Qualitative GC-MS Research Articles

Glandular Trichomes, Secretory Cavities and Essential Oil of Sage (Salvia officinalis L.)

The purpose of the present work was to provide new elements on the localization of Salvia officinalis essential oil secretory structures. Anatomical investigations of leaves and stems secretory structure were carried out using light microscopy. Non-glandular, peltate and four types capitate glandular trichomes, already described in the literature, were found. In other hand, the parenchyma histological study showed the occurrence of oil secretory cavities. The kinetics of hydrodistillation is in agreement with the presence of essential oil produced and stored in endogenous cavities of S. officinalis. The qualitative and quantitative GC and GC-MS analysis of the essential oil revealed α-thujone (12.6 %), viridiflorol (12.5 %), β-caryophyllene (11.7 %) and α-humulene (10.3 %) as the major constituents.

Comparison of phytochemical composition of medicinal plants by means of chromatographic and related techniques

In this article a comparative study results on amount of biologically active compounds and composition of raw material of diploidal medicinal plants of threelobe beggarticks (Bidens tripartita L.), fenugreek (Trigonella foenum-graecum L.), milk thistle (Silybum marianum L.) and marigold (Calendula officinalis L.) and experimentally created their polyploidal meristems are presented. The total content of phenolics and flavonoids in the plant methanolic extracts was analyzed spectrophotometrically. Antioxidant activity was determined and expressed in percents of conjugated DPPH radical. For quantitative and qualitative analysis CE, HPLC and GC-MS methods were used. Antioxidant activity of experimentally created polyploidal forms extracts comparing to reference samples in all cases was higher except extracts of Silybum marianum L. It was obtained, that primary diploidal and created polyploidal forms of medicinal plants investigated differ not only in quantitative composition but also in qualitative composition.

Rapid qualitative pyrolysis GC-MS analysis of carcinogenic aromatic amines from dyed textiles

A rapid and simple method, pyrolysis gas chromatography coupled with mass spectrometric detection (Py-GC-MS), is introduced for qualitative determination of banned aromatic amines released from azo dyes on textiles. Use of Py-GC-MS can reduce absolute analysis time from three hours to thirty minutes, because no sample preparation is necessary. Qualitative determination of banned amines by Py-GC-MS was investigated for three pure azo dyes and six contaminated textile samples consisting of different matrices. Pyrolysates of pure azo dyes were identified as aromatic amines. Banned aromatic amines released from azo dyes could be qualitatively determined for four of six contaminated textile samples by Py-GC-MS.

Aroma components of an oil-based grill flavoring by direct thermal desorption-gas chromatography-olfactometry and sample dilution analysis.

Grill flavorings are a convenient way for food processors to impart grill-like flavor to meat products that have not been grilled. In this study a commercially available oil-based processed grill flavoring was analyzed by direct thermal desorption (DTD)-gas chromatography-olfactometry (GCO) and DTD-GC-mass spectrometry (MS). Sample mass dilution analysis-GCO was used to indicate which compounds had the greatest impact on the overall aroma of the sample. Major aroma contributors included 1-octen-3-one, 2-methoxyphenol, and (E)-2-nonenal. Minor contributors were (E)-2-decenal and 2,4-decadienal. Other major contributors, characterized as having grill aroma notes, were unidentified. Excluding the possibility of artifact formation from the thermal degradation of fatty acid hydroperoxides, DTD functioned well as a GCO technique, but poorly as a qualitative GC-MS technique.

Validation of urine drug-of-abuse testing methods for ketobemidone using thin-layer chromatography and liquid chromatography–electrospray mass spectrometry

High-performance thin-layer chromatography (TLC) with visual detection (post-chromatographic derivatization) was used in screening for the drug ketobemidone in human urine samples. High-performance liquid chromatography with electrospray mass spectrometry (LC–ESI–MS) was used for final confirmation of the result. The clean-up was performed by mixed-mode solid-phase extraction, and nalorphine was used as internal standard. A screening cut-off for TLC was established at 0.2 μg/ml. The mean recovery for LC–MS was 91% ( n=60) with coefficients of variation (C.V.) in the range of 7 to 16%. Qualifying fragment ions of ketobemidone ( m/z 190, 201 and 230) were generated by up front collision-induced dissociation (CID) on a single quadrupole instrument. Relative ion intensities were within ±15% deviation compared with standards in the same batch. The limit of detection for LC–MS was 0.025 μg/ml. Positive clinical samples from drug abusers ( n=10) had concentrations in the range 0.07 to 3.2 μg/ml, which could be determined by LC–MS without matrix interference. During screening of unknown clinical samples ( n=27) the results from TLC was in agreement with LC–MS data. After acid hydrolysis of conjugates in clinical samples the analyte response of ketobemidone and norketobemidone was increased by a factor of approximately two and twelve, respectively. A qualitative GC–MS technique was demonstrated for the detection of the spasmolyticum A29 (N, N-dimethyl-4,4-diphenyl-3-buten-2-amine), which can be found in a preparation combined with ketobemidone (Ketogan).

Structural and Histochemical Investigation of the Glandular Trichomes ofSalvia aureaL. Leaves, and Chemical Analysis of the Essential Oil

Abstract Anatomical and histological investigations of the secretory hairs of Salvia aurea leaves, and identification of the main components of the essential oil were carried out. Two types of glandular trichome were found: peltate glands, characterized by a short stalk and a large six to eight-celled head, and capitate trichomes which were further subdivided into two kinds, the first with a short monocellular stalk and two-cellular head (type I), and the second with a multicellular stalk, a neck cell and a small globose unicellular head (type II). Whereas peltate glands and type I capitate trichomes were always present, type II capitate glands were not found in all leaf samples. The histochemical study suggested an ‘endodermal’ role for the stalk cell (peltate and capitate type I) as well as for the neck cell (capitate type II), preventing the loss of essential oil. Histological reactions also revealed the complex nature of the material secreted by all types of S. aurea trichome, including polysaccharides, polyphenols and proteins, in addition to the essential oil. Qualitative and quantitative GC-MS analysis of the essential oil revealed camphor to be the main constituent. The findings are discussed in relation to studies of trichomes from other members of the Lamiaceae.

Application of 13C-labelled polychlorinated biphenyl congener 153 as internal standard in the gas chromatographic-mass spectrometric analysis of polychlorinated biphenyls

We developed a method of qualitative and quantitative GC-MS analysis of polychlorinated biphenyls (PCBs) in soil samples, to be able to determine the biodegradation efficiency for individual PCBs. 13C 12-Substituted PCB 153 was used as internal standard. The analyses were performed on a DB-5 capillary column. The identification procedure was based on the correlation analysis of the measured and published relative retention r 12 data using [ 13C 12]PCB 153 instead of octachloronaphthalene (OCN). [ 13C]PCB 153 was also used for quantification of individual PCBs in soil samples.

Glandular trichomes and essential oil constituents ofCalamintha menthifolia (Lamiaceae)

Plant material ofCalamintha menthifolia was collected from two populations grown in the Vikos-Aoos area (NW. Greece). The structure and ontogeny of the glandular trichomes and the chemical composition of the secreted essential oil were studied. The leaves ofC. menthifolia have numerous glandular trichomes of three morphological distinct types: 1) glandular scales with a unicellular foot and stalk, and a 12-celled head, 2) glandular hairs with a unicellular foot and stalk, and a unicellular pear-shaped head and 3) glandular hairs with a unicellular foot, a bicellular stalk and a unicellular elongated head. Qualitative and quantitative GC-MS analyses of the essential oils revealed piperitone oxide as the main constituent in both populations. In the light of these results the relationships beweenC. menthifolia and other members of theSatureja group as well as its taxonomy are discussed.

Analysis of coal conversion recycle solvents by liquid chromatography with nuclear magnetic resonance detection

The analyses of two coal conversion recycle process solvents, one of them hydrotreated, via high-performance liquid chromatography (HPLC) with a continuous flow nuclear magnetic resonance (NMR) detector are reported. The differences between these samples with reference to the role of the solvent in coal liquefaction are discussed. The LC-/sup 1/H NMR technique characterized the hydrocarbons and aromatic ethers with a level of certainty not possible with conventional detectors. In addition, qualitative GC-MS analysis of off-line LC fractions was performed on the recycle solvent sample. LC-/sup 1/H NMR and LC-GC-MS were found to be complementary for volatile samples. Gel permeation chromatography-/sup 1/H nuclear magnetic resonance (GPC-/sup 1/H NMR) analysis of the recycle solvent sample was not as successful as LC-/sup 1/H NMR since class separation is almost essential for this sample. But the introduction of GPC-/sup 1/H NMR is still of interest since GPC is the most appropriate mode of separation for many samples.