Development of Glass Cup Aqueous Sampling and Headspace Solid-Phase Microextraction/Gas Chromatography-Mass Spectrometry for Measuring Ethanol, Acetaldehyde and Acetone Emission from Human Skin Surface

In the recent past, meat consumption has increased around the world, which resulted in high consumer demand for fresh perilla leaves. The present study aimed at comparison of the volatile organic compounds (VOCs) among three varieties of Perilla frutescens leaves from South Korea via simultaneous distillation extraction (SDE) and headspace solid phase microextraction (HS-SPME). A total of 138 VOCs were identified in leaves of P. frutescens varieties with 111 and 74 VOCs identified by SDE and HS-SPME, respectively. The P. frutescens for. viridis Makino leaves contained the highest concentrations of VOCs for both SDE (17.51 g/kg) and HS-SPME (1.463 g/kg) compared to the other varieties. Perilla ketone was the main volatile in P. frutescens var. acuta Kudo and P. frutescens var. japonica Hara while perilla aldehyde was the major compound in P. frutescens for. viridis Makino. Other major identified compounds were (E)-β-caryophellene, cumaldehyde, limonene, and octanol. Differences in the patterns of functional groups and terpene types were also demonstrated among the varieties. SDE provided more compounds while HS-SPME was more convenient for the determination.

Lagerstroemia caudata is a rare aromatic species native to southeastern China, but its floral scent properties and release dynamics remain unclear. This study is the first systematic analysis of spatial-temporal variation in volatile organic compounds (VOCs) emitted from L. caudata by headspace solid-phase microextraction (HS-SPME) with gas chromatography–mass spectrometry (GC-MS). Thirty-two VOCs were identified, 20 of which were detected for the first time. Aldehydes, alcohols, and monoterpenoids were the main VOC categories, each with different releasing rhythms. Total emission of VOCs was much higher in the full-blooming stage (140.90 ng g−1min−1) than in the pre-blooming (36.54 ng g−1min−1) or over-blooming (24.92 ng g−1min−1). Monoterpenoids, especially nerol, geraniol, and linalool, were the characteristic VOCs for full-blooming flowers. Daily emissions of nine compounds (nerol, geraniol, linalool, citronellol, β-citral, (E)-citral, phenylethyl alcohol, 2-heptanol, 2-nonanol) correlated closely with the opening of L. caudata, presenting an apparent diurnal pattern of scent emission. Tissue-specific emission was found in most isolated floral parts. Stamen was the most significant source of floral VOCs, considering its high emission levels of total VOC (627.96 ng g−1min−1). Our results extend the information on floral VOCs of Lagerstroemia and provide a theoretical basis for breeding new cultivars with desirable floral scents.

Evaluating polyvinylidene fluoride - carbon black composites as solid phase microextraction coatings for the detection of urinary volatile organic compounds by gas chromatography-mass spectrometry

Aroma is an important sensory factor in evaluating the quality of pear fruits. This study used headspace solid-phase microextraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) to analyze the volatile organic compounds (VOCs) of three crispy pears and five soft pears during shelf life, and the changes in soluble solids content (SSC) were analyzed. The results showed that the SSC of the soft pears such as Nanguoli, Jingbaili and Louis was always higher than that of the crispy pears throughout shelf life. A total of 160 VOCs were detected in the eight pear varieties. Orthogonal partial least squares discriminant analysis (OPLS-DA) and hierarchical cluster analysis (HCA) combined with predictor variable importance projection (VIP) showed that the eight pear varieties could be obviously classified into six groups according to the differences in their VOCs, and 31 differential VOCs were screened out, which could be used to differentiate between pears with different flesh textures. The results of clustering heat map analysis showed that, with the extension of shelf life, the content of each different VOC did not change much in crispy pears, whereas the difference in soft pears was larger. This study confirmed the potential of determining the optimal shelf life of different pear varieties about aroma evaluation and studying the mechanism of differences in VOCs in the future.

This study analyzed the volatile organic compounds (VOCs) of four different pineapple varieties (MD2, Sarawak, Josephine and Morris). Head Space-Solid Phase Micro Extraction (HS-SPME) was used to extract the VOCs of those pineapples using Gas Chromatography-Mass Spectrometry (GC-MS). Analysis of pineapples extracts identified many types of VOCS including esters, alcohols, terpenes, aldehydes, ketones, saturated hydrocarbons and phenols. Thirtyfive selected VOCs were used for varietal discrimination using chemometrics techniques namely principal components analysis (PCA), cluster analysis (CA) and discriminant analysis (DA). The application of PCA and CA was able to group the pineapple samples according to their varieties based on their respective VOCs. Standard mode DA had discriminated the samples with 98.75% correctness using all 35 VOCs. The identification of significant compounds found in the studied samples was successfully confirmed (p<0.05) by PCA. The total variance of PC1 and PC2 is 63.34% exhibiting that the ester compounds show strong and moderate loading values. One of the unique identifiers is the presence of β-Myrcene with a loading value 0.93 found in PC1 where it is described as pleasant terpenes odor and balsamic descriptor. GCMS and chemometric techniques provided meaningful chemically quantitative data.

Electrospinning composites of polyvinylidene fluoride - carbon black on solid phase microextraction fibers for enhanced detection of volatile organic compounds by gas chromatography-mass spectrometry

This study was designed to analyze the volatile organic compounds in the leaves of Ambrosia artemisiifolia L. and Artemisia annua L. from Korea. For extraction of volatile compounds, headspace-solid phase micro extraction (HS-SPME) and simultaneous distillation extraction (SDE) were applied and analyzed by gas chromatography/mass spectrometry (GC/MS). From the results, SDE extraction was found to give the highest concentration of volatile compounds with an average concentration of 1,237.79 mg/kg for A. annua L. leaves compared to 1,122.73 mg/kg by HS-SPME technique. A total of 116 volatile organic compounds were identified, including 76 similar volatile organic compounds detected by both the methods of extraction in leaves of subject species at varying concentrations. Among these 33 volatile organic compounds were reported for the first time from the subject plant species. Thus the present research findings extend the characterization of volatile organic compounds from leaves of A. annua L. and A. artemisiifolia L. species and reported some distinguishing compounds which may be used for their discrimination.

Volatile organic compounds (VOCs) are the metabolites of microorganisms. VOCs are low molecular weight and easily evaporate at room temperature, all odorants are VOC. VOCs are different depending on health status and reproductive status. The objective of this study was to profile the VOCs in bitches during estrous cycle, and to compare VOCs between stages of estrous cycle and between pre-ovulatory, ovulation and post-ovulatory periods. A total of 23 normal, healthy bitches requested for ovulation timing as part of the routine breeding management were used in this study. All animals had a previous history of normal estrous cycle without any reproductive abnormalities or any urogenital disorders. Samples of cranial vaginal swab including 51 proestrus, 59 estrus, 7 diestrus and 4 anestrus were collected every other day, started when onset of proestrus was observed until cytologic diestrus was found on vaginal cytology. Determine reproductive stages using vaginal cytology and time ovulation with serum progesterone via chemiluminescent assay (Allinity i® Abbott, Illinois, USA). VOCs was analyzed by headspace solid-phase microextraction with gas chromatography-mass spectrometry (HS-SPME-GC-MS). A total of 203 detected peaks were found, with 142 identified as identifiable peaks, and only 41 were considered potential VOCs. When comparing potential VOCs across reproductive stages, we observed varying VOC profiles. Specifically, Propylene Glycol showed upregulation in proestrus with an accuracy of 58.4%, while group 1A-D exhibited downregulation in proestrus with accuracies of 66.3%, 64.4%, 64.4%, and 63.4%, respectively. In the estrus stage, VOCs before ovulation differ from those during and after ovulation. Group 2A-C showed upregulation during the pre-ovulatory period with accuracies of 80%, 80%, and 84%, respectively. Using the combined feature of PLS-DA enhances the accuracy of predicting stages based on VOCs. Specifically, it achieves 84.2% accuracy for detecting downregulation in proestrus and 98.8% accuracy for detecting downregulation in the pre-ovulatory period. In conclusion, these findings demonstrate that VOC profiles vary across different stages of the reproductive cycles in female dogs. Certain VOCs can serve as predictors or biomarkers for these stages. Integrating this knowledge with other tools such as clinical observations, vaginal cytology, and serum progesterone levels could potentially enhance the detection of ovulation in dogs using VOCs as a non-invasive diagnostic tool.

The main objective of this study was to explore the composition and distribution of volatile organic compounds (VOCs) and the factors that affect their distribution in the salt lake sediments. Thirteen sediment samples were collected from a depth profile in the East Taijinar Lake, China. VOCs of different samples were extracted by headspace solid phase microextraction. Gas chromatography-ion mobility spectrometry, gas chromatography-mass spectrometry, and X-ray diffraction were used to analyze the VOCs, n-alkanes, and minerals present in samples. Thirty-four VOCs were identified and classified into seven types, including terpenes, furans, esters, aldehydes, ketones, alcohols, and acids, apart from six contaminants. It was found that 24 of the most prevalent compounds in clay were on average 101.45% higher than those in sandstone and halite because of the sedimentary environment, while the remaining ten (2-acetylfuran, 2-pinene D, etc.) were on average 13.27% higher in sandstone and halite sediments than in clay. This can be attributed to their different biological sources, porosity, and higher salinity. Based on the Q-cluster analysis, the 13 sediment samples were split into two groups, including the group according to composition and the group based on distribution of VOCs. In this study, it was found that the VOCs correlate positively with detrital minerals, with Group I exhibiting a high content of detrital minerals (>25%), while Group II showed the opposite characteristics. The consumption of organic matter (OM) by microorganisms leads to the formation of VOCs in sediment. The values of carbon preference index and n-alkane further demonstrate that the organic matter of the two groups came from different sources, exogenous and endogenous. Pr/Ph ratios, Pr/C17, and Pr/C18 also suggest that the OM in all sediments was strongly affected by microorganisms in an anoxic environment. Together, these results demonstrate that the OM from different biological sources and microbial activities played a critical role in deciding the composition and distribution of VOCs in the sediment. This study also shows that the proportion of VOCs in halite was discernably higher than that in clay and sandstone and that the content of VOCs should be considered when studying OM in salt lake sediments.

The equilibrium rather than the exhaustive nature of headspace single-drop microextraction (HS-SDME) and headspace solid-phase microextraction (HS-SPME) allowed the concurrent sampling of volatile organic compounds (VOCs) on the same sample in the same vial in a dual extraction configuration. This has avoided the necessity of conducting a separate set of experiments and was found to produce results in the time duration of a single sample preparation experiment. The results obtained by HS-SDME were validated against those found by the standard method of HS-SPME. Rectilinear calibration was made for certain VOCs tested as analytes over the range of 0.01-8 μg g-1, and the average values of R2, LOD and LOQ were found to be, respectively, 0.9992, 1.9 ng g-1 and 5.7 ng g-1 in HS-SDME, and 0.9991, 3.1 ng g-1 and 9.1 ng g-1 in HS-SPME. The spiked recoveries and RSD were, respectively, 100.5% and 3.3% in HS-SDME and 98.1% and 3.6% in HS-SPME. HS-SDME is convenient to perform and produce results in a much cheaper way than HS-SPME and free from the inconveniences of memory effects. With GC-MS, this method has also been implemented as a rapid, reliable and green procedure (by GAPI and AGREE tools) for the sampling of VOCs in real samples of spices, flowers, and a beetle nut chewing sample illicitly containing tobacco.

For over three decades our laboratory has been developing and improving methods for quantifying toxic volatile organic compounds (VOCs) in blood in support of numerous national and regional studies, including nine National Health and Nutrition Examination Survey (NHANES) cycles. Absorption of VOCs most commonly occurs through inhalation, as 100% of blood circulates to the lungs for exchange with alveolar gas. The high blood:gas partition ratios of most VOCs favor preconcentration in the blood, but blood VOC equilibration with tissues and organs is what influences VOC elimination half-life. As such, VOC analysis in blood is best-suited for compounds that are stable in the body by offering a direct measure of VOC burden experienced by tissues and organs.The current analysis method uses headspace solid-phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS). Important to the success of this method is the use of isotopically labeled analogs specific to every compound to compensate for competition effects in the headspace and SPME fiber, as well as adsorption and volatilization losses. The combination of these techniques has enabled us to simultaneously quantify a broad array of VOCs (boiling points from 32 to 204 °C) in the low parts-per-trillion (ng/L) range from a 3-mL blood sample.This presentation will include an overview of the blood VOC method and describe recent improvements to achieve accuracy and precision of < 15% for nonpolar compounds (e.g., alkanes) and within 5% for most of the other VOCs. We will also describe noteworthy blood VOC trends in the United States and reveal new analytes that are to be included in future studies and NHANES cycles. In addition to individual VOC trends, we will describe recent work comparing relative VOC levels among participants using artificial neural networks as a means to objectively distinguish exposure between different VOC sources within a large population.

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic disorder that markedly impairs quality of life. Current diagnostic and monitoring tools rely on invasive procedures such as endoscopy, which are costly and burdensome. Volatile organic compounds (VOCs) in breath and feces, reflecting host-microbiota metabolism, have emerged as promising non-invasive biomarkers, but their clinical utility remains underexplored.This study aimed to identify breath- and feces-derived VOCs as novel biomarkers for IBD and to establish artificial intelligence (AI)-based predictive models for non-invasive diagnosis and disease activity monitoring. The relationship between VOC alterations and gut microbiota dysbiosis was also investigated. A total of 279 participants (131 IBD patients, 148 healthy controls) were enrolled. VOCs from breath and fecal samples were analyzed using gas chromatography-ion mobility spectrometry (GC-IMS). AI-based machine learning models were developed for diagnosis and monitoring. Furthermore, the differences in breath VOCs identified in human cohorts were validated in a DSS-induced colitis mouse model (2% DSS for 7 days). In a subset of 62 individuals, 16S rDNA sequencing characterized gut microbiota composition and its correlation with VOCs. Distinct VOC profiles were identified in IBD. Ethyl sulfide and furfural were elevated in breath samples, while hexanoic acid, pentanoic acid, thiophene, and ethyl acetate were reduced. In fecal samples, dimethyl trisulfide increased, whereas several short-chain fatty acids(SCFAs) and alcohols decreased. The diagnostic model achieved an AUC of 0.92 (sensitivity 96%, specificity 71%), and the monitoring model an AUC of 0.88, both outperforming C-reactive protein and fecal calprotectin. Validation in a DSS-induced colitis model confirmed eight discriminatory VOCs, characterized by depleted SCFA-related VOCs and elevated sulfide VOCs, underscoring their robust correlation with the development and severity of intestinal inflammation. IBD patients showed reduced microbial diversity and depletion of short-chain fatty acid-producing bacteria, closely correlated with altered VOC profiles. This study demonstrates that integrating volatomics with AI-based modeling enables accurate, non-invasive diagnosis and monitoring of IBD. The cross-species consistency observed in our human cohorts and DSS-induced colitis mice confirms the reliability of specific VOCs as conserved inflammatory biomarkers. These findings, coupled with VOC-microbiota associations, offer profound mechanistic insights and a promising platform for biomarker-guided precision care. ChiCTR, ChiCTR2300073475. Registered 12 July 2023-Prospectively registered, https://www.chictr.org.cn/bin/project/edit?pid=201603 .

Aroma, which plays an essential role in food perception and acceptability, depends on various mixture of volatile organic compounds (VOCs). Meanwhile, as a field of metabolomics, VOC analysis is highly important for aroma improvement and discrimination purposes. In this work, VOCs in pear fruits were determined via headspace solid-phase micro-extraction (HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS) to study variations among different cultivars and storage stages. In 12 cultivars of pear fruits, a total of 121 VOCs were quantified, including 40 esters, 32 alcohols, 16 aldehydes, 13 alkenes, 11 ketones, 4 acids, and 5 other compounds. The types and amounts of VOCs in different cultivars varied dramatically, which were in the range of 13-71 and 3.63-55.65 mg/kg FW (fresh weight), respectively. The Dr. Guyot cultivar showed the highest level of VOCs, both in type and amount. After 21 days storage at 4 °C, total concentration of VOCs increased from initial levels of 50.76 to 101.33 mg/kg FW. Storage at 20 °C made a larger contribution to production for VOCs than that at 4 °C, resulting in the maximum content of VOCs (117.96 mg/kg FW) in fruit after 14 days storage at 4 °C plus 7 days at 20 °C. During storage, the content of esters showed a gradual increase, while the content of alcohols and aldehydes decreased. Based on the results presented, related alcohols were recognized as the intermediates of conversion from aldehydes to esters.

Current article presents a methodological approach for a comparative study of the composition of volatile organic compounds ( VOCs ) in a natural product and a nature-identical flavoring substance. The identification of VOCs was performed by gas chromatography-mass spectrometry without reference compounds. The identification was made based on coincidence of the experimental and reference mass spectra and linear retention indices. During the first step, the closest match factor substance was selected based on the library search. During the second step, the result was verified by the means of experimental and reference retention indices data proximity. The reference retention indices were selected considering the identity of the experimental conditions (chromatographic stationary phase, temperature programming mode). The impossibility of identification of aroma components in acetonitrile extract of fragrance was shown due to the overlapping of their peaks with peaks of di- and tri- glycerides of fatty acids. The extraction and concentration of VOCs from vapor were carried out using the head space solid-phase microextraction. The fragrance content investigation revealed 39 volatile organic compounds including propylene glycol and triacetin as the markers of synthetic fragrances. In natural cocoa butter, also 39 volatile organic compounds were identified. All of them were common for the fermented cocoa beans. Pyrazines derivatives, characteristic of cocoa aroma, were presented with the following 7 components: 2,3-dimethylpyrazine; 2,5-dimethylpyrazine; ethylpyrazine; 2-methyl-6-ethylpyrazine; 2,3,5-trimethylpyrazine, 2,5-dimethyl-3-ethylpyrazine; tetramethylpyrazine. In quantitative terms, the isomeric 2,3-butandiols predominate in the head space of natural cocoa butter accounting for 37 percent of total VOC content. The analytical technique used allows investigation of multicomponent objects including the heterogeneous ones. Key words: gas chromatography-mass spectrometry, head space solid-phase microextraction, mass spectra, retention indices, fragrance DOI: http://dx.doi.org/10.15826/analitika.2020.24.1.003 E. Savelieva E. Kessenikh and L. Gustyleva Research Institute of Hygiene, Occupational Pathology and Human Ecology, g/p Kiz’molovskii, Vsevolozhskii raion, Leningradskaia oblast’, 188663, Russian Federation

An analytical method for the detection of 14 volatile organic compounds (VOCs) was developed to investigate VOCs in refill fluids and cartridges of electronic cigarettes (EC) using headspace solid-phase micro extraction (HS-SPME) coupled with gas chromatography-mass spectrometry (GC-MS). In total, 14 VOCs were identified and quantified in 283 flavored liquids, 21 nicotine liquids, and 12 disposable cartridges. The detected concentration ranges of the VOCs are as follows: benzene (0.008-2.28mgL-1), toluene (0.006-0.687mgL-1), ethylbenzene (0.01-1.21mgL-1), m-xylene (0.002-1.13mgL-1), p-xylene (0.007-2.8mgL-1), o-xylene (0.004-2.27mgL-1), styrene (0.011-0.339mgL-1), ethyl acetate (0.3-669.9mgL-1), ethanol (16-38,742mgL-1), methanol (66-3375mgL-1), pyridine (0.077-99.7mgL-1), acetylpyrazine (0.077-147mgL-1), 2,3,5-trimethylpyrazine (0.008-96.8mgL-1), and octamethylcyclotetrasiloxane (0.1-57.2mgL-1). Benzene, toluene, ethylbenzene, m-xylene, p-xylene, and o-xylene coexisted in samples, which may have originated from the use of petrogenic hydrocarbons as an extraction solvent for flavor and nicotine from natural plants. The maximum detected concentrations of benzene, methanol, and ethanol in liquid samples were found in quantities higher than their authorized maximum limits as residual solvents in pharmaceutical products.