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1.
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   

2.
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   

3.
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   

4.
陈华  辛广  张兰杰  张博 《分析试验室》2008,27(2):111-114
采用水蒸汽蒸馏法分别从未处理和纤维素酶前处理的没药中提取挥发油,利用气相色谱-质谱(GC/MS)联用技术对其挥发油成分进行分析。从中分别鉴定出38种和34种化学成分,用峰面积归一法通过数据处理系统得出各化学成分在挥发油中的质量分数,占挥发油总成分的67.95%和70.05%。  相似文献   

5.
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   

6.
Automation of the GC/MS analysis of mineral oil contaminations in water   总被引:1,自引:0,他引:1  
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   

7.
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   

8.
野西瓜种子油中脂肪酸的气相色谱-质谱分析   总被引:2,自引:0,他引:2  
采用加速溶剂萃取及索氏提取法,用正己烷和乙醚为提取剂从野西瓜种子中提取油脂,经浓H2SO4催化,甲醇甲酯化处理后,以气相色谱-质谱联用技术鉴定出野西瓜种子中的脂肪酸主要组成为:油酸、亚油酸、硬脂酸等,其中不饱和脂肪酸总量占91.4%,主要成分油酸占73.3%。野西瓜种子油具有较高的营养价值,同时也可为生物柴油提供良好的原料。  相似文献   

9.
双花千里光花精油的GC-MS分析   总被引:1,自引:0,他引:1  
采用气相色谱-质谱联用技术对西藏药用植物双花千里光的花精油进行化学成分分析,共分离出100余个峰,鉴定出其中73个化合物,其含量占精油总量的89%以上。该花精油的成分主要为单萜、倍半萜和脂肪酸及其酯,其中大于2%的成分共有12个,占精油总量的约70%。  相似文献   

10.
11.
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   

12.
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   

13.
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   

14.
GC/MS 法测定超临界 CO2 萃取茼蒿籽油   总被引:2,自引:0,他引:2  
利用GC/MS分析了超临界CO2萃取茼蒿籽油的成分组成,共检出32种成分。茼蒿籽油主要由亚油酸(含量68.32%)、棕榈酸(10.80%)、油酸(6.39%)和长碳链脂肪酸组成;茼蒿籽油还含甾类(4.76%)和丰富的维生素E(3.9mg/g);研究了茼蒿籽油的理化特征。  相似文献   

15.
柚皮蒸馏产物的GC/MS分析   总被引:4,自引:0,他引:4  
用水蒸气蒸馏法对柚皮外果皮进行了挥发性成分提取。用GC/MS分析法进行了分离鉴定,初步分离出50余个峰,鉴定了44种物质,用面积归一法测定其质量分数。在被测物质中,烃类化合物有13种和含氧有机化合物有31种,主要物质为柠檬烯(75.09%),α 蒎烯(0.84%),β 月桂烯(6.71%),芳樟醇(1 08%),芳樟酯(1.43%),萘酮(4.89%)。  相似文献   

16.
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   

17.
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   

18.
19.
本实验利用GC/MS电子轰击电离和化学电离两种方法对马面鲀鱼油中饱和、不饱和脂肪酸(经甲酯化后)进行了测定,用色谱法作了定量,共鉴定出16种脂肪酸。  相似文献   

20.
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