Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
enabled [disable] Abstract
Number of results

Results found: 15

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

Search:
in the keywords:  GC-MS
help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
EN
The various microextraction techniques have been developed in order to reduce sample preparation time, improve sensitivity and selectivity as well as to corroborate the recent advances in the development of highly sensitive and efficient analytical instrumentation. The current trend is aimed at the simplification and miniaturization of extraction steps, which has led to the combination of multi-step extraction and analytical analysis into single uninterrupted step. The method development involves the screening and subsequent optimization of both gas chromatography-mass spectrometry (GC-MS) and solid phase microextraction (SPME) parameters using multivariate experimental design, which has been shown to be efficient and effective with little experimental runs. The use of microextraction has been very effective in the analysis of contaminants in food, water and the environments to ensure they are safe and does not pose any health risk to human.
EN
Mosquitocidal activity of Phyla nodiflora methanol leaf extract fractions (Pn-MLEFr) was controlled and using main components on malarial vector, Anopheles stephensi (An. stephensi). Pn-MLE were characterized utilizing tools containing TLC, CC, FTIR and GCMS, and it against 3rd instars larvae of An. stephensi, followed by pupicidal activity was determined to concentration of 1, 3, 5 ppm. In phytochemical, characterized by GCMS analysis was carried out to be eligible for the constituents of the MLE. Pn-MLE Fr-6 showed the highest LC50 and LC90 values of 25.80 and 68.45 ppm, respectively. Fr-6 was found to be most effective for this activity provided pupa stage at death and stage of non-mortality values were 22.85 (NDP), 76.1 (TDP), 1.2 (DP), 0.7 (DA), 78% (TM%) and 6.6 (NAE), 22 (AE%) at 1 ppm against An. stephensi. Moreover, 3 and 5 ppm were provided TM% and AE% values of 94.43% and 5.57%; 100% and no adults emerged. In GC-MS analyzes, a total of 21 compounds were identified in the Pn-MLE, the main component was Ergosta-5,22-dien-3-ol, acetate, (3á,22E)-. Further, the AgNPs synthesized using Fm-ALE showed enhanced anti-bacterial activity. The reports revealed the Ergosta-5,22-dien-3-ol, acetate, (3á,22E)- was the most one of the important a compound provides malarial vector control from Pn-MLEFr.
EN
Garcina kola leaves were collected, washed, dried and powdered. The ethanol extracts were first prepared by the simple method of cold extraction. The extracts were then characterized by the Phytochemical analysis, Fourier transform infrared spectroscopy (FTIR) and Gas chromatography mass spectroscopy (GC-MS) to identify the fatty acids and heterocyclic compounds present in the leaf extracts. The FTIR analysis shows a variation of the peaks that indicate there is synergy among the functional groups of the extract. Moreover, the phytochemical analysis revealed the presence of alkaloids, flavonoids, phenol, saponins, tannins and steroids. The study reveals that the chemical constituents of Garcina kola leaf may be behind their medicinal values in phytomedicine.
EN
Thermal and catalytic degradation of polystyrene waste over two different samples of natural volcanic tuff catalyst comparative with Florisil catalyst has been carried out in order to establish the conversion degree into styrene monomer. The polystyrene waste (PS) was subjected to a thermal degradation process in the range of 380–500°C in presence of studied catalysts in a ratio of 1/10 in mass, catalyst/PS. The catalysts were characterized by N2 adsorption-desorption isotherms (BET), Scanning Electron Microscopy (SEM) and Fourier-transform infrared spectrometry (FTIR). Influences of temperature and type of catalysts on the yields and on the distribution of end-products obtained by thermal and catalytic degradation of polystyrene waste have been studied. The maximum yields of liquid products were obtained at 460°C degradation temperature and were calculated between 83.45% and 90.11%. The liquid products were characterized by gas chromatography mass spectrometry (GC-MS) and FTIR analytical techniques. The GC-MS results showed that the liquid products contained styrene monomer up to 55.62%. The FTIR spectra of liquid products indicated the specific vibration bands of the functional groups of compounds of liquid products. The amounts of styrene monomer obtained were influenced by structural and textural properties of studied catalyst and the contribution on product distribution is discussed. [...]
EN
Desloratadine is a biologically active compound that is not described in the Polish Pharmacopoeia IX, hence, its study is particular important. The aim of this work was to establish a procedure for desloratadine analysis by way of HPTLC in combination with densitometry, so as to be able to ascertain its presence and degree of presence within pharmaceutical preparations. In our work, a mixture of ethyl acetate, n-butanol, ammonia and methanol was used as the mobile phase. Moreover, HPTLC plates precoated with silica gel 60F254 were also employed. The proposed method was tested and subsequently validated. Spectrodensitometric analysis was then performed to determine the optimal wavelength for the quantitative determination (λ=276 nm), and following this, a quantitative analysis of desloratadine within certain pharmaceutical preparations was performed. Our research also took into consideration an analysis of the products of desloratadine decomposition that come about as a result of the accelerated aging of its solutions. The employed procedure for accelerating the aging of such desloratadine solutions consisted of heating these at 40℃ and then irradiating the solution surfaces with UV light. The changing color of these solutions after 2 hours of exposure served to indicate that degradation had occurred. Of note: as a result of irradiation with UV light, desloratadine content was seen to decrease with time, declining to almost zero after 30 hours. However, heating a solution of desloratadine alone did not induce a change in its content. Solutions of desloratadine that had previously undergone irradiation and heating were also analyzed to ascertain whether new substances were present. For this purpose, the GC-MS process was employed. As a result of this procedure, the spectrum of the solution after aging showed the presence of several new peaks that displayed retention several times larger and smaller than the normal desloratadine peak.
EN
The methanol extract of the aerial parts of Celosia trigyna (Amaranthaceae) was successively fractionated using n-hexane, dichloromethane, ethyl acetate and n-butanol. The cytotoxic activity of the obtained fractions was investigated using sulphorhodamine-B (SRB) assay against three carcinoma cell lines; breast adenocarcinoma (MCF-7), colorectal carcinoma (HCT-116) and hepatocellular carcinoma cells (HepG2). The dichloromethane fraction showed significant in vitro cytotoxic activities against the human cancer cell lines HCT-116 and HEP-G2 with IC50 values of 10.9 and 11.2 µg/mL, respectively, while all fractions revealed weak antioxidant activity using DPPH free radical scavenging method. The GC-MS analysis of the most cytotoxic dichloromethane fraction has resulted in the identification of 12 compounds. The main constituents were tetrahydroisoquinoline derivative (31.44%), 2,3-dimethylheptadecane (16.71%) and 3-octadecanone (15.56%). Moreover, the phytochemical study of the dichloromethane and n-butanol fractions led to the isolation and identification of five known compounds identified as β-amyrin acetate (1), acacetin 8-C-α-rhamnosyl-(1→2)-β-glucopyranoside (2), apigenin 8-C-α-rhamnosyl-(1→2)-β-glucopyranoside (3), quercetin 3-O-α-rhamnosyl-(1→6)-β-glucopyranoside (4) and 3-hydroxyglutaric acid (5).
EN
A clandestine two-step route to psychoactive racemic phenylalkylamines utilises the Henry reaction. In the first step an aromatic aldehyde reacts with a nitroalkane to give the nitrostyrene intermediate. In the second step the nitrostyrene is reduced to the phenylalkylamine. An impurity profile of both steps was evaluated through the synthesis and analysis of common street derivatives. The formation of nitrile impurities in the nitroaldol reaction and hydroxylamine impurities in the reduction step were shown by NMR spectroscopy and GC-MS. A selection of reducing agents has been used to give the phenylalkylamines, together with variable quantities of the partially reduced hydroxylamine product. GC-MS analysis of the hydroxylamines showed heat-induced disproportionation which led to the detection of the corresponding oximes. [...]
8
Content available remote

GC-MS fingerprints of mint essential oils

75%
EN
Essential oils from eleven Mentha species were obtained by Deryng hydrodistillation and analysed by GC–MS: 44 compounds were identified. The most abundant were menthone, isomenthone, menthol, carvone, piperitone oxide, D-limonene and eucalyptol. Chemometric similarity measures and principal component analysis were calculated, allowing comparisons based on secondary metabolite content. The fingerprints may be helpful in chemotaxonomy.
EN
The essential oils (EOs) and static headspaces (HSs) of in vitro plantlets and callus of Mentha x piperita were characterized by GC-MS analysis. Leaves were used as explants to induce in vitro plant material. The EO yields of the in vitro biomass were much lower (0.1% v/w) than those of the parent plants (2% v/w). Many typical mint volatiles were emitted by the in vitro production, but the callus and in vitro plantelet EOs were characterized by the lack of both pulegone and menthofuran. This was an important difference between in vitro and in vivo plant material as huge amounts of pulegone and menthofuran may jeopardise the safety of mint essential oil. Regarding the other characteristic volatiles, menthone was present in reduced amounts (2%) in the in vitro plantlets and was not detected in the callus, even if it represented the main constituent of the stem and leaf EOs obtained from the cultivated mint (26% leaves; 33% stems). The M. piperita callus was characterized by menthol (9%) and menthone (2%), while the in vitro plantlet EO showed lower amounts of both these compounds in favour of piperitenone oxide (45%). Therefore, the established callus and in vitro plantlets showed peculiar aromatic profiles characterized by the lack of pulegone and menthofuran which have to be monitored in the mint oil for their toxicity.
EN
Few studies have shown that Cnestis ferruginea possess some therapeutic properties. The present study was aimed screening the extracts of the fruits and leaves of Cnestis ferruginea for phytochemicals using crude screening and gas chromatography-mass spectrophotometer (GC-MS) methods, and also antimicrobial activity against clinical isolates. Preparation of the extracts (aqueous and ethanolic), identification of isolates, and antimicrobial sensitivity were done using previously reported standard methodologies. Replicate readings for the antimicrobial sensitivity were analysed using analysis of variance at 95% level of significance. The result of the crude qualitative screening revealed the presence of phenol, terpenes, alkaloids, saponins, tannin and polyphenol in various amounts in both the leaves and fruits. Quantitative analysis using GC-MS revealed a total of 14 similar phytochemicals each in the leaves and fruits of the study plant in varying amounts. In the fruits, phenol had the highest concentration of 15.01%, followed by terpenes (10.64%), alkaloid (5.43%), and tannins (5.16%). Others were anthocyanins, phytate, phytosterol, steroids, saponins, cardiac glycosides, oxalate, flavonoids, cyanogenic glycosides and coumarin with concentrations that ranged from to 0.01- 4.21%. On the other hand, in the leaves, alkaloids had the highest concentration of 31.62%, followed by phenol (20.59%), phytate (15.18%), and tannin (12.34%). Others include were flavonoid, terpenes, phytosterol, cardiac glycosides, saponins, cyanogenic glycosides, oxalate, anthocyanins, steroids and coumarin with concentrations that ranged from 0.16-8.45%. The isolates were identified as Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa and Proteus spp. The results of the antimicrobial sensitivity revealed varying zones of inhibitions; however, it increased as the concentration of the extract increased. The observed highest zones of inhibitions were 33.86 mm for the fruit ethanolic extract and 30.56 mm for the aqueous extract of the leaves against Proteus and Staphylococcus aureus, respectively.
EN
In vitro plantlets and callus of M. longifolia were established and their volatile constituents characterized by GC-MS analysis of their headspaces (HSs) and essential oils (EOs). Significant quali-quantitative differences were found in the aromatic fingerprints in comparison with the M. longifolia parent plants. In fact, limonene and carvone were the main constituents in the EOs of the mother plants, while the aroma of the in vitro plant material were especially enriched in oxygenated terpenes. In particular, huge amounts of piperitenone and piperitenone oxide (75 %) were found for in vitro plantlets, while trans-carvone oxide (19 %) and trans-piperitone epoxide (9 %) were found in callus EO. However, the established in vitro plant material showed lack of pulegone and menthofurane, thus preserving an important feature observed in the volatile fingerprint of the parent plants. In fact, because of their well-known toxicity significant amounts of pulegone and menthofurane may compromise the safety using of mint essential oil. Therefore the in vitro M. longifolia plantlets and callus may be regarded as a potential source of a safe flavouring agent.
EN
This study analyzed chemical composition of the essential oils (EOs) of Thymus vulgaris L., harvested in two regions of northwest Algeria (Tlemcen and Mostaganem), and evaluated their antimicrobial and cytotoxic activity. Fifty one compounds representing 99.99% and 100% of total thyme oil of Mostaganem (EO.TM) and Tlemcen (EO.TT), respectively were identified by GC-FID and GC-MS. Carvacrol was a dominant compound in both oils (89.15 and 82.42%). The antimicrobial activity, demonstrated by disc diffusion and broth macrodilution methods, showed a strong inhibitory effect of the oils on seven reference strains tested and particularly on Bacillus cereus ATCC 10876 and Candida albicans ATCC 10231. A cytotoxicity assay for two normal and two cancer cell lines indicated the highest sensitivity of canine B-cell lymphoma cell line (CLBL-1) for which IC50 values were 35.39 ± 9.0 (EO.TT) and 84.51± 3.2 (EO.TM). Murine fibroblast cell line (3T3), with IC50 116.97 ± 2.7 for EO.TT and 146.29 ± 0.5 for EO.TM was the most resistant line.
EN
Aromatic plant species present in the natural Park of Tuscany Archipelago are used as flavoring agents and spices, as dietary supplements and in cosmetics and aromatherapy. The plants are usually collected from wild stands, inducing a depletion of the natural habitat. Therefore, micropropagation of these aromatic plants can play a role in the protection of the natural ecosystem, can guarantee a massive sustainable production and can provide standardized plant materials for diverse economical purposes. The aim of this study is to compare the volatile organic compounds produced by the wild plants with those from in vitro plantlets using headspace solid phase micro-extraction (HS-SPME) followed by capillary gas-chromatography coupled to mass spectrometry (GC-MS). Typical plants of this natural area selected for this work were Calamintha nepeta L., Crithmum maritimum L., Lavandula angustifolia L., Myrtus communis L., Rosmarinus officinalis L., Salvia officinalis L. and Satureja hortensis L. Different explants were used: microcuttings with vegetative apical parts, axillary buds and internodes. Sterilization percentage, multiplication rate and shoot length, as well as root formation were measured. The volatile aromatic profiles produced from in vitro plantlets were compared with those of the wild plants, in particular for C. maritimum, R. officinalis, S. officinalis and S. hortensis. This study indicated that the micropropagation technique can represent a valid alternative to produce massive and sterile plant material characterised by the same aromatic flavour as in the wild grown plants.
EN
Abstract An attempt has been made to selectively oxidise synthetic lignin-like polymer for fine chemicals. The G- and S-type polymers (G- and S- type lignin model polymers) were synthesized using simple aromatic compounds as starting materials and then oxidised to benzaldehydes by reacting them with Co(salen) catalytic system. The reaction was characterized by measuring the change of the polymer with FTIR, C-13 NMR and GC-MS spectroscopy. The results obtained by the FTIR and C-13 NMR showed that the effects of NaOH were important and higher yield of benzaldehydes characterized by GC-MS in the presence of NaOH in the course of catalytic oxidation of the polymer demonstrated these effects. From the results, the catalyst could suitably be used in green procedures for lignin transformation.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.