Rapid determination of floral aroma compounds of lilac blossom by fast gas chromatography combined with surface acoustic wave sensor

A novel analytical method using fast gas chromatography combined with surface acoustic wave sensor (GC/SAW) has been developed for the detection of volatile aroma compounds emanated from lilac blossom (Syringa species: Syringa vulgaris variginata and Syringa dilatata). GC/SAW could detect and quantify various fragrance emitted from lilac blossom, enabling to provide fragrance pattern analysis results. The fragrance pattern analysis could easily characterize the delicate differences in aromas caused by the substantial difference of chemical composition according to different color and shape of petals. Moreover, the method validation of GC/SAW was performed for the purpose of volatile floral actual aroma analysis, achieving a high reproducibility and excellent sensitivity. From the validation results, GC/SAW could serve as an alternative analytical technique for the analysis of volatile floral actual aroma of lilac. In addition, headspace solid-phase microextraction (HS-SPME) GC-MS was employed to further confirm the identification of fragrances emitted from lilac blossom and compared to GC/SAW.     

Application of HS-SPME and GC-MS to characterization of volatile compounds emitted from Osmanthus flowers

Headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) was developed for characterization of volatile compounds emitted from two varieties Osmanthus flowers of O. fragrans var. latifolius and O. fragrans var. thunbergii. The SPME parameters were studied, the optimum conditions of a 65 microm carbowax/divinylbenzene (CW/DVB), extraction temperature of 22 degrees C and extraction time of 10 min were obtained and applied to extraction of the volatile emissions. Fourteen compounds released from both varieties of Osmanthus flowers were separated and identified by GC-MS, which mainly included alpha-linalool, beta-linalool, trans-linalool oxide, cis-linalool oxide, alpha-lonone, beta-lonone, capraldehyde and decalactone. By comparing their peak areas, we found that the sums of the fourteen compounds from the two Osmanthus flowers were very close, while the relative contents of individual volatile compounds in the two emissions were very different. The relative content of alpha-linalool and beta-linalool in O. fragrans var. latifolius were 39.46% and 0.51%, while in O. fragrans var. thunbergii were 9.53% and 27.71%. Due to their different relative contents, the two varieties of flower have different fragrances.     

Headspace solid-phase microextraction for characterization of fragrances of lemon verbena (Aloysia triphylla) by gas chromatography-mass spectrometry

Natural fragrances from lemon verbena (Aloysia triphylla) were studied by headspace solid phase microextraction (HS-SPME) techniques followed by gas chromatography-mass spectrometry (GC-MS), with six different fibre coatings being tested to evaluate the extraction efficiencies of several selected compounds. A total of 14 compounds were identified in the fragrances of lemon verbena. Geranial and neral were detected as major components and alpha-pinene, beta-pinene, beta-caryophyllene, and curcumene as minor components. Enantiomeric analysis of chiral compounds from lemon verbena was carried out on a chiral column. alpha-Pinene, limonene, and camphor in the fragrances emitted from lemon verbena were found in the (+), (-), and (-) forms, respectively.     

Headspace solid-phase microextraction analysis of aroma compounds in vinegar. Validation study

Headspace solid-phase microextraction (HS-SPME) was evaluated for analysing aromatic compounds in vinegar. The fibre used (a Carboxen-polydimethylsiloxane fibre), and the analytical conditions had been optimised in a previous work. The HS-SPME procedure developed shows detection and quantitation limits, and linear ranges adequate for analysing this type of compounds. The recoveries obtained were close to 100%, with repeatability values lower than 20%. However, considerable differences have been detected between different fibres. The method was applied to a variety of Sherry wine vinegars.     

Gas chromatography-mass spectrometry following pressurized hot water extraction and solid-phase microextraction for quantification of eucalyptol, camphor, and borneol in Chrysanthemum flowers

Chrysanthemum flower is a common traditional Chinese medicine (TCM). In this work, pressurized hot water extraction (PHWE) followed by headspace solid-phase microextraction (HS-SPME) and GC-MS was developed for the determination of three main active volatile compounds of eucalyptol, camphor, and borneol in Chrysanthemum flowers from four different growing areas in China by internal standard method. The parameters of PHWE and HS-SPME were optimized. The method was also validated. The results showed that PHWE-SPME-GC-MS is a simple, rapid, efficient, and solvent-free technique for the quantitative determination of eucalyptol, camphor, and borneol in TCMs and is potentially useful for the TCM quality assessment.     

Comparison of different extraction methods for the analysis of fragrances from Lavandula species by gas chromatography-mass spectrometry

Various sampling techniques including solid-phase trapping solvent extraction (SPTE), headspace solid-phase microextraction (HS-SPME), reduced pressure steam distillation (RPSD) and simultaneous steam distillation-solvent extraction (SDE) were compared for the gas chromatography-mass spectrometry of the fragrances from the Lavandula species. Linalyl acetate (35.44%) and linalool (18.70%) were predominant components of Hidcote lavender samples obtained by SPTE whereas those levels were 2.63-4.04 and 36.80-43.47% in the same samples by RPSD and SDE, respectively. The partition coefficients between the headspace gaseous phase and HS-SPME fiber, and the relative concentration factors of the four characteristic components of the lavender were measured for relative evaluation of the fiber efficiency. Five different coatings were evaluated and 100-microm poly(dimethylsiloxane) was the most efficient for the successful extraction of lavender fragrances. A total of 43 compounds were identified by SPTE and gas chromatography-mass spectrometry from four Lavandula species. Lavandula angustifolia Hidcote species, which contains a higher level of linalyl acetate and linalool but little camphor, was evaluated as the highest quality among the four different Lavandula species.     

Analysis of odorous trichlorobromophenols in water by in-sample derivatization/solid-phase microextraction GC/MS

The simultaneous determination of several odorous trichlorobromophenols in water has been carried out by an in-sample derivatization headspace solid-phase microextraction method (HS-SPME).The analytical procedure involved their derivatization to methyl ethers with dimethyl sulfate/NaOH and further HS-SPME and gas chromatography-mass spectrometry (GC/MS) determination. Parameters affecting both the derivatization efficiency and headspace SPME procedures, such as the selection of the SPME fiber coating, derivatization–extraction time and temperature, were studied. The commercially available polydimethylsiloxane (PDMS) 100 μm and Carboxen-polydimethylsiloxane-divinylbenzene (CAR-PDMS-DVB) fibers appeared to be the most suitable for the simultaneous determination of these compounds. The precision of the HS-SPME/GC/MS method gave good relative standard deviations (RSDs) run-to-run between 9% and 19% for most of them, except for 2,5-diCl-6-Br-phenol, 2,6-diCl-3-Br-phenol and-2,3,6-triBr-phenol (22%, 25% and 23%, respectively). The method was linear over two orders of magnitude, and detection limits were compound dependent but ranged from 0.22 ng/l to 0.95 ng/l. The results obtained for water samples using the proposed SPME procedure were compared with those found with the EPA 625 method, and good agreement was achieved. Therefore, the in-sample derivatization HS-SPME/GC/MS procedure here proposed is a suitable method for the simultaneous determination of odorous trichlorobromophenols in water.     

Fast quality assessment of German chamomile (Matricaria chamomilla L.) by headspace solid-phase microextraction: influence of flower development stage

For an adequate quality evaluation of aromatic plants grown under different conditions, a rapid, simple and sensitive method for the analysis of volatile constituents is indispensable. The main objective of the present study was to compare fast screening of German chamomile (Matricaria chamomilla L.) by means of headspace solid-phase microextraction (HS-SPME) with conventional isolation of the essential oil (steam distillation-solvent extraction (SDSE)) for the differentiation of chamomile essential oil constituents. Flowers were harvested at two distinct development stages: stage I, when ligulate flowers start to develop and tubular flowers are still closed, and stage II, when tubular flowers are partially to completely opened. Dried chamomile flowers at two development stages were extracted by means of both SDSE and HS-SPME, followed by GC-MS analysis. Among 30 compounds detected, (E)-beta-farnesene (49%), artemisia ketone (10%) and germacrene D (9%) were the predominant volatile components in the HS-SPME-extract, while alpha-bisabolol oxide A (42%), chamazulene (21%) and (Z)-spiroether (8%) were the main essential oil constituents among the 13 compounds obtained by SDSE. After statistical analysis of the data, both techniques enabled the same conclusion: (E)-beta-farnesene was the only compound which showed significant differences between the two flower development stages. These results suggest that HS-SPME-GC-MS can be used as a sensitive technique for the rapid screening and quality assessment of M. chamomilla.     

Use of solid-phase microextraction as a sampling technique for the characterization of volatile compounds emitted from Chinese daffodil flowers

Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) has been applied to the determination of volatile compounds emitted from living daffodil flowers. The SPME conditions were optimized and applied to headspace extraction of the volatile compounds. The volatile compounds adsorbed on the fiber were desorbed and analyzed by GC-MS. We identified 27 compounds in the flower emission, which mainly included acetic acid phenethyl ester (31.68%), E-ocimene (17.15%), acetic acid benzyl ester (11.53%), neo-allo-ocimene (6.94%), allo-ocimene(5.34%), α-linalool (5.26%), 1,8-cineole(3.70%), benzenepropyl acetate (1.98%), and 3-methyl-2-buten-1-ol acetate(1.88%). The volatile compounds emitted by the flower excised from the daffodil were also analyzed by the present method, and the results showed that n-pentadecane, n-hexadecane, n-octadecane, and acetic acid phenethyl ester might be biomarker compounds of living daffodil flowers. To our knowledge, this is the first report on the volatile compounds emitted from Chinese daffodil flowers. The text was submitted by the authors in English.     

The Sensitivity of Gas Chromatography-Headspace Solid Phase Microextraction in Relationship with Relative Volatility of Volatile Organic Compounds

In order to explore the analytical performance of Headspace-Solid-phase Microextraction (HS-SPME), the sensitivity of gas chromatography (GC)-Mass Spectrometry (MS) determinations was examined in terms of calibration slopes, that is, response factor values of selected volatile organic compounds (VOC). The HS-SPME was applied to extract two kinds of gaseous VOC analytes, namely group I (methyl ethyl ketone, isobutyl alcohol, methyl isobutyl ketone, and butyl acetate, all having high water solubility) and group II (benzene, toluene, styrene, and xylene, all having moderate water solubility) from water solutions. The results, derived by both external and internal calibration, were then evaluated by considering headspace sample volume and solute volatility. In the case of solutes consisting of group I, sensitivity seems to increase with increasing HS size, although there are no such discernible patterns for group II solutes. The observed relative patterns in extraction efficiency may be accounted for by the differences in intermolecular forces present between the compounds of groups I and II and the possible effects of diffusion kinetics of the VOCs to the SPME fiber or competitive adsorption between different VOCs. As such, sensitivity of HS-SPME is tightly affected by the air-water partitioning properties of the target compounds and the response of SPME to such properties.     

Determination of chlorinated volatile organic compounds in water and municipal wastewater using headspace-solid phase microextraction-gas chromatography

The aim of this work was to develop a fast and simple analytical method for the determination of 14 chlorinated volatile organic compounds (VOCs) in water and wastewater samples. Headspace-solid-phase microextraction (HS-SPME) and gas chromatography (GC) were used for the determination of the VOCs. The extraction parameters were investigated in order to optimize the HS-SPME-GC method. The quality parameters of the method were also investigated.     

Emission pattern of semi-volatile organic compounds from recycled styrenic polymers using headspace solid-phase microextraction gas chromatography–mass spectrometry

The emission of low molecular weight compounds from recycled high-impact polystyrene (HIPS) has been investigated using headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry (GC–MS). Four released target analytes (styrene, benzaldehyde, acetophenone, and 2-phenylpropanal) were selected for the optimisation of the HS-SPME sampling procedure, by analysing operating parameters such as type of SPME fibre (polarity and operating mechanism), particle size, extraction temperature and time. 26 different compounds were identified to be released at different temperatures from recycled HIPS, including residues of polymerisation, oxidated derivates of styrene, and additives. The type of SPME fibre employed in the sampling procedure affected the detection of emitted components. An adsorptive fibre such as carbowax/polydimethylsiloxane (CAR/PDMS fibre) offered good selectivity for both non-polar and polar volatile compounds at lower temperatures; higher temperatures result in interferences from less-volatile released compounds. An absorptive fibre as polydimethylsiloxane (PDMS) fibre is suitable for the detection of less-volatile non-polar molecules at higher temperatures. The nature and relative amount of the emitted compounds increased with higher exposure temperature and smaller polymeric particle size. HS-SPME proves to be a suitable technique for screening the emission of semi-volatile organic compounds (SVOCs) from polymeric materials; reliable quantification of the content of target analytes in recycled HIPS is however difficult due to the complex mass-transfer processes involved, matrix effects, and the difficulties in equilibrating the analytical system.     

Investigations on the emission of fragrance allergens from scented toys by means of headspace solid-phase microextraction gas chromatography–mass spectrometry

In the revised European toy safety directive 2009/48/EC the application of fragrance allergens in children's toys is restricted. The focus of the present work lies on the instrumental analytics of 13 banned fragrance allergens, as well as on 11 fragrance allergens that require declaration when concentrations surpass 100 μg per gram material. Applying a mixture of ethyl acetate and toluene solid/liquid extraction was performed prior to quantitative analysis of mass contents of fragrances in scented toys. In addition, an easy-to-perform method for the determination of emitted fragrances at 23 °C (handling conditions) or at 40 °C (worst case scenario) has been worked out to allow for the evaluation of potential risks originating from inhalation of these compounds during handling of or playing with toys. For this purpose a headspace solid-phase microextraction (HS-SPME) technique was developed and coupled to subsequent gas chromatography–mass spectrometry (GC–MS) analysis. Fragrance allergens were adsorbed (extracted) from the gas phase onto an 85 μm polyacrylate fiber while incubating pieces of the scented toys in sealed headspace vials at 23 °C and 40 °C. Quantification of compounds was performed via external calibration. The newly developed headspace method was subsequently applied to five perfumed toys. As expected, the emission of fragrance allergens from scented toys depends on the temperature and on the content of fragrance allergens present in those samples. In particular at conditions mimicking worst case (40 °C), fragrance allergens in toys may pose a risk to children since considerable amounts of compound might be absorbed by lung tissue via breathing of contaminated air.     

Estimation of dermal and oral exposure of children to scented toys: analysis of the migration of fragrance allergens by dynamic headspace GC-MS

Fragrances capable of inducing contact allergy in skin potentially can migrate from the toy to the child via oral or dermal contacts. The goal of this work was the developing of an analytical method based on dynamic headspace GC-MS to determine the concentration of 24 fragrances in saliva or sweat simulant. Under optimized conditions, 5 mL of the migration simulant with 2 g sodium chloride were incubated for 10 min at 30°C. The headspace was purged at a flow rate of 50 mL/min. The compounds were quantified by internal calibration resulting in good linearity (>0.991). The recovery was greater than 66.3% for most of the compounds. The limits of detection ranged between 0.5 ng/mL for hydrophobic and 196.0 ng/mL for hydrophilic fragrances. The method was subsequently applied to seven real toys purchased from the market. The highest migration rate could be observed for benzyl benzoate with 268.0 ng/cm(2)/min. Based on the migration data measured, the ranges of dermal and oral exposure of children to fragrances in scented toys were calculated. The maximum oral and dermal exposure levels were estimated at 22.2 μg per kg body weight (BW) and day (d) for benzyl benzoate and 605.0 μg/kg BW/d for benzyl alcohol, respectively.     

Development of pressurized hot water extraction followed by headspace solid-phase microextraction and gas chromatography-mass spectrometry for determination of ligustilides in Ligusticum chuanxiong and Angelica sinensis

In this work, a simple, rapid, solvent-free, and low-cost method was developed for the determination of ligustilides in traditional Chinese medicines (TCMs), which was based on pressurized hot water extraction (PHWE) followed by headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). The two bioactive compounds Z-ligustilide and E-ligustilide in two common TCMs, viz. Ligusticum chuanxiong and Angelica sinensis, were extracted by water at 150 degrees C and 40 bar, followed by concentration with HS-SPME and detection by GC-MS. PHWE and HS-SPME parameters were investigated and method validation (precision and recovery) was studied. It has been shown that the proposed method provides a powerful approach for quantitative analysis of ligustilides in TCMs. The method was applied to determination of ligustildes in the TCMs from different growing areas. The results indicate that PHWE-HS-SPME-GC-MS is a potential tool for TCM quality assessment.     

Comparison of two extraction methods for evaluation of volatile constituents patterns in commercial whiskeys Elucidation of the main odour-active compounds

An analytical procedure based on manual dynamic headspace solid-phase microextraction (HS-SPME) method and the conventional extraction method by liquid-liquid extraction (LLE), were compared for their effectiveness in the extraction and quantification of volatile compounds from commercial whiskey samples. Seven extraction solvents covering a wide range of polarities and two SPME fibres coatings, has been evaluated. The highest amounts extracted, were achieved using dichloromethane (CH₂Cl₂) by LLE method (LLECH₂Cl₂) and using a CAR/PDMS fibre (SPME_CAR/PDMS) in HS-SPME. Each method was used to determine the responses of 25 analytes from whiskeys and calibration standards, in order to provide sensitivity comparisons between the two methods. Calibration curves were established in a synthetic whiskey and linear correlation coefficient (r) were greater than 0.9929 for LLECH₂Cl₂ and 0.9935 for SPME_CAR/PDMS, for all target compounds. Recoveries greater than 80% were achieved. For most compounds, precision (expressed by relative standard deviation, R.S.D.) are very good, with R.S.D. values lower than 14.78% for HS-SPME method and than 19.42% for LLE method. The detection limits ranged from 0.13 to 19.03 μg L⁻¹ for SPME procedure and from 0.50 to 12.48 μg L⁻¹ for LLE.A tentative study to estimate the contribution of a specific compound to the aroma of a whiskey, on the basis of their odour activity values (OAV) was made. Ethyl octanoate followed by isoamyl acetate and isobutyl alcohol, were found the most potent odour-active compounds.     

Comparative analysis of volatile compounds of ‘fino’ sherry wine by rotatory and continuous liquid-liquid extraction and solid-phase microextraction in conjunction with gas chromatography-mass spectrometry

Different headspace solid-phase microextraction (HS-SPME) methods have been selected and applied to the analysis of volatile compounds in ‘fino’ sherry wine by gas chromatography-mass spectrometry. A method based on rotary and continuous liquid-liquid extraction (LLE) for analysis of these same compounds has been optimised. The best conditions to extract this type of compounds using SPME and LLE were determined and both methods were validated. Both methodologies show adequate detection and quantitation limits, and linear ranges for correctly analysing these compounds. The recoveries obtained were close to 100%, with good repeatability values. The analytical and procedural advantages and disadvantages of these two methods have been compared. In general, SPME presented higher sensitivities. Both analytical methods were used to analyse five samples of ‘fino’ sherry wine supplied by different producers. No significant differences were found between the techniques at a significance level of 5%. The regression coefficients (r²) for analysis using LLE and SPME exceeded 0.94 for all compounds. The LLE procedure is a method with high repeatability and has the possibility of simultaneous extraction of several samples (up to 12), however the SPME technique is a solvent-free method presenting major advantages, such as small sample volume and higher sensitivity and simplicity.     

An automated headspace solid-phase microextraction followed by gas chromatography–mass spectrometry method to determine macrocyclic musk fragrances in wastewater samples

A fully automated method has been developed for determining eight macrocyclic musk fragrances in wastewater samples. The method is based on headspace solid-phase microextraction (HS-SPME) followed by gas chromatography–mass spectrometry (GC-MS). Five different fibres (PDMS 7 μm, PDMS 30 μm, PDMS 100 μm, PDMS/DVB 65 μm and PA 85 μm) were tested. The best conditions were achieved when a PDMS/DVB 65 μm fibre was exposed for 45 min in the headspace of 10 mL water samples at 100 °C. Method detection limits were found in the low ng L^?1 range between 0.75 and 5 ng L^?1 depending on the target analytes. Moreover, under optimized conditions, the method gave good levels of intra-day and inter-day repeatabilities in wastewater samples with relative standard deviations (n?=?5, 1,000 ng L^?1) less than 9 and 14 %, respectively. The applicability of the method was tested with influent and effluent urban wastewater samples from different wastewater treatment plants (WWTPs). The analysis of influent urban wastewater revealed the presence of most of the target macrocyclic musks with, most notably, the maximum concentration of ambrettolide being obtained in WWTP A (4.36 μg L^?1) and WWTP B (12.29 μg L^?1), respectively. The analysis of effluent urban wastewater showed a decrease in target analyte concentrations, with exaltone and ambrettolide being the most abundant compounds with concentrations varying between below method quantification limit (<MQL) and 2.46 μg L^?1.

Determination of Tetrachloroethylene and Other Volatile Halogenated Organic Compounds in Oil Wastes by Headspace SPME GC–MS

Oil wastes and slops are complex mixtures of hydrocarbons, which may contain a variety of contaminants including tetrachloroethylene (perchloroethylene, PCE) and other volatile halogenated organic compounds (VHOCs). The analytical determination of PCE at trace levels in petroleum-derived matrices is difficult to carry out in the presence of large amounts of hydrocarbon matrix components. In the following study, we demonstrate that headspace solid-phase microextraction (HS-SPME) combined with GC–MS analysis can be applied for the rapid measurement of PCE concentration in oil samples. The HS-SPME method was developed using liquid paraffin as matrix matching reference material for external and internal calibration and optimisation of experimental parameters. The limit of quantitation was 0.05 mg kg⁻¹, and linearity was established up to 25 mg kg⁻¹. The HS-SPME method was extended to several VHOCs, including trichloroethylene (TCE) in different matrices and was applied to the quantitative analysis of PCE and TCE in real samples.     

Synthetic musk fragrances in environmental Standard Reference Materials

Synthetic musk fragrances have been measured in water, air, sediments, sewage sludge, and biota worldwide. As the study of the environmental fate and impacts of these compounds progresses, the need for Standard Reference Materials (SRMs) for these compounds to facilitate analytical method improvement and interlaboratory comparisons becomes increasingly important. The National Institute of Standards and Technology (NIST) issues environmental matrix SRMs with certified concentrations for a variety of persistent organic pollutants including polycyclic aromatic hydrocarbons (PAHs), chlorinated pesticides, and polychlorinated biphenyl congeners (PCBs). Until now synthetic musk fragrance concentrations have not been reported in NIST SRMs. The objective of this study was to provide reference values for several commonly detected synthetic musk fragrances in several NIST natural matrix SRMs. In this study five polycyclic musk fragrances [HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-γ-2-benzopyran), AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene), ADBI (4-acetyl-1,1-dimethyl-6-tert-butylindane), AHMI (6-acetyl-1,1,2,3,3,5-hexamethylindane), and ATII (5-acetyl-1,1,2,6-tetramethyl-3-isopropylindane] and two nitro musk fragrances [musk xylene (1-tert-butyl-3,5-dimethyl-2,4,6-trinitrobenzene) and musk ketone (4-tert-butyl-3,5-dinitro-2,6-dimethylacetophenone)] were measured in selected environmental SRMs. Gas chromatography–electron impact mass spectrometry (GC/EI-MS) was used for all analyses. HHCB was the most frequently detected synthetic musk fragrance and was detected in SRM 2585 Organic Contaminants in House Dust, SRM 2781 Domestic Sludge, SRM 1974b Organics in Mussel Tissue (Mytilus edulis), and SRM 1947 Lake Michigan Fish Tissue. It was not detected in SRM 1946 Lake Superior Fish Tissue or SRM 1945 Organics in Whale Blubber. Concentrations of HHCB in these SRMs ranged from 1.12 ng/g in SRM 1947 to 92,901 ng/g in SRM 2781. All of the polycyclic musk fragrances were detected in SRM 2781 and all of the target compounds were detected in SRM 2585. Electronic supplementary material Supplementary material is available for this article at and is accessible to authorized users.