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Boutaghane N Kabouche A Touzani R Maklad YA El-Azzouny A Bruneau C Kabouche Z 《Natural product communications》2011,6(2):251-252
The essential oil of Matricaria pubescens (Asteraceae) collected at Ghardaia (Algerian Septentrional Sahara) was studied by GC and GC-MS. Isochrysanthemic acid ethyl ester (26.5%), spathulenol (19.4%), alpha-cadinol (12.9%) and geranylisovalerate (8.2%), were identified as the major components of the essential oil, which was investigated for its analgesic effect. 相似文献
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Paulius Kaškonas Žydrūmas Stanius Vilma Kaškonienė Kęstutis Obelevičius Ona Ragažinskineė Antanas žilinskas Audrius Maruška 《Chemical Papers》2016,70(12):1568-1577
This study describes the analysis of total hops essential oils from 18 cultivated varieties of hops, five of which were bred in Lithuania, and 7 wild hop forms using gas chromatography-mass spectrometry. The study sought to organise the samples of hops into clusters, according to 72 semi-volatile compounds, by applying a well-known method, k-means clustering analysis and to identify the origin of the Lithuanian hop varieties. The bouquet of the hops essential oil was composed of various esters, terpenes, hydrocarbons and ketones. Monoterpenes (mainly β-myrcene), sesquiterpenes (dominated by β-caryophyllene and α-humulene) and oxygenated sesquiterpenes (mainly caryophyllene oxide and humulene epoxide II) were the main compound groups detected in the samples tested. The above compounds, together with a-muurolene, were the only compounds found in all the samples. Qualitative and quantitative differences were observed in the composition of the essential oils of the hop varieties analysed. For successful and statistically significant clustering of the data obtained, expertise and skills in employing chemometric analysis methods are necessary. The result is also highly dependent on the set of samples (representativeness) used for segmentation into groups, the technique for pre-processing the data, the method selected for partitioning the samples according to the similarity measures chosen, etc. To achieve a large and representative data set for clustering analysis from a small number of measurements, numerical simulation was applied using the Monte Carlo method with normal and uniform distributions and several relative standard deviation values. The grouping was performed using the k-means clustering method, employing several optimal number of clusters evaluation techniques (Davies-Bouldin index, distortion function, etc.) and different data pre-processing approaches. The hop samples analysed were separated into 3 and 5 clusters according to the data filtering scenario used. However, the targeted Lithuanian hop varieties were clustered identically in both cases and fell into the same group together with other cultivated hop varieties from Ukraine and Poland. 相似文献
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Paolini J Tomi P Bernardini AF Bradesi P Casanova J Kaloustian J 《Natural product research》2008,22(14):1270-1278
The composition of the essential oil of Cistus albidus (L.) obtained from plants growing wild in Provence (France) has been investigated using GC-RI (RI = retention indices), GC/MS and (13)C-NMR. Eighty-eight components were reported accounting for 81.8% of the essential oil. This essential oil was characterized by a high content of sesquiterpenes with alpha-zingiberene (12.8%), alpha-curcumene (7.7%), (E)-beta-caryophyllene (5.9%), alpha-cadinol (5.4%), alpha-bisabolol (4.1%), caryophyllene oxide (3.8%), allo-aromadendrene (3.4%), delta-cadinene (3.4%), and germacrene D (3.1%) being the main components. 相似文献
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An automation of the sample preparation and analysis of mineral oil contaminations in water was developed. The automated sample preparation was carried out according to ISO/DIS 9377-4 [1]. The standard is applicable to the determination of hydrocarbons in the boiling range of n-decane (n-C10) up to n-tetracontane (n-C40) by GC. Extraction of the sample and clean-up of the extract were performed by an autosampler with a movable head which is capable of carrying different syringes for gas and liquid handling. A GC/MS-system with a programmed temperature vaporizing (PTV) injector including the possibility of large volume injections (LVI) was employed for the analysis. The recovery of analytes was 101.8%, the repeatability 2.9% relative standard deviation (RSD). The linear range covered 0.3 to 40 mg/L oil but may be larger since no higher concentrations were measured. With an FID, being the detector of choice mentioned in the standard, it should be possible to achieve at least four orders of magnitude in the linear range. The limit of determination was found to be 0.3-0.4 mg/L, the limit of detection 0.1-0.2 mg/L [2]. Measurements of spiked deionized, bidistilled water and spiked water from a lake confirmed the accuracy of the analysis. Due to automation and miniaturization of the analysis it is possible to economize time and chemicals without loss of precision and accuracy. 相似文献
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An automation of the sample preparation and analysis of mineral oil contaminations in water was developed. The automated
sample preparation was carried out according to ISO/DIS 9377–4 [1]. The standard is applicable to the determination of hydrocarbons
in the boiling range of n-decane (n-C10) up to n-tetracontane (n-C40) by GC. Extraction of the sample and clean-up of the
extract were performed by an autosampler with a movable head which is capable of carrying different syringes for gas and liquid
handling. A GC/MS-system with a programmed temperature vaporizing (PTV) injector including the possibility of large volume
injections (LVI) was employed for the analysis. The recovery of analytes was 101.8%, the repeatability 2.9% relative standard
deviation (RSD). The linear range covered 0.3 to 40 mg/L oil but may be larger since no higher concentrations were measured.
With an FID, being the detector of choice mentioned in the standard, it should be possible to achieve at least four orders
of magnitude in the linear range. The limit of determination was found to be 0.3–0.4 mg/L, the limit of detection 0.1–0.2
mg/L [2]. Measurements of spiked deionized, bidistilled water and spiked water from a lake confirmed the accuracy of the analysis.
Due to automation and miniaturization of the analysis it is possible to economize time and chemicals without loss of precision
and accuracy.
Received: 6 October 1999 / Revised: 6 December 1999 / Accepted: 10 December 1999 相似文献
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The bioactivity of the essential oil extracted by hydrodistillation from Lantana camara leaves was assessed under laboratory conditions. The composition of L. camara essential oil included large amounts of sesquiterpene, mainly β-caryophyllene (35.70%) and caryophyllene oxide (10.04%). The tested essential oil showed good fumigant activity within 1 week of exposure for all tested doses. Moreover, remanence study confirmed that the oil was efficient during 2 weeks. 相似文献
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A simplified fraction of the Oural crude oil (aliphatic and aromatic hydrocarbons) was incubated in the presence of an hydrocarbonoclastic bacterial community isolated from a marine sediment highly contaminated by petroleum residue. The biodegradation has been carried out under aerobic conditions for 5 weeks and followed by FTIR, UV synchronous luminescence and GC/FID. Disappearance of the n-alkanes (2nd week), an important attack of the isopreno?d compounds (5th week) and preferential alteration of monomethylated polyaromatics were observed. Concerning the biomarkers, the bicyclic alkanes and pentacyclic terpanes have been comparatively elucidated using GC/MS data. The identification of C(26) to C(29) steranes has required a most selective method, namely GC/MS/MS. Many molecular ratios based on GC/MS abundances were calculated, which showed good stability. Consequently, they can be used to determine the origin of a petroleum even one altered by biodegradation. 相似文献
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Summary The composition of the fragrance volatiles of fresh flowers has been determined using pre-column absorption-capillary gas
chromatography-mass spectrometry with the help of a specially constructed desorption device. Two species of fresh flowers,
Rosa Setate X Rosa Rugosa and Syringa oblata Lindl. var. alba Rehd, were chosen as examples in this investigation. 相似文献
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《Arabian Journal of Chemistry》2023,16(4):104641
The current investigation aimed to shed light in the volatile and non-volatile secondary metabolites of Ajuga orientalis L. from Jordan. GC/MS and GC/FID analysis of the hydrodistilled essential oil obtained from aerial parts of the plant revealed tiglic acid (18.90 %) as main constituent. Each of the methanol and butanol fractions of A. orientalis were screened for their total phenol content (TPC), total flavonoid content (TFC), and antioxidant activity determined by DDPH and ABTS methods. The extracts were then analyzed by LC-ESI-MS/MS to unveil their chemical constituents, especially phenols and flavonoids. Results showed that the AO-B extract had the highest TPC (217.63 ± 2.65 mg gallic acid/g dry extract), TFC (944.41 ± 4.77 mg quercetin /g dry extract), highest DPPH and ABTS antioxidant activity ((4.00 ± 0.20) × 10-2; (3.00 ± 0.20) × 10-2 mg/mL, respectively) as compared to the AO-M extract. LC-ESI-MS/MS analysis of both extracts revealed the presence of several phenolics, flavonoids and nonphenolic acids. 相似文献
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Wolfgang Vautz Luzia Seifert Sascha Liedtke Dietmar Hein 《International Journal for Ion Mobility Spectrometry》2014,17(1):25-33
Ion mobility spectrometry (IMS) is a well-known analytical method for the detection of CWAs and explosives since many years. Coupling IMS to GC pre-separation, new application fields in medicine and biology could be opened, dealing with complex and humid mixtures. However, identification of unknowns in such a complex sample is challenging and can only be achieved by parallel GC/MS analysis, thus obtaining a proposal for the responsible compound for validation via reference substances by GC/IMS again. The available adsorption tools for such accompanying GC/MS analysis have their particular drawbacks (e.g. problematic quantification for SPME, high sample volumes for adsorption tubes). Therefore miniaturised adsorption needles (NeedleTrap) were applied to both GC/IMS and GC/MS for validation of their reproducibility. It could be demonstrated that the needles can even be used for appropriate quantification when the adsorbent and the sample volume are adapted properly to the concentration range, the compounds of interest and humidity of the sample. The method is very flexible with regard to the concentration range by variation of the sample volume (e.g. 20 mL for pptV, 10 mL for lower ppbV or 1 mL for ppmV) and with regard to the compounds of interest by application of common adsorption materials optimised for the relevant substance group. Such materials are available commercially in a broad variability. Therefore, the miniaturised adsorption needles are a helpful complementary sampling method for any GC/MS or GC/IMS investigations. 相似文献
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调味品中氯丙醇的GC/ECD和GC/MS/MS衍生化检测方法研究及应用 总被引:8,自引:0,他引:8
报道了调味品中氯丙醇的衍生化气相色谱(GC/ECD)和衍生化气相色谱双串联质谱法(GC/MS/MS)测定。GC/ECD测定酱油中3—氯—1,2—丙二醇(3—MCPD)的检出限达到0.01mg/kg,回收率为91%~104%,变异系数为2.27%~7.96%;GC/MS/MS同时测定酱油中1,3—二氯—2—丙醇、2,3—二氯—1—丙醇和3—氯—1,2—丙二醇,1,3—二氯—2—丙醇、2,3—二氯—1—丙醇的检出限为0.02mg/kg,3—氯—1,2—丙二醇的检出限为0.01mg/kg,回收率在92%~106%,变异系数为3.51%~13.33%。 相似文献
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