Application Of Headspace Solid-phase Microextraction Research Articles

Comprehensive Two-Dimensional Gas Chromatography-Mass Spectrometry as a Tool for the Untargeted Study of Hop and Their Metabolites.

Since hop secondary metabolites have a direct correlation with the quality of beer and other hop-based beverages, and the volatile fraction of hop has a complex composition, requiring effective separation, here we explore the application of headspace solid-phase microextraction as a sample preparation method, coupled with comprehensive two-dimensional gas chromatography-mass spectrometry (GC×GC-MS) analysis. The methodology involved the use of a DVB/PDMS fibre with 500 mg of hop cone powder, extracted for 40 min at 50 °C, for both GC-MS and GC×GC-MS. The varieties Azacca, Cascade, Enigma, Loral, and Zappa were studied comprehensively. The results demonstrate that GC×GC-MS increases the number of peaks by over 300% compared to classical GC-MS. Overall, 137 compounds were identified or tentatively identified and categorised into 10 classes, representing between 87.6% and 96.9% of the total peak area. The composition revealed the highest concentration of sesquiterpene hydrocarbons for Enigma, whilst Zappa showed a relatively significant concentration of monoterpene hydrocarbons. Principal component analysis for all compounds and classes, along with hierarchical cluster analysis, indicated similarities between Zappa and Cascade, and Azacca and Loral. In conclusion, this method presents an optimistic advancement in hop metabolite studies with a simple and established sample preparation procedure in combination with an effective separation technique.

Battery-Operated and Self-Heating Solid-Phase Microextraction Device for Field Detection and Long-Term Preservation of Mercury in Soil.

The application of headspace solid-phase microextraction (HS-SPME) for mercury preservation and detection still has several shortcomings, including the use of high-temperature desorption chamber, the consumption of expensive reagent (NaBEt4 or NaBPr4), and analyte loss during sample storage. Herein, a self-heating HS-SPME device using a gold-coated tungsten (Au@W) fiber was developed for the field detection of mercury in soil by miniature point discharge optical emission spectrometry (μPD-OES). Hg2+ was reduced to Hg0 with NaBH4 solution and then preconcentrated with the Au@W fiber. The adsorbed Hg0 could be rapidly desorbed by directly heating the fiber with a mini lithium battery and subsequently detected by μPD-OES. A limit of detection (LOD) of 0.008 mg kg-1 was obtained with a relative standard deviation (RSD) of 2.4%. The accuracy of the self-heating HS-SPME was evaluated by analyzing a soil certified reference material (CRM) and nine soil samples with satisfactory recoveries (86-111%). Compared to the conventional external heating method, the proposed method reduces desorption time and power consumption from 80 s and 60 W to 20 s and 2.5 W, respectively. Moreover, the self-heating device enables the μPD-OES system to remove the high-temperature desorption chamber, making it more compact and suitable for field analytical chemistry. Interestingly, the Au@W SPME fiber can be also used for the long-term preservation of mercury with a sample loss rate <5% after 30 days of storage at room temperature.

Applications of headspace solid-phase microextraction in human biological matrix analysis

Abstract The inherent complexity of the human biological matrix and its importance in modern medical diagnosis and medical research promote the development of modern analytical technology. Solid-phase microextraction technology has been widely used in the treatment and analysis of different complex biological matrices due to its smaller sample size, simpler sample preparation and setting, and lower consumption of harmful chemicals. This review provides updated information on headspace solid-phase microextraction combined with gas chromatography technique applications, focusing on the analysis of volatile and semivolatile compounds in human biological matrices. The application of headspace solid-phase microextraction combined with gas chromatography techniques in human biological matrix analysis is mainly summarized into three aspects, namely, to discover biomarkers, to investigate volatile metabolomics, and to explore the effect of the external environment on volatile metabolomics of the human biological matrix. In addition, the frequently used statistical analytical methods are summarized, and the application prospect of solid-phase microextraction in the analysis of human biological matrices is proposed.

INNOVATIVE GAS CHROMATOGRAPHIC DETERMINATION OF FORMALDEHYDE BY MINIATURIZED EXTRACTION AND ON-FIBER DERIVATIZATION, VIA SPME AND SPME ARROW

Formaldehyde (FA) is a carbonyl compound, ubiquitous in the environment and among the most widespread pollutants: it has exhibited toxic properties and is classified as a human carcinogen. FA is released from several sources, both temporary (e.g., combustion processes) and permanent (e.g., building products). This work proposes an innovative fully-automated application of headspace solid-phase microextraction (SPME) with on-fiber derivatization for the analysis of airborne FA emitted from liquid solutions or solid manufacts, in static mode, via gas chromatography-mass spectrometry. The method was tested in a wide range of airborne FA concentrations, using SPME and SPME Arrow fibers: the inter-day LOD and LOQ for SPME and SPME Arrow were evaluated, resulting in 0.072 and 0.215 ppm and 0.014 and 0.042 ppm, respectively. Moreover, other conventional detectors, such as Electron Capture Detector (ECD), Thermoionic Specific Detector (TSD), Photoionization Detector (PID), and Flame Ionization Detector (FID), were tested to set an analytical method to meet different requirements. The sensitivity and linearity of PID, FID and MS were comparable, while TSD and ECD were not suitable for the developed method, due to issues of response or linearity. MS results to be the most suitable and perfoming detector, however PID and FID result to be cheaper valid alternatives.

Kinetin establish the volatile chemical profile after rhizome dormancy is released in Curcuma zedoaria (Christm.) Roscoe

The aim of this work was to provide information about kinetin effects on chemical volatile profile of Curcuma zedoaria (Christm.) Roscoe after several days of plant dormancy release. Rhizomes of C. zedoaria were immersed in four kinetin concentrations (0, 50, 100, 150 mg ml−1, n = 12 by each concentration) for 30 min. After 240 h of treatment, root length (mm), bud break (%) and bud speed index (BSI) were measured, and three rhizomes at 24 h and 240 h were collected for chemical volatile profile analysis by application of headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography–mass spectrometry (GC–MS). Kinetin does not alter morphological aspects of the bud dormancy releasing, but drastically changes metabolic aspects of volatile production on C. zedoaria rhizomes, by the selection of several monoterpenes, such as camphene, sabinene, isoborneol, borneol, 1,8-cineole. We assume that kinetin application maintain monoterpene production as a consequence of its signaling over dormancy release.

The Application of Headspace Solid-phase Microextraction as a Preparation Approach for Gas Chromatography with Mass Spectrometry

Reviewed in brief are the selected results of the application of headspace solid-phase microextraction as a preparative approach for gas chromatography – mass spectrometry (HS-SPME/GC-MS) for natural organic compounds research at the University of Split, Faculty of Chemistry and Technology. A wide variety of headspace compounds from different natural sources has been identified: lower aliphatic compounds (e.g., C5- and C6-compounds), aromatic compounds, monoterpenes (e.g., linalool derivatives (oxides, anhydro-oxides, epoxides), hotrienol), sesquiterpenes (e.g., eudesmol isomers, hydrocarbons), and C9- and C13-norisoprenoids (e.g., 3,4-dihydro-3-oxoedulan, 4-oxoisophorone, trans-β-damascenone). These compounds are important phytochemicals as flavour/fragrance compounds, chemical markers of the botanical origin or others (e.g., allelochemicals, pheromones, or acaricide residue).

Effect of biotic and abiotic stresses on volatile emission of Achillea collina Becker ex Rchb

This study describes the application of headspace solid-phase microextraction (HS-SPME)–gas chromatography/mass spectrometry (GC/MS) to characterise the volatile fingerprint changes of Achillea collina, induced by aphids' infestation, mechanical damage and jasmonic acid (JA) treatment. The volatile organic compound profiles of A. collina, Prunus persica and Pisum sativum infested by Myzus persicae were also compared. Several changes were observed between control, infested, mechanically damaged and JA-treated plants, and new inducible volatile organic compounds (IVOCs) were emitted in response to biotic or abiotic stresses. Some of these were in common for all stresses and other compounds were in common only for two types of stress. Conversely some IVOCs were emitted only in response to the specific stimuli. The results suggested that there were species-specific and common IVOCs emitted by A. collina, P. persica and P. sativum in response to M. persicae infestation. In conclusion, HS-SPME–GC/MS seems to be a reliable analytical approach to study in vivo plant reaction to external stimuli.

Application of Headspace Solid-Phase Microextraction and Gas Chromatography-Mass Spectrometry (HS-SPME-GC/MS) on the Evaluation of Degradation Efficiency of Phenolic Compounds and Identification of By-Products from Produced Water

Application of the headspace solid-phase microextraction and gas chromatography-mass spectrometry (HS-SPME-GC/MS) technique as an analytical tool to monitoring the degradation of phenolic compounds and the formation of by-products in produced water by UV photolysis and UV/peroxide is proposed. All of the experimental conditions for the degradation tests were carried out according to the response of the surface modeling methods developed. The direct photolysis and the UV/H2O2 processes were capable to degrade more than 99% of the initial concentrations of total phenolic components of produced water. The main by-product found was 2,6-di-tert-butylbenzoquinone (DBQ). The presence of DBQ and other hydroxy compounds, constituting the major fraction of by-products identified, demonstrates that the degradations are initiated by the oxidation of the aromatic phenolic ring generating quinones, diphenols, benzoic acids and phenones.

Second order kinetic modeling of headspace solid phase microextraction of flavors released from selected food model systems.

The application of headspace-solid phase microextraction (HS-SPME) has been widely used in various fields as a simple and versatile method, yet challenging in quantification. In order to improve the reproducibility in quantification, a mathematical model with its root in psychological modeling and chemical reactor modeling was developed, describing the kinetic behavior of aroma active compounds extracted by SPME from two different food model systems, i.e., a semi-solid food and a liquid food. The model accounted for both adsorption and release of the analytes from SPME fiber, which occurred simultaneously but were counter-directed. The model had four parameters and their estimated values were found to be more reproducible than the direct measurement of the compounds themselves by instrumental analysis. With the relative standard deviations (RSD) of each parameter less than 5% and root mean square error (RMSE) less than 0.15, the model was proved to be a robust one in estimating the release of a wide range of low molecular weight acetates at three environmental temperatures i.e., 30, 40 and 60 °C. More insights of SPME behavior regarding the small molecule analytes were also obtained through the kinetic parameters and the model itself.

Application of HS-SPME, SDME and Cold-Press Coupled to GC/MS to Analysis the Essential Oils of Citrus sinensis CV. Thomson Navel and QSRR Study for Prediction of Retention Indices by Stepwise and Genetic Algorithm-Multiple Linear Regression Approaches

Volatile fractions in the essential oils (EOs) obtained from the peels of Citrus sinensis CV. Thomson Navel by head-space solid phase micro-extraction (HS-SPME), single drop micro-extraction (SDME) and cold-press (CP) techniques were analyzed by means of gas chromatography-mass spectrometry (GC-MS). Fifteen, nine and fourteen compounds were identified by HS-SPME, SDME and CP methods, respectively representing 99.75 %, 99.45 % and 98.5 % of the chemical profiles in the peels of C. sinensis. The main components were found to be limonene (72.69 %, 71.96 %, 90.40 %), myrcene (9.65 %, 9.80 %, 1.10 %), sabinene (2.63 %, 9.35 %, 0.90 %) and α-pinene (2.00 %, 7.05 %, 1.60 %) by HS-SPME, SDME and CP, respectively. In addition, a quantitative structure-retention relationship (QSRR) study has been developed for prediction of retention indices (RIs) of the occurred natural compounds. The suitable set of molecular descriptors was calculated and the important descriptors were selected by stepwise (SW) and genetic algorithm (GA) variable selection features combined with multiple linear regression (MLR). A comparison between the attained results indicated the superiority of the genetic algorithm over the stepwise in the feature-selection step. The predictive quality of the QSRR models was tested for an external set of five compounds, randomly chosen out of 27 compounds. The genetic algorithm-multiple linear regression model (GA-MLR) with two selected descriptors gave rise in the best predicted results. The accuracy of the proposed GA-MLR model is illustrated using cross-validation, validation through an external test set and Y-randomization evaluation techniques.

Determination of lactones in wines by headspace solid-phase microextraction and gas chromatography coupled with mass spectrometry.

Application of headspace solid-phase microextraction (HS-SPME) coupled with high-resolution gas chromatographic (HRGC) analysis was studied for determining lactones in wines. Six different SPME fibers were tested, and the influence of different factors such as temperature and time of desorption, ionic strength, time of extraction, content of sugar, ethanol, tannins and anthocyanins, and pH and influence of SO2 were studied. The proposed HS-SPME-GC method is an appropriate technique for the quantitative analysis of γ-butyrolactone, γ-hexalactone, trans-whiskey lactone, γ-octalactone, cis-whiskey lactone, γ-nonalactone, γ-decalactone, δ-decalactone, and γ-undecalactone in wines. Method reproducibility and repeatability ranged between 0.6 and 5.2% for all compounds. Detection limit for γ-butyrolactone was 0.17 mg/L and a few μg/L for the rest of the compounds. The optimized method has been applied to several wine samples.

Application of Headspace Solid-Phase Microextraction and Multivariate Analysis for the Differentiation Between Edible Oils and Waste Cooking Oil

Waste cooking oil (WCO) can be recovered and processed into animal feed additives and bio-oils after purification. Unfortunately, edible oils (EOs) were adulterated with refining and purificating WCO, especially in China. Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS) analysis has been applied for the determination of the characteristic volatile profile of pure EOs (sunflower oil, rapeseed oil, and olive oil), WCO, and their mixture. Coupling the HS-SPME/GC-MS analysis data with multivariate analysis (MVA) techniques, such as principal components analysis (PCA) and cluster analysis, it has been possible to classify EOs and WCO on the basis of different volatile compounds. Fresh EOs were characterized by a low number of volatile compounds, while WCO and its mixture are characterized by a prevalence of hexanal, (E)-2-heptenal, hexanoic acid, (E,E)-2,4-decadienal, p-allylanisole esdragol, dihydroanethole, anethole, eugenol, and curcumene. PCA showed similarities in clustering of the data obtained by GC-MS. MVA facilitates comparison of chromatographic profiles of volatile compounds characteristic for various EOs, WCO, and the different oil mixture for monitoring oil quality. MVA has been successfully applied to the analysis of adulterated EOs by the addition of cheaper WCO.

Minor Volatile Compounds in White Wines from Canary Islands, Madeira, and Pico (Azores) by Headspace Solid-Phase Microextraction-Gas Chromatography-Mass Spectrometry: A Qualitative Study

Application of headspace solid-phase microextraction (HS-SPME) coupled with high-resolution gas chromatographic (HRGC) analytical system was studied for detection and identification of volatile compounds in wines. Four different SPME fibers were tested, and 138 different compounds were detected and identified. The best fiber for the determination of different groups of compounds was selected. Using these results, a comparative study of Madeira, Tenerife (Canary Islands), and Pico (Azores) was carried out.

Application of HS-SPME with Poly(1-Vinyl-3-Hexylimidazolium Chloride) Polymeric Ionic Liquid Coating Using GC–MS to Determine Volatile Fatty Acids in Dairy Wastewater

Volatile fatty acids were determined in this study using headspace solid-phase microextraction (HS-SPME) with a poly(1-vinyl-3-hexylimidazolium chloride) polymeric ionic liquid coated fiber followed by gas chromatography–mass spectrometry. Experimental parameters such as extraction time and temperature, sample volume as well as desorption time and temperature were optimized. Detection limits of the method were in the range of 0.13–0.26 mg/L. The coefficient of variation ranged from 0.12 to 6.9 %. The method was applied to determine volatile fatty acids in dairy wastewater from different operations and in bulk wastewater.

Application of headspace solid-phase microextraction followed by gas chromatography–mass spectrometry to determine short-chain alkane monocarboxylic acids in aqueous samples

In this study, a procedure was developed to determine short-chain alkane monocarboxylic acids (SCMAs) in aqueous samples using headspace solid-phase microextraction (HS-SPME) followed by gas chromatography (GC) coupled with mass spectrometry (MS). A Stabilwax-DA capillary column (30 m × 0.32-mm inner diameter, 0.50-μm film thickness) was used for GC separation and a 60-μm poly(ethylene glycol) fiber was used to isolate SCMAs from water and introduce them into the gas chromatograph. Parameters of HS-SPME, analyte desorption, and GC-MS analysis were selected and an analytical procedure was proposed. Limits of quantitation were on the order of about 0.2 mg L-1. As an example of the application of the procedure, SCAMs were determined in municipal wastewater at different steps of treatment.

EVALUATION OF THE VOLATILE FRACTION OF COMMERCIAL VIRGIN OLIVE OILS FROM TUNISIA AND ITALY: RELATION WITH OLFACTORY ATTRIBUTES

The volatile profile of fourteen commercial virgin olive oils (VOOs) produced by Tunisian and Italian olive cultivars from different geographical areas and collected from local markets and farms was evaluated by means of headspace-solid phase microextraction and gas chromatography-mass spectrometry analysis. All the samples were also analyzed by a group of fully trained assessors to define their olfactory attributes. The concentrations of volatile compounds as well as the nuances exhibited large variability among different kind of samples confirming that the typicality of VOOs in terms of both organoleptic and compositional characteristics greatly depends on both olive variety and quality. In particular, VOOs from Chetoui were found to exhibit both volatile profiles and sensory notes very similar to Italian samples. Data relative to the main volatile compounds were related to both positive and negative olfactory notes and sensory defects found in some oil samples were well confirmed by volatile marker presence. PRACTICAL APPLICATIONS Virgin olive oil flavor is strongly connected with the qualitative–quantitative composition of volatile compounds, which determine the whole of olfactory perceptions. This study, carried out on several commercial virgin olive oil samples from different cultivar and geographical origin of Tunisia and Italy revealed that the application of headspace-solid phase microextraction to the analysis of volatile compounds and their identification and quantification by gas chromatography coupled with quadrupolar mass-selective spectrometry can be of great interest not only for the comparison of flavor characteristics of oil samples but also for the evaluation of cultivar-environment influence on virgin olive oil aroma if associated to sensory evaluation performed by an experts' panel.

Application of head-space solid-phase microextraction coupled to comprehensive two-dimensional gas chromatography–time-of-flight mass spectrometry for the determination of multiple pesticide residues in tea samples

A new method has been developed to detect 36 pesticides that may contaminate tea samples (green, black and fruit tea). The hyphenation of solid-phase microextraction in head-space mode with a comprehensive two-dimensional gas chromatography coupled with high-speed time-of-flight mass spectrometry (HS-SPME–GC × GC/TOF MS) proved to be a quick alternative to conventional GC/MS methodology which employs solvent-based extraction. The key parameters for controlling HS-SPME performance were optimized, including fiber coating type, temperature and absorption time settings and tea matrix modification by adding water. Quantification was carried out using matrix-matched calibration. The repeatability of measurements, expressed as relative standard deviation (R.S.D.), was less than 24% for all analytes. The limits of quantification ranged from 1 to 28 μg kg −1. The optimized method was applied to analyze real life samples obtained from a retail market. Results generated by the new SPME procedure and those obtained by using a conventional one involving ethyl acetate extraction and high-performance gel permeation chromatography (HPGPC) clean up agreed with each other for positive (containing residue) samples.

Application of Headspace Solid-Phase Microextraction for Determination of Chloro-Organic Compounds in Sewage Samples

ABSTRACTSolid phase microextraction (SPME) has been optimized and applied to the determination of the volatile halogenated compounds (VHCs) and semi-volatile halogenated compounds (SVHCs). Three types of SPME fiber coated with different stationary phases (PDMS—100 μm, CAR/PDMS—75 μm, PDMS/DVB—65 μm) were used to examine their extraction efficiencies for the compounds tested. Experimental parameters such as the selection of SPME coatings, extraction time, and addition of salts were studied. The carboxen-polydimethylsiloxane (CAR/PDMS) fiber appears to be the most suitable for the determination of VHCs. Analytical parameters such as linearity, limit of detection, and precision were also evaluated. Application of ECD detector for the determination of VHCs and SVHCs allows their determination on the low concentration level, ranging from 0.005 to 0.8 μg/L−1. The HS-SPME-GC/ECD procedure gave good analytical precision expressed as relative standard deviation (RSD) (ranged from 5.08% to 8.07%) for a concentration level of 5 μg/L−1 and good linearity (r2 >0.98) in a wide calibration range. The applied HS-SPME-GC/ECD method was found to be a quick and effective technique for the determination of microtrace amounts of volatile and semi-volatile halogenated compounds in samples containing high amounts of various organic compounds.

Development of a solid phase microextraction-gas chromatography–mass spectrometry method for the determination of pentachlorophenol in human plasma using experimental design

A new method, headspace solid-phase microextraction (HS-SPME) with in situ derivatization and gas chromatography–mass spectrometry (GC–MS), which was used for the determination of trace amount of pentachlorophenol (PCP) in human plasma was presented. The acetylation derivatization reaction was firstly optimized using a Doehlert design. Then a series of parameters relevant to the headspace SPME procedure, including fiber coating, extraction temperature, extraction time and salt addition, were optimized using a two-level full factorial design expanded further to a central composite design. The validation of method showed that the optimized method had good linearity ( R 2 = 0.999) within the concentration ranges 0.1–50.0 ng ml −1, and was sensitive with the limit of detection of 0.02 ng ml −1. Intra- and inter-day precision for pentachlorophenol in human plasma samples were not greater than 11.9% and 12.6%, respectively. The proposed method, to our knowledge, describes the first application of HS-SPME with GC–MS for analysis of PCP in blood plasma sample. Application of the method to real human plasma samples, PCP was successfully detected in some cases at concentration levels 1.2–6.3 ng ml −1.

Development of headspace solid-phase microextraction–gas chromatography method for the determination of solvent residues in edible oils and pharmaceuticals

The application of headspace solid-phase microextraction for isolation and enrichment of solvent residues from oils and pharmaceuticals is discussed. The optimal parameters for isolation and preconcentration of common process solvents (hexane, benzene, toluene and selected chloroderivatives of hydrocarbons) were established. Four fiber types (100 μm polydimethylsiloxane (PDMS), 75 μm Carboxen–PDMS, 65 μm PDMS–divinylbenzene and 85 μm polyacrylate) were evaluated to choose the most efficient coating, able to absorb the greatest amount of analytes. GC–flame ionization detection (FID) and GC–electron-capture detection systems were used for quantitative and qualitative analysis, adequately to the appropriate group of the analytes. For all compounds the limit of detection (LOD), linearity, dynamic range, repeatability and intermediate precision were estimated.