HRGC Separations of 160 Chlorobiphenyls in Technical Mixtures on Four Polar Narrow-Bore Columns

B⊘wadt, S.; Skej⊘-andresen, H.; Montanarella, Luca; Larsen, B.

doi:10.1080/03067319408039798

Cited by 24 publications

(7 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The representation of the calculated k for all the PCBs investigated with the total number and position of the chlorine atoms (number of chlorine atoms in the ortho position) (Figure ) shows that the retention mechanism of the PCBs in this stationary phase is similar to that observed with active charcoal (Amoco-PX21) 4 and very close to those observed with activated Florisil . Retention on the PYE stationary phase is highly influenced by solute planarity, and this phase has been shown to be excellent for isolating both coplanar non-ortho and mono-ortho PCBs from the bulk of PCBs in technical mixtures. − Retention increased with the planarity of the molecule and with degree of chlorination. However, some important differences in retention have been observed, depending on the distribution pattern of chlorine atoms on the biphenyl ring, due to the fact that PCBs with similar molecule structure but with different π electron densities are separated.…”

Section: Resultsmentioning

confidence: 60%

“…A large number of stationary phases in high-resolution gas chromatography (HRGC), including long-chain alkyl polysiloxanes phases, − liquid crystalline phases, , and cyanopropyl , and diphenyl groups in methyl polysiloxane copolymers, ,− have been studied for separation of complex mixtures of PCBs. Larsen's critical review in 1995 of the state of the art of HRGC separation of PCB congeners concluded that none of the 11 stationary phases commercially available, and for which there are published chromatograms and retention data for at least all PCB congeners occurring in significant concentrations in technical mixtures, ,,,, were able to resolve all 209 congeners. Nor were they able to resolve the estimated 150 congeners present in technical mixtures, or the 36 priority congeners identified by McFarland and Clarke, and most surprisingly, they were not even able to resolve the set of seven indicator congeners.…”

mentioning

confidence: 99%

See 1 more Smart Citation

Simultaneous Separation of Coplanar and Chiral Polychlorinated Biphenyls by Off-Line Pyrenyl-Silica Liquid Chromatography and Gas Chromatography. Enantiomeric Ratios of Chiral Congeners

Ramos¹,

Hernández²,

González³

1998

Anal. Chem.

View full text Add to dashboard Cite

A method for the unambiguous determination of 41 key polychlorinated biphenyls (PCBs) (including coplanar and chiral congeners) and the enantiomeric ratio of chiral congeners is described. The method includes a fractionation step using a 2-(1-pyrenyl) ethyldimethylsilylated silica column for separating the polychlorinated biphenyls according to the number of chlorine atoms in the ortho positions. High-resolution gas chromatography with an electron capture detector and an achiral column was used to determine the PCB congener content in each fraction. The enantiomeric ratio of chiral congeners was calculated by high-resolution gas chromatography with a mass spectrometry detector using a chiral column. The method was found to be inexpensive, rapid, effective, and reliable under the operational conditions proposed. It eliminates the main coelution problems among the polychlorinated biphenyl congeners. It also makes it possible to determine the enantiomeric ratio of nine chiral congeners using monodimensional gas chromatography. The method was applied successfully to the analysis of the coplanar and atropisomeric polychlorinated biphenyl congeners in dolphin liver samples. The enantiomeric ratio of nine chiral congeners is also reported for the first time.

show abstract

Section: Resultsmentioning

confidence: 60%

mentioning

confidence: 99%

Simultaneous Separation of Coplanar and Chiral Polychlorinated Biphenyls by Off-Line Pyrenyl-Silica Liquid Chromatography and Gas Chromatography. Enantiomeric Ratios of Chiral Congeners

Ramos¹,

Hernández²,

González³

1998

Anal. Chem.

View full text Add to dashboard Cite

show abstract

“…The extracts of the reference material were additionally analyzed on a second gas chromatograph (HP 5890 Series II with on-column injector), where a column of different polarity (DB5, 50 m × 0.32 mm i.d. ; film thickness 0.25 μm; J & W, Folsom CA) was installed in order to achieve coelution-free performance of each analyte. − Use of two columns of different polarity provides a higher analytical correctness. Therefore, the prescription for the participants of the intercomparison study included the analyses of extracts with two chromatographic columns.…”

Section: Methodsmentioning

confidence: 99%

Determination of Chlorinated Hydrocarbons in Marine Sediments at the Part-per-Trillion Level with Supercritical Fluid Extraction

Sterzenbach¹,

Wenclawiak²,

Weigelt³

1997

Anal. Chem.

View full text Add to dashboard Cite

An off-line supercritical fluid extraction method has been developed for the determination of polychlorinated biphenyls and organochlorine pesticides at the part-per-trillion level in marine sediments. Four different extraction conditions were evaluated: pure carbon dioxide at 60 °C/220 atm and 100 °C/350 atm; addition of methanol prior to the static extraction at 80 °C/350 atm; addition of methanol prior to the static extraction step and continuously during the dynamic extraction step at 80 °C/350 atm. Only the latter condition gave extraction recoveries that were comparable and for some compounds higher than Soxhlet recoveries. The significance of differences between the two extraction methodes was determined in an F- and t-test. The method was validated by analysis of a reference material from an international intercomparison exercise.

show abstract

“…The retention time of PCB congeners has also been previously investigated and reported [21][22][23][24]. Due to the need to control the PCBs level in the environment, one of the most commonly used methods for their analysis in environmental samples is gas chromatography coupled with an electron-capture detector, because of its high sensitivity toward halogenated compounds [25,26], but easy identification of individual congeners remains unresolved for the moment [27,28]. Retention in chromatography is the result of a competitive distribution process of the solute between mobile and stationary phases, in which the partitioning of the solute between these phases is largely determined by the molecular structure.…”

Section: Introductionmentioning

confidence: 99%

Computational Model for Chromatographic Relative Retention Time of Polychlorinated Biphenyls Using Sub-structural Molecular Fragments

Saaidpour

2016

CMST

View full text Add to dashboard Cite

Quantitative structure-retention relationship (QSRR) analysis is a useful technique capable of relating chromatographic retention time to the chemical structure of a solute. Using the sub-structural molecular fragments (SMF) derived directly from the molecular structures, the gas chromatographic relative retention times (RRTs) of 209 polychlorinated biphenyls (PCBs) on the SE-54 stationary phase were calculated. An eight-variable regression equation with the correlation coefficient of 0.9945 and the root mean square errors of 0.0134 was developed. Forward and backward stepwise regression variable selection and multi-linear regression analysis (MLRA) are combined to describe the effect of molecular structure on the RRT of PCB according to the QSRR method. To quantitatively relate RRT with the molecular structure MLR analysis is performed on the set of 163 sub-structural molecular fragments (SMF) provided by the ISIDA software. The eight fragments selected by variable subset selection, all belonging to the sub-fragments, adequately represent the structural factors influencing the affinity of PCB to SE-54 stationary phase in the separation process. Finally, a QSRR model is selected based on leave-one-out cross-validation and its prediction ability is further tested on 42 representative compounds excluded from model calibration. The prediction results from the MLR model are in good agreement with the experimental values. By applying the MLR method we can predict the test set with squared cross validated correlation coefficient (Q 2 ext ) of 0.9913 and root mean square error (RMSE) of 0.0169.

show abstract

HRGC Separations of 160 Chlorobiphenyls in Technical Mixtures on Four Polar Narrow-Bore Columns

Cited by 24 publications

References 17 publications

Simultaneous Separation of Coplanar and Chiral Polychlorinated Biphenyls by Off-Line Pyrenyl-Silica Liquid Chromatography and Gas Chromatography. Enantiomeric Ratios of Chiral Congeners

Simultaneous Separation of Coplanar and Chiral Polychlorinated Biphenyls by Off-Line Pyrenyl-Silica Liquid Chromatography and Gas Chromatography. Enantiomeric Ratios of Chiral Congeners

Determination of Chlorinated Hydrocarbons in Marine Sediments at the Part-per-Trillion Level with Supercritical Fluid Extraction

Computational Model for Chromatographic Relative Retention Time of Polychlorinated Biphenyls Using Sub-structural Molecular Fragments

Contact Info

Product

Resources

About