CHROMATOGRAPHIC AND MICROSCOPIC DETECTION OF GLUCOSINOLATES IN RAPESEED USING N,2,6-TRICHLORO-p- BENZOQUINONEIMINE

1984 ◽  
Vol 64 (4) ◽  
pp. 869-878 ◽  
Author(s):  
S. H. YIU ◽  
F. W. COLLINS ◽  
R. G. FULCHER ◽  
I. ALTOSAAR
Keyword(s):  
Gas Chromatography ◽  
Room Temperature ◽  
Brassica Campestris ◽  
Protein Bodies ◽  
Distilled Water ◽  
Two Dimensional ◽  
Brassica Napus L ◽  
Methanolic Extracts ◽  
Microscopic Studies

A new histochemical method for detecting glucosinolates in rapeseed (Brassica napus L. ’Midas’) methanolic extracts and rapeseed (Brassica campestris L. ’Candle’) hand-cut sections has been developed using N,2,6-trichloro-p-benzoquinoneimine (TCQ) as the staining reagent. The specificity of TCQ was established by the following experiments. (1) TCQ was used as a spray reagent for detecting thio sugars separated from (a) crude and (b) partially purified rapeseed extracts on silica gel coated chromatograms. By comparison, the reaction of TCQ was relatively more selective than that of alkaline silver nitrate as it detected fewer spots on the chromatogram. (2) Rapeseed extracts and glucosinolate (GS) standards were analyzed on the same plate by one- and two-dimensional chromatography. After spraying with TCQ two of the three spots originated from the extract had the same color (yellow) reaction and similar Rf values as those of 3-butenyl GS and 2-hydroxy-3-butenyl GS. (3) Gas chromatography was used to identify the TCQ-reactive compounds present in the rapeseed extract. 3-butenyl GS and 2-hydroxy-3-butenyl GS were present as major constituents while 4-pentenyl GS, 2-hydroxy-4-pentenyl GS and an hydroxyindolylmethyl GS formed the minor entity. The use of TCQ for detecting glucosinolates in situ was established by the following microscopic studies. Hand-cut sections were prepared, stained with TCQ and examined microscopically. Protein bodies found inside cells of the cotyledon were the only stained (yellow in color) structures. The number of yellow-colored protein bodies decreased if the sections were left untreated at room temperature for more than 10 min prior to staining. Treatment of the sections with distilled water, 70% methanol or myrosinase before staining diminished the stainability of the protein bodies.Key words: Rapeseed structure, glucosinolates, chromatographic analyses, N,2,6-trichloro-p-benzoquinoneimine

scholarly journals Thin, Flexible Supercapacitors Made from Carbon Nanofiber Electrodes Decorated at Room Temperature with Manganese Oxide Nanosheets

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
S. K. Nataraj ◽  
Q. Song ◽  
S. A. Al-Muhtaseb ◽  
S. E. Dutton ◽  
Q. Zhang ◽  
...  
Keyword(s):  
Thin Film ◽  
Electrochemical Performance ◽  
Specific Capacitance ◽  
Carbon Nanofibers ◽  
Room Temperature ◽  
Composite Electrode ◽  
Carbon Nanofiber ◽  
Two Dimensional ◽  
Nanostructured Composite

We report the fabrication and electrochemical performance of a flexible thin film supercapacitor with a novel nanostructured composite electrode. The electrode was prepared byin situcoprecipitation of two-dimensional (2D) MnO2nanosheets at room temperature in the presence of carbon nanofibers (CNFs). The highest specific capacitance of 142 F/g was achieved for CNFs-MnO2electrodes in sandwiched assembly with PVA-H4SiW12O40·nH2O polyelectrolyte separator.

scholarly journals FLORAL EXTRACTS OF ALLAMANDA BLANCHETII AND ALLAMANDA CATHARTICA ARE COMPARATIVELY HIGHER RESOURCE OF ANTI-OXIDANTS AND POLYSACCHARIDES THAN LEAF AND STEM EXTRACTS

2018 ◽  
Vol 10 (4) ◽  
pp. 36 ◽  
Author(s):  
Chandreyi Ghosh ◽  
Sayantan Banerjee
Keyword(s):  
Secondary Metabolites ◽  
Aqueous Extract ◽  
Room Temperature ◽  
Ornamental Plants ◽  
Distilled Water ◽  
Aqueous Extracts ◽  
Organic Extract ◽  
Standard Methods ◽  
Methanolic Extracts ◽  
Anti Oxidant

Objective: The present study undertakes a comparative analysis of the level of secondary metabolites present in the leaf, flower and stem of the two ornamental plants, Allamanda blanchetii and Allamanda cathartica.Methods: The two plant species, Allamanda blanchetii and Allamanda cathartica were collected, washed, shade dried in room temperature and powered in mechanical grinder. Phytochemicals were extracted from the power with methanol and double distilled water. The estimation of flavonoids, polyphenols, polysaccharide were done by standard methods and the anti-oxidant activity was measured by 1,1-diphenyl-2-picrylhydrazyl (DPPH) discoloration assay.Results: Our study reveals that the flower of both species contain highest amount of secondary metabolites in crude methanolic and aqueous extracts. In case of leaf, the methanolic extracts contain higher amount of polyphenol, flavonoid and anti-oxidant property in comparison to aqueous extracts, where as the aqueous extract contain higher amount of polysaccharide content than its counterpart. In stem, crude organic extract has higher amount of polyphenol and flavonoid and the aqueous extract has higher amount of polysaccharide and anti-oxidant property.Conclusion: The flower of Allamanda cathartica and Allamanda blanchetii has higher amount of flavonoids, polyphenols, polysaccharide and the floral extracts display comparatively higher anti-oxidant property.

scholarly journals In-situ measurement of reactive hydrocarbons at Hohenpeissenberg with comprehensive two-dimensional gas chromatography (GC×GC-FID): use in estimating HO and NO<sub>3</sub>

2007 ◽  
Vol 7 (1) ◽  
pp. 1-14 ◽  
Author(s):  
S. Bartenbach ◽  
J. Williams ◽  
C. Plass-Dülmer ◽  
H. Berresheim ◽  
J. Lelieveld
Keyword(s):  
Gas Chromatography ◽  
Mean Value ◽  
Gas Chromatography Mass Spectrometry ◽  
Two Dimensional ◽  
Time Data ◽  
Night Time ◽  
Diurnal Cycles ◽  
Meteorological Observatory ◽  
The Relationship

Abstract. During a field campaign at the Meteorological Observatory Hohenpeissenberg (MOHp) in July 2004, volatile organic compounds (VOCs) were measured using comprehensive two-dimensional gas chromatography (GC×GC). Comparison to routinely made gas chromatography mass spectrometry (GC-MS) measurements showed good agreement for a variety of anthropogenic and biogenic ambient VOCs ranging in concentration from below the detection limit (0.1 pmol mol−1) to 180 pmol mol−1. Pronounced diurnal cycles were found for both the biogenic and anthropogenic compounds, driven for the most part by the daily rise and fall of the boundary layer over the station. For the reactive compounds (lifetimes <2 days), a significant, non-zero dependency of the variability on lifetime was found, indicating that chemistry (as opposed to transport alone) was playing a role in determining the ambient VOC concentrations. The relationship was exploited using a single-variate analysis to derive a daytime mean value of HO (5.3±1.4×106molecules cm−3), which compares well to that measured at the site, 3.2±2.3×106molecules cm−3. The analysis was extended to the night time data to estimate concentrations for NO3 (1.47±0.2×108molecules cm−3), which is not measured at the site. The feasibility of this approach for environments dominated by emissions of short-lived VOCs to estimate ambient levels of radical species is discussed.

scholarly journals Comprehensive two-dimensional gas chromatography (GC×GC) measurements of volatile organic compounds in the atmosphere

2003 ◽  
Vol 3 (1) ◽  
pp. 1139-1181 ◽  
Author(s):  
X. Xu ◽  
L. L. P. van Stee ◽  
J. Williams ◽  
J. Beens ◽  
M. Adahchour ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Retention Indices ◽  
Two Dimensional ◽  
Ground Station ◽  
Flame Ionization ◽  
Peak Identification ◽  
Volatile Organic

Abstract. During the MINOS campaign in August 2001 comprehensive two-dimensional gas chromatography (GC×GC) was applied to the in situ measurements of atmospheric volatile organic compounds (VOCs) at the Finokalia ground station, Crete. The measurement system employs a thermal desorption unit for on-line sampling and injection, and a GCxGC separation system equipped with a flame ionization detector (FID) for detection. The system was optimized to resolve C7−C14 organic components. Two-dimensional chromatograms from measurements of Finokalia air samples show several hundred well-separated peaks. To facilitate peak identification, cartridge samples collected at Finokalia were analyzed using the same GC×GC system coupled with a time-of-flight mass spectrometer (TOF-MS). The resulting mass spectra were deconvoluted and compared to spectra from a database for tentative peak identification. About 650 peaks have been identified in the two-dimensional plane, with significant signal/noise ratios (>100) and high spectra similarities (>800). By comparing observed retention indices with those found in the literature, 235 of the identifications have been confirmed. 150 of the confirmed compounds show up in the C7−C14 range of the chromatogram from the in situ measurement. However, at least as many peaks remain unidentified. For quantification of the GCxGC measurements, peak volumes of measured compounds have been integrated and externally calibrated using a standard gas mixture.

Thermal desorption comprehensive two-dimensional gas chromatography for in-situ measurements of organic aerosols

2008 ◽  
Vol 1186 (1-2) ◽  
pp. 340-347 ◽  
Author(s):  
Allen H. Goldstein ◽  
David R. Worton ◽  
Brent J. Williams ◽  
Susanne V. Hering ◽  
Nathan M. Kreisberg ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Thermal Desorption ◽  
Organic Aerosols ◽  
In Situ Measurements ◽  
Two Dimensional

scholarly journals Comprehensive two-dimensional gas chromatography (GC × GC) measurements of volatile organic compounds in the atmosphere

2003 ◽  
Vol 3 (3) ◽  
pp. 665-682 ◽  
Author(s):  
X. Xu ◽  
L. L. P. Stee ◽  
J Williams ◽  
J. Beens ◽  
M. Adahchour ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Retention Indices ◽  
Two Dimensional ◽  
Ground Station ◽  
Peak Identification ◽  
Volatile Organic ◽  
Gc X Gc

Abstract. During the MINOS campaign in August 2001 comprehensive two-dimensional gas chromatography (GC x GC) was applied to the in situ measurements of atmospheric volatile organic compounds (VOCs) at the Finokalia ground station, Crete. The measurement system employs a thermal desorption unit for on-line sampling and injection, and a GC x GC separation system equipped with a flame ionization detector (FID) for detection. The system was optimized to resolve C7-C14 organic components. Two-dimensional chromatograms from measurements of Finokalia air samples show several hundred well-separated peaks. To facilitate peak identification, cartridge samples collected at Finokalia were analyzed using the same GC x GC system coupled with a time-of-flight mass spectrometer (TOF-MS). The resulting mass spectra were deconvoluted and compared to spectra from a database for tentative peak identification. About 650 peaks have been identified in the two-dimensional plane, with significant signal/noise ratios (>100) and high spectra similarities (>800). By comparing observed retention indices with those found in the literature, 235 of the identifications have been confirmed. 150 of the confirmed compounds show up in the C7-C14 range of the chromatogram from the in situ measurement. However, at least as many peaks remain unidentified. For quantification of the GC x GC measurements, peak volumes of measured compounds have been integrated and externally calibrated using a standard gas mixture.

Thermal Desorption Comprehensive Two-Dimensional Gas Chromatography: An Improved Instrument for In-Situ Speciated Measurements of Organic Aerosols

2012 ◽  
Vol 46 (4) ◽  
pp. 380-393 ◽  
Author(s):  
David R. Worton ◽  
Nathan M. Kreisberg ◽  
Gabriel Isaacman ◽  
Alexander P. Teng ◽  
Christopher McNeish ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Thermal Desorption ◽  
Organic Aerosols ◽  
Two Dimensional

Formation and Electric Properties of Disordered Yb Layers on Si(111)7×7 Surface

2003 ◽  
Vol 770 ◽  
Author(s):  
Nickolay G. Galkin ◽  
Dmitrii L. Goroshko ◽  
Alexander S. Gouralnik ◽  
Sergei A. Dotsenko ◽  
Andrei N. Boulatov
Keyword(s):  
Room Temperature ◽  
Hole Concentration ◽  
Hole Mobility ◽  
Growth Stages ◽  
Two Dimensional ◽  
Interface Formation ◽  
Dimensional Growth ◽  
2D And 3D ◽  
Semiconductor Type

AbstractInterface formation in Yb/Si(111) system has been investigated by AES and EELS spectroscopy and in situ Hall measurements at room temperature. It was found that interface formation process may be divided into five stages: 1) two-dimensional growth of Yb, 2) intermixing and formation of two-dimensional Yb silicide, 3) formation of 3D silicide islands, 4) growth of Yb on 3D silicide islands, 5) coalescence of 3D Yb – Yb silicide islands and formation of continuos Yb film. We attribute the observed character of conductivity in Yb/Si(111) system to the evolution of morphological and electrical properties of the growing Yb layer (2D Yb, silicide, metal) rather than to the changes within the space charge layer under the surface. Some amplitude oscillations have been observed in sheet conductivity, hole mobility and surface hole concentration within the coverage range below 6 ML where formation of a continuos Yb silicide film completes. Conductivity oscillations are explained by transition from semiconductor-type conductivity at the first growth stages (two-dimensional Yb growth) to metal-like conductivity of 2D and 3D Yb silicide films.

Sign in / Sign up

Export Citation Format

Share Document