Gas Chromatographic/Matrix Isolation/Fourier Transform Infrared Spectra of the Laterally Chlorinated Dibenzo-p-Dioxins and Dibenzofurans

1989 ◽  
Vol 43 (8) ◽  
pp. 1317-1324 ◽  
Author(s):  
Charles J. Wurrey ◽  
Billy J. Fairless ◽  
Harry E. Kimball

Reference-quality gas chromatographic/matrix isolation/Fourier transform infrared spectra have been recorded for the following fifteen compounds, which collectively are referred to as the “laterally” chlorinated dibenzo- p-dioxins and dibenzofurans: 2,3,7,8-tetrachlorodibenzo- p-dioxin (2,3,7,8-TCDD); 1,2,3,7,8-pentachlorodibenzo- p-dioxin (1,2,3,7,8-PeCDD);l,2,3,4,7,8-hexachlorodibenzo- p-dioxin(1,2,3,4,7,8-HxCDD)>; 1,2,3,6,7,8,-hexachlorodibenzo- p-dioxin(1,2,3,6,7,8-HxCDD); 1,2,3,7,8,9-hexachlorodibenzo- p-dioxin (1,2,3,7,8,9-HxCDD); 1,2,3,4,6,7,8-heptachlorodibenzo- p-dioxin (1,2,3,4,6,7,8-HpCDD); 2,3,7,8-tetrachlorodibenzofuran (2,3,7,8-TCDF); 1,2,3,7,8-pentachlorodibenzofuran (1,2,3,7,8-PeCDF); 2,3,4,7,8-pentachlorodibenzofuran (2,3,4,7,8-PeCDF); 1,2,3,4,7,8-hexachlorodibenzofuran(1,2,3,4,7,8-HxCDF); 1,2,3,6,7,8-hexachlorodibenzofuran (1,2,3,6,7,8-HxCDF); 1,2,3,7,8,9-hexachlorodibenzofuran (1,2,3,7,8,9-HxCDF); 2,3,4,6,7,8-hexachlorodibenzofuran (2,3,4,6,7,8-HxCDF); 1,2,3,4,6,7,8-heptachlorodibenzofnran (1,2,3,4,6,7,8-HpCDF); and 1,2,3,4,7,8,9-heptachlorodibenzofuran (1,2,3,4,7,8,9-HpCDF). These spectra are discussed qualitatively and, for the laterally chlorinated dioxins, are compared to previously recorded gas-phase GC/FT-IR spectra. Estimates of the instrumental detection limits for these compounds, using matrix isolation GC/FT-IR spectroscopy, were found to fall in the mid-to-high picogram and low nanogram ranges.

1989 ◽  
Vol 43 (6) ◽  
pp. 998-1003 ◽  
Author(s):  
W. M. Coleman ◽  
Bert M. Gordon

A set of five search routines—absolute difference, absolute derivative, square difference, square derivative, and Euclidean difference—have been applied to the analysis of the matrix isolation/Fourier transform-infrared spectra (MI/FT-IR) of the components of four essential oils: coriander oil, lemon oil, geranium oil, and citronella oil. The routines were tested under a variety of parameters on a diverse set of compounds and IR spectra. Areas of acceptable performance by the routines as well as areas of marginal performance are discussed. Under the conditions of this study, the absolute derivative routine is judged to be the most acceptable of the five.


1989 ◽  
Vol 43 (6) ◽  
pp. 1004-1008 ◽  
Author(s):  
W. M. Coleman ◽  
Bert M. Gordon

Matrix isolation Fourier transform infrared spectra (MI/FT-IR) of a series of essential oil components have been described. Clear, well-defined differences were detected in the MI/FT-IR spectra of compounds having minor differences in their structure. A library search routine was found to correctly identify components of interest when visual differences were not clearly evident. The presence of discrete conformers in the argon matrix resulted in the presence of split absorptions in the carbonyl band for selected compounds.


1988 ◽  
Vol 42 (2) ◽  
pp. 304-309 ◽  
Author(s):  
W. M. Coleman ◽  
Bert M. Gordon

Matrix isolation Fourier transform infrared (MI/FT-IR) data has been presented that documents the presence of discrete conformers in an argon matrix for a series of ketones. The distribution of conformers in the matrix was related to the structure of the molecule, in that rigid structures (i.e., small rings, bicyclic systems, and unsaturated systems) displayed simple carbonyl absorption patterns relative to those of their less rigid counterparts. Also, conformer isolation was seen for halosubstituted ketones. These results are in agreement with previous findings concerning the vapor-phase (VP) spectra of these molecules.


1989 ◽  
Vol 43 (2) ◽  
pp. 298-304 ◽  
Author(s):  
W. M. Coleman ◽  
Bert M. Gordon ◽  
Brian M. Lawrence

Matrix isolation Fourier transform infrared spectra (MI/FT-IR), mass spectra (MS), carbon-13 Nuclear Magnetic Resonance (13C-NMR) spectra, condensed-phase infrared spectra, and vapor-phase infrared (IR) spectra are presented for a series of terpene compounds. Subtle differences in positional and configurational isomers commonly found with terpenes could be easily detected by the MI/FT-IR spectra. The results are comparable in some aspects to those obtainable from 13C-NMR and thin-film IR; however, most importantly, they are acquired at the low nanogram level for MI/FT-IR, as compared to the milligram level for the other techniques. These results represent an advance in the technology available for the analysis of complex mixtures such as essential oils containing terpene-like molecules.


1987 ◽  
Vol 41 (7) ◽  
pp. 1163-1169 ◽  
Author(s):  
W. M. Coleman ◽  
Bert M. Gordon

Matrix-isolated (MI) Fourier transform infrared spectra (FT-IR) have been collected on a series of esters and ketones. The values for the carbonyl absorption are intermediate between the values for vapor-phase (VP) and solid-state (SS) phases. The spectra reveal a splitting or broadening of the carbonyl absorption in the majority of cases for both compound types. The splitting, on the order of 5 to 10 cm−1, does not appear to be a function of concentration at ≤20 ng on the cryogenic disk. The splitting is also not unequivocally due to steric hindrance about the carbonyl group. Compounds with liner as well as branched substituents display spectra having split carbonyl absorptions. Isolation of molecules within multiple types of matrix sites is advanced as the predominant cause of the splitting phenomenon. Implications and consequences of the observed splitting are discussed.


1987 ◽  
Vol 41 (7) ◽  
pp. 1169-1172 ◽  
Author(s):  
W. M. Coleman ◽  
Bert M. Gordon

Matrix-isolated (MI) Fourier transform infrared spectra (FT-IR) have been collected on a series of aldehydes and acids. The values for the carbonyl absorption are intermediate between the higher values for vapor-phase (VP) and lower values for solid-state (SS) phases. Substituent effects on aromatic rings induce shifts in carbonyl absorptions in the same manner as found in VP and SS studies. The magnitude of the shifts is approximately the same for all three phases. The spectra reveal a splitting or broadening of the carbonyl absorption for both aldehydes and acids. The size of the molecule affects the degree of band broadening. In certain cases discrete conformers appear to have been isolated in the matrix.


2020 ◽  
Vol 35 (3) ◽  
pp. 203-215
Author(s):  
Mehmet Emin Diken ◽  
Berna Koçer Kizilduman ◽  
Begümhan Yilmaz Kardaş ◽  
Enes Emre Doğan ◽  
Mehmet Doğan ◽  
...  

The nanocomposite hydrogels were prepared by dispersing of the nanopomegranate seed particles into poly(vinyl alcohol)/poly(acrylic acid) blend matrix in an aqueous medium by the solvent casting method. These hydrogels were characterized using scanning electron microscopy, Fourier transform infrared spectra, differential scanning calorimetry, and optical contact angle instruments. The nanopomegranate seed, blend, and hydrogel nanocomposites were tested for microbial activity. In addition, cytocompatibilities of these blend and hydrogel nanocomposites/composites were tested on human lymphocyte with in vitro MTS cell viability assays. Fourier transform infrared spectra revealed that esterification reaction took place among functional groups in the structure of poly(vinyl alcohol) and poly(acrylic acid). The hydrophilic properties of all hydrogels decreased with increasing nanopomegranate seed content. The mean diameters of the nanopomegranate seed particles were about 88 nm. Nanopomegranate seed particles demonstrated antibacterial properties against gram-positive bacteria, Staphylococcus aureus, and gram-negative bacteria, Escherichia coli. The lymphocyte viabilities increased after addition of nanopomegranate seeds into the polymer blend. The swelling behavior of blend and hydrogels was dependent on the cross-linking density created by the reaction between poly(vinyl alcohol)/poly(acrylic acid) blend and nanopomegranate seed. Scanning electron microscopy images were highly consistent with Fourier transform infrared spectra, differential scanning calorimetry, and antibacterial activity results.


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