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1.
The enantiomeric ratios of chiral volatile organic compounds in juniper‐flavored spirits produced by various processing technologies in different EU countries were determined by multidimensional GC using solid‐phase microextraction and liquid–liquid extraction as a sample pretreatment procedure. In total, more than 260 compounds were detected in studied spirits from which linalool, α‐terpineol, 4‐terpineol, linalool oxides, α‐pinene, and verbenone were selected for enantiomeric separation. The significant differences in enantiomeric ratio of linalool and cis‐linalool oxide allowed us to distinguish between samples produced in Slovakia and the United Kingdom from those produced in Germany, Czech Republic, and Belgium. The pure enantiomer of trans‐linalool oxide was found only in samples from Germany. It was shown that the enantiomeric ratio is independent of the sample treatment procedure, and only small differences up to 1% were observed.  相似文献   

2.
By alternate use of two different extraction solvents, n-hexadecane and benzyl alcohol, a headspace-solvent microextraction (HSME)–GC–FID/MS method has been established for characterization of the volatile components of an orange juice beverage. The method avoids two disadvantages of conventional HSME—difficulty identifying components obscured by the solvent peak and inefficient extraction of some of the compounds if one solvent only is used. The optimum conditions (droplet volume, equilibration temperature and time, extraction time, and ionic strength) were determined by the factor-rotation method. The volatile components of the beverage were mainly terpenes, terpenols, fatty acids, and alcohols, for example limonene (114.71 mg L−1), phellandrene (4.50 mg L−1), terpineol (p-menth-1-en-8-ol; 3.12 mg L−1), α-pinene (0.33 mg L−1), n-hexadecanoic acid (0.28 mg L−1), and terpinol (0.13 mg L−1).  相似文献   

3.
建立了间接顶空固相微萃取-气相色谱-质谱对红花香雪兰天然花香成分的分析方法。首先利用气体采样装置对花香成分进行固相富集,富集后的花香成分在浸提液中解析,之后利用顶空固相微萃取方法对浸提液中的花香成分进行分析。红花香雪兰花香中主要成分(沉香醇、松油醇、紫罗兰酮和二氢紫罗兰酮)定量分析优化实验条件:Florisil(弗罗里硅土)作为吸附剂,水-甲醇混合液(9∶1, V/V)和0.6 mol/L HCl作为浸提液,萃取温度70℃,平衡时间为25 min。实验结果表明,沉香醇和松油醇在1~100μg/mL范围内有良好的线性关系(R2≥0.981),检出限分别为0.05和0.10μg;二氢紫罗兰酮和紫罗兰酮在0.5~50μg/mL范围内有良好的线性关系(R2≥0.988),检出限为0.02μg。  相似文献   

4.
A novel sol–gel coating on a stainless‐steel fiber was developed for the first time for the headspace solid‐phase microextraction and determination of α‐bisabolol with gas chromatography and flame ionization detection. The parameters influencing the efficiency of solid‐phase microextraction process, such as extraction time and temperature, pH, and ionic strength, were optimized by the experimental design method. Under optimized conditions, the linear range was between 0.0027 and 100 μg/mL. The relative standard deviations determined at 0.01 and 1.0 μg/mL concentration levels (= 3), respectively, were as follows: intraday relative standard deviations 3.4 and 3.3%; interday relative standard deviations 5.0 and 4.3%; and fiber‐to‐fiber relative standard deviations 6.0 and 3.5%. The relative recovery values were 90.3 and 101.4% at 0.01 and 1.0 μg/mL spiking levels, respectively. The proposed method was successfully applied to various real samples containing α‐bisabolol.  相似文献   

5.
A simple, reliable and effective gas chromatography coupled with flame ionization detection method was developed for the simultaneous determination of eight components (α‐pinene, β‐pinene, myrcene, limonene, terpinen‐4‐ol, α‐terpineol, bornyl acetate and methyl‐n‐nonylketone) in Chinese medicine Houttuynia cordata and its injection. The chromatographic separation of all eight components, including undecylene as internal standard was performed on a DB‐1 column (30 m×0.25 mm, 0.25 μm). Excellent linear behaviors including herb and injection over the investigated concentration ranges were observed with the values of r2 higher than 0.9990 for all analytes. Satisfactory intra‐day and inter‐day precisions were achieved with RSD less than 2% and the average recoveries for all analytes at three different concentrations obtained were in the range of 93.4–104.4%, with RSD ranging from 1.3 to 4.1%. The proposed method was successfully applied in the simultaneous determination of these active components in H. cordata and H. cordata injection (HCI), including the intermediate product of HCI in productive process, from different pharmaceutical factories and different production batches, indicating that the method in this paper was particularly suitable for the routine analysis of HCI and its quality control in productive process.  相似文献   

6.
Headspace nanofiber sheet microextraction together with GC–MS and chemometrics resolution techniques were implemented to separate and identify the volatiles emitted by intact marjoram (Origanum majorana L.) and their relative concentrations. A novel polyaniline‐nylon‐6 nanofiber composite was applied for headspace microextraction. Characteristics such as high surface‐to‐volume ratio and π–π functional groups in polyaniline together with the NH and C=O functional groups in nylon‐6 make the polyaniline‐nylon‐6 nanofiber composite a suitable candidate for the extraction of volatiles and semivolatiles. The extracted constituents were desorbed and injected into the GC–MS system under the optimum conditions. Chemometric resolution techniques were utilized to solve the baseline offset, asymmetric peaks, and overlapped peaks problems that arise from GC–MS analysis. By means of these techniques and resolving the overlapped peak clusters, the number of identified constituents was increased to 67 compounds. The major released constituents from the intact marjoram leaves are 4‐terpineol, β‐linalool, cis‐sabinol, and trans‐geraniol.  相似文献   

7.
Systematic comparative research was conducted on essential oils from eight traditional Chinese medicines (TCM) of pungent flavor and cool nature because the essential oils are the main active ingredients of herbs of this kind. The work was based on their component analysis by gas chromatography–mass spectrometry (GC–MS), on their retention indices, as well as on chemometric resolution methods. A total of 144 compounds were tentatively identified, accounting for 69.0% to 91.8% of the total essential oils. It is worth noting that there are 67 compounds in at least three of these eight essential oils. Moreover, many biologically active compounds, such as hexanal, α‐pinene, camphene, β‐pinene, p‐cymene, limonene, eucalyptol, (Z)‐ocimene, γ‐terpinene, camphor, p‐menthone, 4‐terpineol, α‐terpineol, carvone, eugenol, caryophyllene, β‐farnesene, α‐curcumene, β‐selinene, δ‐cadinene, caryophyllene oxide, cedrol, n‐hexadecanoic acid, benzaldehyde, benzeneacetaldehyde, phthalic acid diisobutyl ester, linoleic acid, tetradecanoic acid, (Z,Z,Z)‐9,12,15‐octadecatrienoic acid, eucalyptol, pentadecanoic acid, hexadecanoic acid methyl ester, linoleic acid methyl ester, exist in at least four of the eight essential oils. These results might help us to understand why the eight herbs are all of pungent flavor and cool nature according to the theory of TCM, and may provide a useful chemical basis for future research on herbs of this kind.  相似文献   

8.
《Analytical letters》2012,45(4):630-639
In this work a simple and sensitive analytical method was developed for the determination of terpenoids in plants using gas chromatography coupled to mass spectrometry (GC-MS). Three extraction methods were tested on Ocimum basilicum leaves to maximize terpene extraction: Steam Distillation, Ultrasound-Assisted Extraction, and Microwave-Assisted Extraction (MAE). Best results, both in number of identified compounds and in their concentration, were obtained with MAE, which was used in all subsequent analyses. In particular five terpenoids (α-pinene, β-pinene, limonene, linalool, and α-terpineol) were chosen for the quantitative determination, performed in Selected Ion Monitoring mode. Calibration curves using dodecane as internal standard were drawn, showing good correlation coefficients (0.9981–0.9993). All figures of merit were satisfactory; limits of detection were in the range 14–27 ng for all analytes. The method was also applied to some specimens of wild-type and transgenic (GR and rolC) Nicotiana langsdorffii. Plants were exposed to water and chemical stresses to evaluate possible effects on terpene content. Linalool was present in higher quantities in the plants GR and rolC; both stresses produce a decrease of its concentration if compared to the non-stressed plants. The concentration of α-terpineol, detected only in WT and GR plants, was higher for the genetically modified plant, substantially confirming the trend observed for linalool.  相似文献   

9.
A novel poly(3,4-ethylenedioxythiophene)-ionic liquid (i.e., 1-hydroxyethyl-3-methyl imidazolium-bis[(trifluoromethyl)sulfonyl]imide) composite film was electrodeposited on a Pt wire for headspace solid-phase microextraction. The film showed nodular structure and had large specific surface. In addition, it displayed high thermal stability (up to 300 °C) and durable property (could be used for more than 200 times). Coupled with gas chromatography-flame ionization detection, the resulting fiber was applied to the headspace solid-phase microextraction and determination of several alcohols (i.e., linalool, nonanol, terpineol, geraniol, decanol and dodecanol). It presented higher extraction capability in comparison with the poly(3,4-ethylenedioxythiophene) and commercial polydimethylsiloxane/divinylbenzene fiber. Under the optimized conditions, the linear ranges exceeded three magnitudes with correlation coefficients above 0.9952 and the low limits of detection were 34.2–81.3 ng L−1. For different alcohols the repeatabilities (defined as RSD) were <5.8% and <7.8% for single fiber (n = 5) and fiber-to-fiber (n = 4), respectively. The proposed method was applied to the determination of these alcohols in real samples with acceptable recoveries from 81.1% to 106.6%.  相似文献   

10.
The essential oil, methanolic and aqueous extracts of the leaves and rhizomes of Hedychium coronarium Koen. (Zingiberaceae) were assayed for their antimicrobial, mosquito larvicidal and antioxidant properties. The chemical composition of the essential oil of two organs was analyzed by GC/MS analysis. β‐Pinene (33.9%), α‐pinene (14.7%), 1,8‐cineole (13.3%), r‐elemene (11.0%) and carotol (9.1%) were the main components in the leaf oil, including 82.0% terpenoid compounds. The major constituents of the rhizome oil were 1,8‐cineole (37.3%), β‐pinene (23.0%), α‐terpineol (10.4%) and α‐pinene (9.9%), comprising 80.6% of the oil. The leaf and rhizome essential oil displayed significant antimicrobial activity, as determined by the disc‐diffusion method, inhibiting the growth of all five fungal and four bacterial strains tested. The antimicrobial nature of the essential oil is related to high terpenoid contents. The leaf oil exhibited the mosquito larvicidal activity with 2 h and 24 h LC50 values of 111 and 90 ppm, respectively, while the rhizome oil showed the larvicidal activity with 2 h and 24 h LC50 values of 86 and 47 ppm, respectively. β‐Pinene, α‐pinene and 1,8‐cineol in H. coronarium serve as the principal larvicidal components of both oils. The individual antioxidant assays such as DPPH scavenging activity, chelating effect of ferrous ions and reducing power have been used. The present study demonstrated that the polar extracts of H. coronarium possessed anti‐oxidant. Appreciable total phenolic content (18.5‐26.3 mg/g) was also detected by Folin‐Ciocalteu test.  相似文献   

11.
A solid‐phase microextraction fiber was prepared by coating an optical fiber with a temperature‐sensitive polymer to determine phthalate esters. N‐Isopropylacrylamide and N,N′‐methylenebisacrylamide were used as the monomer and the cross linker, respectively. The fabricated fiber was characterized by FTIR spectroscopy, thermogravimetric analysis, and scanning electron microscopy. During extraction, important factors such as extraction time, pH, temperature, and ionic strength were optimized. The fabricated fiber, which is firm, inexpensive, stable, and efficient, is a vital material used in solid‐phase microextraction. Under optimum conditions, the calibration curve was linear and in the range of 1–20 μg/L (r2 = 0.9747). The high extraction efficiency was obtained for phthalates with a detection limit of 0.12 μg/L. The fabricated fiber was successfully applied to the solid‐phase micro extraction of phthalates from water samples after its extraction, followed by gas chromatography with flame ionization detection.  相似文献   

12.
In this study the investigation of the aroma compounds of dried fruits of Evodia rutaecarpa (Juss.) Benth. and E. rutaecarpa (Juss.) Benth. var. officinalis (Dode) Huang (i.e. E. officinalis Dode) (Rutaceae family) was carried out to identify the odorous target components responsible for the characteristic aroma of these valuable natural products. To avoid the traditional and more time-consuming hydrodistillation, the analyses were carried out by means of headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry (GC-MS). The SPME headspace volatiles were collected using a divinylbenzene-carboxen-polydimethylsiloxane (DVB-CAR-PDMS) fiber. The extraction conditions were optimized using a response surface experimental design to analyze the effect of three factors: extraction temperature, equilibrium time and extraction time. The best response was obtained when the extraction temperature was around 80 degrees C, equilibrium time near 25 min and extraction time close to 18 min. Analyses were performed by GC-MS with a 5% diphenyl-95% dimethyl polysiloxane (30 m x 0.25 mm I.D., film thickness 0.25 microm) capillary column using He as the carrier gas and a programmed temperature run. The main components of the HS-SPME samples of E. rutaecarpa (concentration >3.0%) were limonene (33.79%), beta-elemene (10.78%), linalool (8.15%), myrcene (5.83%), valencene (4.73%), beta-caryophyllene (4.62%), linalyl acetate (4.13%) and alpha-terpineol (3.99%). As for E. officinalis, the major compounds were myrcene (32.79%), limonene (18.36%), beta-caryophyllene (9.92%), trans-beta-ocimene (6.04%), linalool (5.88%), beta-elemene (7.85%) and valencene (4.62%).  相似文献   

13.
In this study, a new covalent organic framework, consisting of tetra(4‐aminophenyl)porphyrin and tris(4‐formyl phenyl)amine, was layer‐by‐layer immobilized on stainless‐steel wire as a coating for microextraction. The fabrication process was easy and controllable under mild conditions. The as‐grown fiber was applied to extract polycyclic aromatic hydrocarbons in aqueous solution via head‐space solid‐phase microextraction. Furthermore, it was analyzed by gas chromatography with a flame ionization detector. A wide linear range (0.1–50 µg/L), low limits of detection (0.006–0.024 µg/L, signal‐to‐noise ratio = 3), good repeatability (intra‐fiber, n = 6, 3.1–8.50%), and reproducibility (fiber to fiber; n = 3, 5.79–9.98%), expressed as relative standard deviations, demonstrate the applicability of the newly developed coating. This new material was successfully utilized in real sample extraction with a satisfactory result. Potential parameters affecting the extraction efficiency, including extraction temperature and extraction time, salt concentration, agitation speed, sample volume, desorption temperature, and time, were also optimized and discussed.  相似文献   

14.
Dispersive liquid–liquid microextraction (DLLME) coupled with gas chromatography–mass spectrometry (GC–MS) was applied for the determination of Rose water constituents. The effective parameters such as volume of extraction and disperser solvents, temperature, and salt effect were inspected by a full factorial design to identify important parameters and their interactions. It showed that salt addition had no effect on the efficiency. Next, a central composite design was applied to obtain optimum point of the important parameters. The optimal condition was obtained as 37.0 μL for extractor, 0.42 mL for disperser and temperature for 48 °C. The main components that were extracted at the optimum point were benzeneethanol (24.87%), geraniol (23.07%), beta-citronellol (22.38%), nerol (8.48%), eugenol (5.98%) and linalool (5.62%).  相似文献   

15.
Different compositions of monoterpenes are utilized for their pleasant scent in cosmetics and perfumes. However, the most commonly used fragrance terpenes easily oxidize upon contact with air, forming strongly skin‐sensitizing hydroperoxides. Due to their thermolability and low UV absorbance, detection methods for hydroperoxides are scarce. For the first time, a simple and sensitive method using LC/ESI‐MS/MS was developed to quantitatively determine hydroperoxides from the common fragrance compounds linalool, linalyl acetate, and limonene. The method was applied to autoxidized petitgrain oil and sweet orange oil. A separation was accomplished using a C3 column. The method LOD for the investigated hydroperoxides in the essential oils was below 0.3 μg/mL, corresponding to 0.3 ppm. For prevention purposes and according to EU regulations, concentrations in cosmetics exceeding 100 ppm in “rinse‐off” and 10 ppm in “stay‐on” products of linalool and limonene must be labeled. However, the products may still contain allergens, such as hydroperoxides, formed by oxidative degradation of their parent terpenes. The sensitivity and selectivity of the presented LC/MS/MS method enables detection of hydroperoxides from the fragrance terpenes linalool, linalyl acetate, and limonene. However, for routine measurements, the method requires further validation.  相似文献   

16.
A simple and sensitive analytical methodology is developed for rapid screening and quantification of selected estrogenic endocrine disrupting chemicals and bisphenol A from intact milk using fabric phase sorptive extraction in combination with high‐performance liquid chromatography coupled to ultraviolet detection/tandem mass spectrometry. The new approach eliminates protein precipitation and defatting step from the sample preparation workflow. In addition, the error prone and time‐consuming solvent evaporation and sample reconstitution step used as the sample post‐treatment has been eliminated. Parameters with most significant impact on the extraction efficiency of fabric phase sorptive extraction including sorbent chemistry, sample volume, extraction time have been thoroughly studied and optimized. Separation of the selected estrogenic endocrine disrupting chemicals including α‐estradiol, hexestrol, estrone, 17α‐ethinyl estradiol, diethylstilboestrol, and bisphenol A were achieved using a Zorbax Extend‐C18 high‐performance liquid chromatography column (15 cm × 4.6 mm, 5 μm particle size). The limit of detection values obtained in fabric phase sorptive extraction with high‐performance liquid chromatography with ultraviolet detection ranged from 25.0 to 50.0 ng/mL. The method repeatability values were 3.6–13.9 (relative standard deviation, %) and intermediate precision values were 4.6–12.7 (relative standard deviation, %). The fabric phase sorptive extraction method was also coupled to liquid chromatography with tandem mass spectrometry for identifying each endocrine disrupting chemical at 10 ng/mL.  相似文献   

17.
The reversed‐phase mode of single drop microextraction has been used as a preparation method for the extraction of some phenolic antioxidants from edible oil samples. Butylated hydroxyl anisole, tert‐butylhydroquinone and butylated hydroxytoluene were employed as target compounds for this study. High‐performance liquid chromatography followed by fluorescence detection was applied for final determination of target compounds. The most interesting feature of this study is the application of a disposable insulin syringe with some modification for microextraction procedure that efficiently improved the volume and stability of the solvent microdrop. Different parameters such as the type and volume of solvent, sample stirring rate, extraction temperature, and time were investigated and optimized. Analytical performances of the method were evaluated under optimized conditions. Under the optimal conditions, relative standard deviations were between 4.4 and 10.2%. Linear dynamic ranges were 20–10 000 to 2–1000 μg/g (depending on the analytes). Detection limits were 5–670 ng/g. Finally, the proposed method was successfully used for quantification of the antioxidants in some edible oil samples prepared from market. Relative recoveries were achieved from 88 to 111%. The proposed method had a simplicity of operation, low cost, and successful application for real samples.  相似文献   

18.
A solid‐phase microextraction with carbon nanospheres coated fiber coupled with gas chromatographic detection was established for the determination of eight polycyclic aromatic hydrocarbons (naphthalene, biphenyl, acenaphthene, fluorine, phenanthrene, anthracene, fluoranthene, and pyrene) in water and soil samples. The experimental parameters (extraction temperature, extraction time, stirring rate, headspace volume, salt content, and desorption temperature) which affect the extraction efficiency were studied. Under the optimized conditions, good linearity between the peak areas and the concentrations of the analytes was achieved in the concentration range of 0.5‐300 ng/mL for water samples, and in the concentration range of 6.0‐2700 ng/g for soil samples. The detection limits for the analytes were in the range of 0.12‐0.45 ng/mL for water samples, and in the range of 1.53‐2.70 ng/g for soil samples. The method recoveries of the polycyclic aromatic hydrocarbons for spiked water samples were 80.10‐120.1% with relative standard deviations less than 13.9%. The method recoveries of the analytes for spiked soil samples were 80.40‐119.6% with relative standard deviations less than 14.4%. The fiber was reused over 100 times without a significant loss of extraction efficiency.  相似文献   

19.
A novel graphene/dodecanol floating solidification microextraction followed by HPLC with diode‐array detection has been developed to extract trace levels of four cinnamic acid derivatives in traditional Chinese medicines. Several parameters affecting the performance were investigated and optimized. Also, possible microextraction mechanism was analyzed and discussed. Under the optimum conditions (amount of graphene in dodecanol: 0.25 mg/mL; volume of extraction phase: 70 μL; pH of sample phase: 3; extraction time: 30 min; stirring rate: 1000 rpm; salt amount: 26.5% NaCl; volume of sample phase: 10 mL, and without dispersant addition), the enrichment factors of four cinnamic acid derivatives ranged from 26 to 112, the linear ranges were 1.0 × 10−2–10.0 μg/mL for caffeic acid, 1.3 × 10−3–1.9 μg/mL for p‐hydroxycinnamic acid, 2.8 × 10−3–4.1 μg/mL for ferulic acid, and 2.7 × 10−3–4.1 μg/mL for cinnamic acid, with r 2 ≥ 0.9993. The detection limits were found to be in the range of 0.1–1.0 ng/mL, and satisfactory recoveries (92.5–111.2%) and precisions (RSDs 1.1–9.5%) were also achieved. The results showed that the approach is simple, effective and sensitive for the preconcentration and determination of trace levels of cinnamic acid derivatives in Chinese medicines. The proposed method was compared with conventional dodecanol floating solidification microextraction and other extraction methods.  相似文献   

20.
A simple and rapid method using microextraction by packed sorbent coupled with gas chromatography and mass spectrometry has been developed for the analysis of five phthalates, namely, diethyl phthalate, benzyl‐n‐butyl phthalate, dicyclohexyl phthalate, di‐n‐butyl phthalate, and di‐n‐propyl phthalate, in cold drink and cosmetic samples. The various parameters that influence the microextraction by packed sorbent performance such as extraction cycle (extract–discard), type and amount of solvent, washing solvent, and pH have been studied. The optimal conditions of microextraction using C18 as the packed sorbent were 15 extraction cycles with water as washing solvent and 3 × 10 μL of ethyl acetate as the eluting solvent. Chromatographic separation was also optimized for injection temperature, flow rate, ion source, interface temperature, column temperature gradient and mass spectrometry was evaluated using the scan and selected ion monitoring data acquisition mode. Satisfactory results were obtained in terms of linearity with R2 >0.9992 within the established concentration range. The limit of detection was 0.003–0.015 ng/mL, and the limit of quantification was 0.009–0.049 ng/mL. The recoveries were in the range of 92.35–98.90% for cold drink, 88.23–169.20% for perfume, and 88.90–184.40% for cream. Analysis by microextraction by packed sorbent promises to be a rapid method for the determination of these phthalates in cold drink and cosmetic samples, reducing the amount of sample, solvent, time and cost.  相似文献   

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