Gas chromatographic separation of atropisomeric alkylated and polychlorinated biphenyls using modified cyclodextrins

König, Wilfried Α.; Gehrcke, Bärbel; Runge, Torsten M.; Wolf, Christian

doi:10.1002/jhrc.1240160609

Cited by 74 publications

(23 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This was shown by Krnig et al (1993), who carried out isothermal GC using capillary columns coated with modified cyclodextrins, allowing separation of enantiomeric structures, and determined the separation of the two atropisomers of 2,2 '-diisopropylbiphenyl as a function of column temperature.…”

Section: Atropisomersmentioning

confidence: 97%

Diagenetic and catagenetic products of isorenieratene: Molecular indicators for photic zone anoxia

Koopmans

Köster

Kaam-Peters

et al. 1996

Geochimica et Cosmochimica Acta

367

152

View full text Add to dashboard Cite

Abstract--A wide range of novel diagenetic and catagenetic products of the diaromatic carotenoid isorenieratene, a pigment of the photosynthetic green sulphur bacteria Chlorobiaceae, has been identified in a number of sedimentary rocks ranging from Ordovician to Miocene. Compound identification is based on NMR, mass spectrometry, the presence of atropisomers, and stable carbon isotopes. Atropisomers contain an axially chiral centre which, in combination with other chiral centres, results in two or more diastereomers that can be separated on a normal GC column. Chlorobiaceae use the reverse TCA cycle to fix carbon, so that their biomass is enriched in 13C. High ~3C contents of isorenieratene derivatives therefore support their inferred origins.Isorenieratene derivatives include C4o, C33, and C32, diaryl isoprenoids and short-chain aryl isoprenoids with additional aromatic and/or S-containing rings. C33 and C32 compounds are diagenetic products of C33 and C32 "carotenoids" formed from isorenieratene during early diagenesis through expulsion of toluene and m-xylene, respectively. Cyclisation of the polyene acyclic isoprenoid chain can proceed via an intramolecular Diels-Alder reaction, followed by aromatisation of the newly formed ring. Sulphurisation is also an important process during early diagenesis, competing with expulsion and cyclisation. Sulphur-bound isorenieratane is released during progressive diagenesis, due to cleavage of relatively weak S-S and C-S bonds. Cleavage of C-C bonds during aromatisation of newly formed rings and during catagenesis yields short-chain compounds. The inherent presence of a conjugated double bond system in carotenoids implies that similar diagenetic and catagenetic reactions can occur with all carotenoids.Chlorobiaceae live at or below the oxic/anoxic boundary layer and require both light and H2S. The presence of isorenieratene or its diagenetic and catagenetic products in ancient sedimentary rocks and crude oils is therefore an excellent indication for photic zone anoxia in the depositional environment. Diagenetic and catagenetic products of isorenieratene are expected to find applications in reconstruction of palaeoenvironments and in oil-oil and oil-source rock correlation studies. Their presence in several petroleum source rocks suggests that anoxia is an important environmental parameter for the preservation of organic matter.

show abstract

Section: Atropisomersmentioning

confidence: 97%

Diagenetic and catagenetic products of isorenieratene: Molecular indicators for photic zone anoxia

Koopmans

Köster

Kaam-Peters

et al. 1996

Geochimica et Cosmochimica Acta

367

152

View full text Add to dashboard Cite

show abstract

“…However, only in few occasions chiral PCBs were separated. Separation of chiral PCBs are currently performed by capillary gas chromatography (GC) [3,[11][12][13][14].…”

Section: Introductionmentioning

confidence: 99%

“…König et al [13] resolved PCBs 45, 95 and 139 on a GC column coated with octakis(2,6-di-Omethyl-3-O-pentyl)-g-cyclodextrin. Magnusson et al [14] reported simultaneous GC enantioseparation of a mixture of nine chiral PCBs using a binary chiral selector containing permethylated-b-CD and heptakis (2,3-…”

Section: Introductionmentioning

confidence: 99%

Chiral separation of polychlorinated biphenyls using a combination of hydroxypropyl-γ-cyclodextrin and a polymeric chiral surfactant

Edwards

Shamsi

2002

Electrophoresis

View full text Add to dashboard Cite

Chiral separation of moderately to highly hydrophobic polychlorinated biphenyls (PCBs) using a conventional chiral micelle or a polymeric chiral surfactant, as the single chiral selector is very difficult since the hydrophobic interactions between the chiral PCB and the monomeric or polymeric surfactant is very strong. Combined use of a polymeric chiral surfactant, polysodium N-undecanoyl-D-valinate (poly-D-SUV) with hydroxypropyl-gamma-cyclodextrin (HP-gamma-CD) was successful in cyclodextrin modified electrokinetic chromatography (CD-EKC) enantioseparation of PCB congeners. Addition of HP-gamma-CD to the background electrolyte containing poly-D-SUV functioned to improved chiral resolution for the PCBs and reduce the analysis time for these congeners. In addition, concentration of methanol, concentration of 2-(N-cyclohexylamino) ethanesulfonic acid (CHES) buffer and separation voltage was also varied to optimize multicomponent separation of five chiral PCBs. Simultaneous separation and enantioseparation of all five PCBs was possible in less than 50 min under optimized conditions that requires a 5 mM CHES solution buffered at about pH 10 with 1.5% w/v (ca. 60 mM) poly-D-SUV and 16 mM HP-gamma-CD. In addition, 1 M urea and 20% v/v methanol should be added as organic modifier and the capillary temperature maintained at 45 degrees C. As expected the polymeric surfactant showed improved chiral resolution of PCBs over conventional micelles of SUV. Under optimized conditions, when CD-EKC of chiral PCBs using poly-D-SUV was compared to sodium dodecyl sulfate (SDS), better resolution, higher efficiency and shorter analysis time was achieved with poly-D-SUV.

show abstract

“…Derivados de β-ciclodextrinas (β-CD) são utilizados como fases estacionárias quirais em CGAR. O uso dessas fases resultou na resolução enantiomérica de precursores quirais e intermediários sintéticos de compostos com atividade biológica, enantioseletividade simultânea de componentes quirais de aromas com diferentes grupos funcionais, etc [95][96][97][98] . Vários derivados de ciclodextrinas, descritos na literatura e usados como fases estacionárias quirais, são misturas complexas.…”

Section: Oligossacarídeosunclassified

Estado da arte da cromatografia gasosa de alta resolução e alta temperatura

Pereira

Neto

2000

Quím. Nova

View full text Add to dashboard Cite

Gas chromatographic separation of atropisomeric alkylated and polychlorinated biphenyls using modified cyclodextrins

Cited by 74 publications

References 16 publications

Diagenetic and catagenetic products of isorenieratene: Molecular indicators for photic zone anoxia

Diagenetic and catagenetic products of isorenieratene: Molecular indicators for photic zone anoxia

Chiral separation of polychlorinated biphenyls using a combination of hydroxypropyl-γ-cyclodextrin and a polymeric chiral surfactant

Estado da arte da cromatografia gasosa de alta resolução e alta temperatura

Contact Info

Product

Resources

About