results showed that the molecular ion at m/z 407 was exhibited by α- and β- endosulfan, representing the parent molecular ion M+• ([C9H6Cl6SO3]+•). The α-isomer was more thermally stable, hence exhibited more relative abundance. Other predominant peaks were 339, 307, 277, 265, 243, 241, 207, 195, 160, 159, 99 and 75 m/z. The peak at m/z 159 was the base molecular ion. For endosulfan sulphate, the peak at m/z 422 corresponded to parent molecular ion (M+•), while m/z 424 was due to isotopic pattern characteristic of the chlorine atom. The peaks at 387, 357, 289, 272, 229, 206, 170, and 120 m/z were characteristic for the sulphate metabolite. The m/z peak at 272 was the base molecular ion, while m/z 143 may be due to metabolite diol and lactone. These results showed that the various endosulfan species can be identified and confirmed simultaneously using a GC-MS.",
keywords = "parent isomers, lactone, co-elution, carbene carbocation, dichlorobenzene, theobroma cacao",
author = "Vaikosen, {Edebi N.} and Gibson, {Lorraine T.} and Davidson, {Christine M.} and Owolabi, {Bamidele I.} and Kayode Adebowale and Ebeshi, {Benjamin U.} and Diagboya, {Paul N.E.}",
year = "2018",
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GC-MS fragmentation patterns of sprayed endosulfan and its sulphate metabolite in samples of Theobroma cacao L from a field kinetic study. / Vaikosen, Edebi N.; Gibson, Lorraine T.; Davidson, Christine M.; Owolabi, Bamidele I.; Adebowale, Kayode; Ebeshi, Benjamin U.; Diagboya, Paul N.E.

In: European Journal of Mass Spectrometry, 15.11.2018.

Research output: Contribution to journalArticle

TY - JOUR

T1 - GC-MS fragmentation patterns of sprayed endosulfan and its sulphate metabolite in samples of Theobroma cacao L from a field kinetic study

AU - Vaikosen, Edebi N.

AU - Gibson, Lorraine T.

AU - Davidson, Christine M.

AU - Owolabi, Bamidele I.

AU - Adebowale, Kayode

AU - Ebeshi, Benjamin U.

AU - Diagboya, Paul N.E.

PY - 2018/11/15

Y1 - 2018/11/15

N2 - Most environmental analytical methods for the determination of organochlorine pesticides (OCPs) are multi-residual with other organic compounds co-extracted and co-eluted. This has been observed in GC spectra using classical detectors like electron-capture detector (ECD) even after appropriate clean-up. This limitation could be resolved by using GC-MS methods which are more specific and selective. Thus, a commercial-grade endosulfan treated Theobroma cacao plantation was sampled. Representative samples comprising leaves, stem bark and pulp were obtained between 0.5 h and 60 d after treatment. Samples were analyzed for residual parent endosulfan (α- and β-isomers) as well as the metabolite endosulfan sulphate using an ion trap GC-MS. The retention times and chromatogram peaks obtained for various endosulfan were identified and compared with reference standards, and confirmed with National Institute of Standards and Technology (NIST) library. Results showed that the molecular ion at m/z 407 was exhibited by α- and β- endosulfan, representing the parent molecular ion M+• ([C9H6Cl6SO3]+•). The α-isomer was more thermally stable, hence exhibited more relative abundance. Other predominant peaks were 339, 307, 277, 265, 243, 241, 207, 195, 160, 159, 99 and 75 m/z. The peak at m/z 159 was the base molecular ion. For endosulfan sulphate, the peak at m/z 422 corresponded to parent molecular ion (M+•), while m/z 424 was due to isotopic pattern characteristic of the chlorine atom. The peaks at 387, 357, 289, 272, 229, 206, 170, and 120 m/z were characteristic for the sulphate metabolite. The m/z peak at 272 was the base molecular ion, while m/z 143 may be due to metabolite diol and lactone. These results showed that the various endosulfan species can be identified and confirmed simultaneously using a GC-MS.

AB - Most environmental analytical methods for the determination of organochlorine pesticides (OCPs) are multi-residual with other organic compounds co-extracted and co-eluted. This has been observed in GC spectra using classical detectors like electron-capture detector (ECD) even after appropriate clean-up. This limitation could be resolved by using GC-MS methods which are more specific and selective. Thus, a commercial-grade endosulfan treated Theobroma cacao plantation was sampled. Representative samples comprising leaves, stem bark and pulp were obtained between 0.5 h and 60 d after treatment. Samples were analyzed for residual parent endosulfan (α- and β-isomers) as well as the metabolite endosulfan sulphate using an ion trap GC-MS. The retention times and chromatogram peaks obtained for various endosulfan were identified and compared with reference standards, and confirmed with National Institute of Standards and Technology (NIST) library. Results showed that the molecular ion at m/z 407 was exhibited by α- and β- endosulfan, representing the parent molecular ion M+• ([C9H6Cl6SO3]+•). The α-isomer was more thermally stable, hence exhibited more relative abundance. Other predominant peaks were 339, 307, 277, 265, 243, 241, 207, 195, 160, 159, 99 and 75 m/z. The peak at m/z 159 was the base molecular ion. For endosulfan sulphate, the peak at m/z 422 corresponded to parent molecular ion (M+•), while m/z 424 was due to isotopic pattern characteristic of the chlorine atom. The peaks at 387, 357, 289, 272, 229, 206, 170, and 120 m/z were characteristic for the sulphate metabolite. The m/z peak at 272 was the base molecular ion, while m/z 143 may be due to metabolite diol and lactone. These results showed that the various endosulfan species can be identified and confirmed simultaneously using a GC-MS.

KW - parent isomers

KW - lactone

KW - co-elution

KW - carbene carbocation

KW - dichlorobenzene

KW - theobroma cacao

UR - https://journals.sagepub.com/loi/ems

M3 - Article

JO - European Journal of Mass Spectrometry

T2 - European Journal of Mass Spectrometry

JF - European Journal of Mass Spectrometry

SN - 1469-0667

ER -