Orchids and Bee's Knees: Investigating the Euglossine Syndrome with Gas Chromatography/Fourier Transform Infrared GC/FT-IR

1985 ◽  
Author(s):  
Gregory L. McClure ◽  
N. H. .. Williams ◽  
W. M. Whitten
Keyword(s):  
Gas Chromatography ◽  
Fourier Transform ◽  
Fourier Transform Infrared ◽  
Ft Ir

Tetrachlorodibenzo-p-Dioxin Isomer Differentiation by Capillary Gas Chromatography Fourier Transform-Infrared Spectroscopy

1987 ◽  
Vol 41 (5) ◽  
pp. 809-820 ◽  
Author(s):  
James Grainger ◽  
Leslie T. Gelbaum
Keyword(s):  
Gas Chromatography ◽  
Fourier Transform ◽  
Vapor Phase ◽  
Valence Bond ◽  
Fourier Transform Infrared ◽  
Molecular Geometry ◽  
Ether Linkage ◽  
Relative Electron ◽  
Ft Ir ◽  
Infrared Frequencies

Reference infrared vapor-phase spectra of the 22 tetrachlorodibenzo-dioxin (TCDD) isomers were recorded at low microgram concentrations. These reference spectra of synthetic mixture components separated chromatographically or by spectral subtraction exhibit distinct infrared spectra for each isomer. The infrared frequencies are delineated in correlation tables and are interpreted in terms of substitution patterns which determine the strength of the ether linkage. Absorbance values in the 1330–1280 cm−1 (C-O-C asymmetric stretch) region correlate with specific substitution patterns and molecular geometry. Relative electron-withdrawing capacities for chlorinated aromatic rings in TCDD isomers were estimated on the basis of relative capacities determined for model compounds. Qualitative correlations were established between electron-withdrawing capacities and the effects of resonance and field interactions on the ether linkage absorption frequencies of individual TCDD isomers. Gas chromatography Fourier transform infrared (GC/FT-IR) isomer assignments are generally consistent with those obtained by proton Fourier transform nuclear magnetic resonance (1H FT/NMR) and flame ionization gas chromatography (GC/FID). A chromatographically independent method of assigning TCDD isomer structures on the basis of ether linkage asymmetric stretching frequencies was established by utilization of valence-bond approximations. GC/FT-IR assignments for several TCDD isomers differ from isomer assignments in previously published results. A user-generated, vapor-phase reference library, containing individual TCDD spectra and spectra of isomer pairs that are incompletely resolved on chromatographic columns, correctly identified each isomer in variety of mixtures by means of a software algorithm.

scholarly journals Desulfurisasi Katalitik Tiofen Menggunakan Katalis CoMo/USY dalam Reaktor Batch

2018 ◽  
Vol 14 (1) ◽  
pp. 119
Author(s):  
Khoirina Dwi Nugrahaningtyas ◽  
Nanda Pratiwi ◽  
Eddy Heraldy
Keyword(s):  
Gas Chromatography ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Fourier Transform Infrared Spectroscopy ◽  
Mass Spectra ◽  
Fourier Transform Infrared ◽  
Activity Test ◽  
Ft Ir ◽  
Increasing Temperature ◽  
Desulfurization Activity

<p>Telah dilakukan uji aktivitas katalis CoMo/USY pada reaksi desulfurisasi tiofen. Reaksi dilakukan pada reaktor sistem batch dengan tekanan gas N<sub>2</sub> sebesar 1 bar gas N<sub>2</sub> dan waktu reaksi selama 1 jam. Penelitian ini bertujuan untuk mengetahui pengaruh variasi temperatur dan variasi karakter katalis pada reaksi desulfurisasi tiofen. Product desulfurisasi dianalisis dengan <em>Gas Chromatography - Mass Spectra </em>(GC-MS). Karakter kestabilan struktur katalis dilihat dengan analisis menggunakan instrumen <em>Fourier Transform Infrared Spectroscopy</em> (FT-IR). Hasil analisis terhadap uji aktivitas desulfurisasi menunjukkan bahwa pada rentang temperatur 200-300°C, rendemen bertambah dengan meningkatnya temperatur. Pada penelitian telah berhasil menghidrogenasi tiofen, tetapi belum bisa menghilangkan kandungan sulfurnya. Adapun efek karakter katalis terhadap aktivitas katalitiknya menunjukkan bahwa karakter katalis yang paling dominan adalah sifat keasaman. Katalis dengan keasaman tertinggi, yaitu katalis CoMo/USY, memiliki aktivitas tertinggi dengan rendemen produk sebesar 2,88%. Hasil analisis FT-IR terhadap katalis bekas menunjukkan bahwa struktur cukup stabil dan tidak ada pengotor yang terikat pada katalis.</p><p><strong>Catalytic Desulfurization of Thiophene </strong><strong>using</strong><strong> CoMo/USY Catalyst </strong><strong>in</strong><strong> Batch Reactor</strong>. CoMo/USY catalyst activity has been tested for thiophene desulfurization reaction. The reaction was carried out in batch system reactor with N<sub>2</sub> gas pressure of 1 bar and reaction time for 1 hour. This study aims to determine the effect of temperature variation and catalyst character variation in thiophene desulfurization reaction. The desulfurization products were analyzed by <em>Gas Chromatography - Mass Spectra </em>(GC-MS). The characters of structure catalyst were analyzed by <em>Fourier Transform Infrared Spectroscopy</em> (FT-IR). The results of the analysis of the desulfurization activity test showed that in the temperature range 200-300 °C, the yield raised with increasing temperature. The analysis results of the desulfurization activity test showed that in the temperature range of 200-300°C, the yield raised with increasing temperature. The study has successfully hydrogenated thiophene, but has not been able to eliminate the sulfur content. The effect of the catalysts character on its catalytic activity shows that the most dominant character of the catalysts was its acidity. The highest acidity catalyst, CoMo/USY catalyst, has highest activity with the product yield of 2,88%. The result of the FTIR analysis on the used catalyst show that the structure was stable and no impurities were attached the catalyst.</p>

Attenuated Total Reflection Fourier Transform Infrared (ATR FT-IR) for Rapid Determination of Microbial Cell Lipid Content: Correlation with Gas Chromatography-Mass Spectrometry (GC-MS)

2017 ◽  
Vol 71 (10) ◽  
pp. 2344-2352 ◽  
Author(s):  
Aaron Millan-Oropeza ◽  
Rolando Rebois ◽  
Michelle David ◽  
Fathi Moussa ◽  
Alexandre Dazzi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Fourier Transform ◽  
Lipid Content ◽  
Fourier Transform Infrared ◽  
Total Reflection ◽  
Attenuated Total Reflection ◽  
Transmission Mode ◽  
Gas Chromatography Mass Spectrometry ◽  
Ft Ir

There is a growing interest worldwide for the production of renewable oil without mobilizing agriculture lands; fast and reliable methods are needed to identify highly oleaginous microorganisms of potential industrial interest. The aim of this study was to demonstrate the relevance of attenuated total reflection (ATR) spectroscopy to achieve this goal. To do so, the total lipid content of lyophilized samples of five Streptomyces strains with varying lipid content was assessed with two classical quantitative but time-consuming methods, gas chromatography–mass spectrometry (GC-MS) and ATR Fourier transform infrared (ATR FT-IR) spectroscopy in transmission mode with KBr pellets and the fast ATR method, often questioned for its lack of reliability. A linear correlation between these three methods was demonstrated allowing the establishment of equations to convert ATR values expressed as CO/amide I ratio, into micrograms of lipid per milligram of biomass. The ATR method proved to be as reliable and quantitative as the classical GC-MS and FT-IR in transmission mode methods but faster and more reproducible than the latter since it involves far less manipulation for sample preparation than the two others. Attenuated total reflection could be regarded as an efficient fast screening method to identify natural or genetically modified oleaginous microorganisms by the scientific community working in the field of bio-lipids.

Comparison of Direct-Deposition Supercritical Fluid and Gas Chromatography/Fourier Transform Infrared Spectra to Condensed-Phase Library Spectra

1996 ◽  
Vol 50 (9) ◽  
pp. 1125-1133 ◽  
Author(s):  
Kelly L. Norton ◽  
Andrew M. Haefner ◽  
Hideo Makishima ◽  
George Jalsovszky ◽  
Peter R. Griffiths
Keyword(s):  
Gas Chromatography ◽  
Fourier Transform ◽  
Supercritical Fluid ◽  
Condensed Phase ◽  
Fourier Transform Infrared ◽  
Direct Deposition ◽  
Crystalline Substrate ◽  
Amorphous Substrate ◽  
Ft Ir ◽  
Crystalline Forms

Comparisons of spectra from direct-deposition (DD) capillary gas chromatography (GC) and supercritical fluid chromatography (SFC)/Fourier transform infrared (FT-IR) measurements of two quinones with C2 symmetry axes and several barbiturates to spectra from condensed-phase libraries of the corresponding compounds are reported. The best spectral search results were obtained when the eluites were deposited on an amorphous substrate, such as ZnSe. A small number of polar, hydrogen-bonding compounds were found to align with each other or with a crystalline substrate. Different crystalline forms of some polymorphic analytes can also yield ambiguous identifications. These effects produce enough differences in the DD GC/FT-IR and SFC/FT-IR spectra to cause occasional incorrect identifications when the spectra are searched against KBr-disk library spectra.

Simultaneous Orthogonal Drug Detection Using Fully Integrated Gas Chromatography with Fourier Transform Infrared Detection and Mass Spectrometric Detection

2016 ◽  
Vol 71 (5) ◽  
pp. 1050-1059 ◽  
Author(s):  
Adam Lanzarotta ◽  
Travis Falconer ◽  
Heather McCauley ◽  
Lisa Lorenz ◽  
Douglas Albright ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Fourier Transform ◽  
Synthetic Cannabinoids ◽  
Fourier Transform Infrared ◽  
Mass Spectrometric ◽  
Mass Spectrometric Detection ◽  
Infrared Detection ◽  
Ir Detector ◽  
Fully Integrated ◽  
Ft Ir

Analytes that co-elute and yield nearly identical electron ionization (EI) mass spectra, as well as analytes that yield non-specific EI fragmentation patterns, have been identified using fully integrated gas chromatography with direct deposit Fourier transform infrared detection and mass spectrometric detection (GC/FT-IR/MS). While the IR detector proved to be more selective for identifying analytes such as synthetic cannabinoids and weight loss drugs, it was limited by a relatively high detection limit of 8.4 parts per million (ppm) for non-targeted identification of sibutramine based on a single injection but was reduced to 840  parts per billion (ppb) for targeted identification of sibutramine by redepositing ten injections along the same track. The MS detector was less selective for identifying these analytes but yielded non-targeted and targeted detection limits of approximately 84 ppb and 8.4 ppb, respectively, which corresponded to a 100-fold advantage compared to the IR detector. Overall, the results of this study demonstrate that the advantages of each detector compensate for the limitations of the other, which allows a wider range of analytes and concentrations to be examined using a fully integrated GC/FT-IR/MS instrument compared to what can be examined using GC/IR or GC/MS independently. Not only does this approach reduce consumption of laboratory resources and time, it provides IR and MS information on the same sample, which is important for forensic analyses that require data from two or more orthogonal techniques to make an identification.

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