In this study, 48 genuine absolute samples of Egyptian J. grandiflorum across three harvest seasons (2022-2024) were analysed using gas chromatography coupled to mass spectrometry and flame ionization detector (GC-MS/FID), alongside sensory evaluation to assess variations linked to harvest times. Identification of volatile compounds and sensory analysis revealed seasonal differences. Principal component analysis (PCA) further highlightedvolatile markers that differentiated sample subsets according to their seasonal profiles. Given jasmine absolute's high commercial value, authenticity assessment is crucial to avoid possible adulteration. In this study, for the first time, enantioselective multidimensional GC coupled to isotope ratio mass spectrometry (MDGC-C-IRMS/qMS) was applied to jasmine absolute, enabling simultaneous determination of enantiomeric ratios and delta 13C isotopic signatures within a single analytical workflow. Furthermore, typical delta 13C isotopic signatures were registered for (-) and (+) linalool and indole across the seasons, providing potential novel markers for jasmine absolute authenticity, and quality control.

Recent studies have shown that essential oils (EOs) from spices are effective in reducing high blood glucose levels, with β-caryophyllene (BCP) emerging as one of the most promising bioactive compounds. Despite the increasing interest in this field, few studies in the literature have elucidated the link between sample components and their resulting biological activities. In this paper, a detailed investigation was carried out, using a black pepper EO as a case study, and α-glucosidase as biological target. Initial biological assays showed very similar activities between the entire EO and the corresponding amount of BCP in the EO on α-glucosidase. These outcomes confirmed the manifest role of BCP, and further suggested that EO’s fractionation could help to unravel the complex interactions among terpene families, BCP, and the biological target. As a first step, a suitable preparative GC method was developed to enable the effective and rapid isolation of the separated monoterpene and sesquiterpene families for subsequent biological assays. The biological outcomes bio-guided consequent fractionation procedures, which were aimed at understanding the role of BCP in the overall sesquiterpene family. Consequently, the use of multidimensional preparative GC guaranteed the effective isolation of the sesquiterpene family without BCP, underscoring its relevant role in this fraction. In a complementary approach, the sesquiterpene family was further fractionated to understand potential enhancing/inhibitory effects with BCP. To the best of authors’ knowledge, this paper represents the first instance in the literature where preparative gas chromatography has been employed as an analytical approach to carry out a bio-guided fractionation of EOs.

The flavour quality of chili peppers results from the interplay between volatile aroma and pungency perception. This study applies a multi-technique approach integrating complementary analytical techniques and sensory evaluation to comprehensively characterize nine chili pepper cultivars from Capsicum chinense, baccatum, and annuum accessions. Volatile organic compounds (VOCs) and odor-contributing volatiles (OCVs) were profiled using headspace solid-phase microextraction-gas chromatography-olfactometry/mass spectrometry (HS-SPMEGC-O/MS) and headspace solid-phase microextraction-gas chromatography-flame ionization detection (HSSPME-GC-FID). Capsaicinoids were quantified by ultra-high performance liquid chromatography-ultraviolet detection (UHPLC-UV) and expressed as Scoville Heat Units (SHU). Sensory evaluation included aroma profiling and pungency assessment. More than 200 VOCs were detected, with C. chinense dominated by branched-chain esters, whereas C. baccatum and C. annuum enriched in alcohols, terpenes, and hydrocarbons. Despite the compositional complexity, aroma perception was mainly driven by a restricted set of OCVs, while sensory pungency showed cultivar-dependent variability even under standardized SHU conditions. The integration of sensory and instrumental datasets highlights the chemical complexity underlying chili pepper flavour, demonstrating that aroma and pungency perception arise from complex metabolite interactions. These findings provide a robust framework for chili pepper quality assessment and support product characterization, authenticity evaluation, and flavour optimization in chili-based food products.

BACKGROUND:Given the increasing interest in natural compounds for therapeutic applications, understanding the contribution of individual components within complex essential oils (EOs) is crucial. The isolation is often achieved through bio-guided fractionation, typically using flash chromatography to target chemical classes. To refine this, some methods rely on customized reconstitution using reference standards, which is challenging due to issues with preserving natural abundances and enantiomeric ratios. RESULTS:This study compares conventional flash chromatography with an advanced preparative multidimensional gas chromatography (prep-GC) system, equipped with a novel collection setup. This prep-GC approach enabled the isolation of sub-fractions at the milligram scale for biological assays. Critically, it preserved the natural distribution of chiral components, eliminating the need for standard-based reconstitution and its associated challenges. Mentha × piperita L. EO, known for its inhibitory activity against butyrylcholinesterase (BChE), an enzyme relevant to Alzheimer's disease, was chosen as a case study. The novel approach allowed for a comprehensive investigation by isolating the oxygenated fraction devoid of menthol. This facilitated a direct comparison of the biological activity of the whole EO against the total oxygenated fraction (from flash chromatography) and the menthol-devoid fraction (from prep-GC), as well as pure (-)-menthol, pure (-)-menthone, and their mixture. SIGNIFICANCE:The results clearly indicate that (-)-menthol, (-)-menthone, and other terpenes within the oxygenated fraction jointly contribute to the overall BChE inhibitory activity. These findings highlight the complex interplay among Mentha × piperita L. EO constituents. Furthermore, this study underscores the potential of this new prep-GC technology for uncovering the biological roles of minor constituents in complex natural mixtures, by removing the contribution of the main representative components.

BACKGROUND:The separation of enantiomers via chiral gas chromatography remains a pivotal area of research in analytical chemistry, driven by its critical role in the quality control of high-value products. Recent helium shortages and escalating costs have necessitated the exploration of alternative carrier gases, such as nitrogen and hydrogen. Maintaining optimal resolution is paramount, as co-elution directly impacts the accuracy of enantiomeric ratio determination and, consequently, the reliability of analytical data. Given that resolution is a function of efficiency, selectivity, and retention, a thorough investigation of these parameters is essential to optimize enantiomeric separations when comparing different carrier gases. RESULTS:In this study, a comprehensive comparison of nitrogen, helium, and hydrogen as carrier gases was conducted using bergamot essential oil as a model sample on a commercially available cyclodextrin (CD) column. The analysis revealed distinct chromatographic profiles, underscoring the importance of selecting the appropriate carrier gas and chromatographic conditions for specific separation challenges. Notably, hydrogen demonstrated superior performance compared to helium, exhibiting higher resolution at elevated linear velocities. However, the analysis of a real sample highlighted significant limitations, including co-elution of chiral components with each other and with achiral compounds. To address these issues, the separation was optimized by joining two chiral stationary phases. The strategic arrangement of chiral selectors within this tandem phase column facilitated enhanced separation of critical enantiomeric pairs. This approach yielded significant improvements in enantiomer resolution, both amongst themselves and in relation to non-chiral compounds, compared to the conventional column. SIGNIFICANCE:These findings offer insights into the design and application of tandem chiral stationary phases for the analysis of chiral components in essential oils. The ability to fine-tune separation selectivity through the strategic combination of chiral selectors, optimization of chromatographic parameters, and judicious selection of carrier gas represents a significant advancement. This comprehensive approach provides a powerful tool for tackling challenging separations and holds broad implications for the quality control and authentication of essential oils and related products.

The current study aimed to provide a comprehensive analytical profile of the volatile fraction of sixty-three genuine mandarin essential oil (EO) samples, by exploiting a single instrument. For this purpose, a novel analytical approach was implemented, based on a heart-cut enantio‑selective multidimensional gas chromatographic system coupled in parallel to an isotopic ratio mass spectrometer and a single quadrupole mass spectrometer (Es-MDGCC-IRMS/qMS). For the first time, the stand-by analysis in the first dimension, usually employed to transfer target compounds to the second dimension, was here utilized to perform quali-quantitative analyses. Furthermore, the second dimension, equipped with a chiral stationary phase and coupled to a qMS and an IRMS, allowed the simultaneous evaluation of selected target components' chiral and carbon isotopic ratios. To the best of the Authors' knowledge, this research reports for the first time the δ¹³C values of specific enantiomers in mandarin EOs. The data gathered from Es-MDGCC-IRMS/qMS analyses revealed clear seasonal and geographical trends, while chemometric investigation confirmed the validity of the results obtained. This method allowed us to overcome the limitations associated with a monodimensional GC approach, while substantially reducing total analysis time, energy use, solvent consumption, and waste production, making it a powerful tool for authenticity assessment.

An investigation into cold-pressed finger lime essential oils (Citrus australasica) was conducted utilizing both liquid and gas chromatographic techniques. Samples were collected throughout the entire productive season, spanning from October 2022 to June 2023. This research aimed to elucidate the composition of non-volatile oxygen heterocyclic components using RP-HPLC-QqQ/MS and to analyze the volatile fraction using GC-FID. Additionally, the enantiomeric ratios of selected volatile components were determined through multidimensional GC (MDGC) with a chiral column in the second dimension. This study provides insight into the composition of Calabrian finger lime essential oils , offering valuable information for identifying quality parameters, essential for the analytical characterization of this product. To the best of the authors' knowledge, this is the first report characterizing coumarins and furocoumarins in cold-pressed finger lime essential oils. Furthermore, the investigation includes the analysis of thirteen chiral couples, eight of which for the first time in the literature.

Wide-bore capillary columns (0.53 mm I.D.) are frequently employed in preparative gas chromatography due to their enhanced sample capacity than the micro-bore counterparts. However, the increased carrier gas flow rates required, especially in multidimensional separations, leads to elevated consumption. Helium is the most used carrier gas thanks to its superior chromatographic performance and inertness, which mitigates safety concerns in routine use. However, helium has experienced supply shortages and rising costs in recent years. This study aimed to evaluate more sustainable carrier gases than helium in preparative multidimensional gas chromatography. In the first stage, the chromatographic performance of nitrogen, hydrogen, and helium was compared on columns equipped with diverse stationary phases using GC-FID. In the second step, the performances of hydrogen and nitrogen were benchmarked against helium in a prototype preparative multidimensional gas chromatographic system. A lemon essential oil was utilized to assess the impact of these carrier gases. Despite a minor variation in terms of total analysis time, comparable chromatographic profiles were achieved with each carrier gas. Our findings indicate that hydrogen and nitrogen, particularly the latter owing to its inherent inertness and safety profile, can represent viable alternatives to helium in preparative multidimensional gas chromatography. These gases offer comparable chromatographic performance while addressing the helium's increasing costs and supply constraints.

Among the Moscato grapes, Moscato Giallo is a winegrape variety characterised by a high content of free and glycosylated monoterpenoids, which gives wines very intense notes of ripe fruit and flowers. The aromatic bouquet of Moscato Giallo is strongly influenced by the high concentration of linalool, geraniol, linalool oxides, limonene, α-terpineol, citronellol, hotrienol, diendiols, trans/cis-8-hydroxy linalool, geranic acid and myrcene, that give citrus, rose, and peach notes. Except for quali-quantitative analysis, no investigations regarding the isotopic values of the target volatile compounds in grapes and wines are documented in the literature. Nevertheless, the analysis of the stable isotope ratio represents a modern and powerful tool used by the laboratories responsible for official consumer protection, for food quality and genuineness assessment. To this aim, the aromatic compounds extracted from grapes and wine were analysed both by GC-MS/MS, to define the aroma profiles, and by GC-C/Py-IRMS, for a preliminary isotope compound-specific investigation. Seventeen samples of Moscato Giallo grapes were collected during the harvest season in 2021 from two Italian regions renowned for the cultivation of this aromatic variety, Trentino Alto Adige and Veneto, and the corresponding wines were produced at micro-winery scale. The GC-MS/MS analysis confirmed the presence of the typical terpenoids both in glycosylated and free forms, responsible for the characteristic aroma of the Moscato Giallo variety, while the compound-specific isotope ratio analysis allowed us to determine the carbon (δ13C) and hydrogen (δ2H) isotopic signatures of the major volatile compounds for the first time.

The study describes the effectiveness of a 3D GC system coupled with olfactometric detection and simultaneous MS and FID (3DGC-O-MS/FID) to improve the detection of odorants. Mega-bore columns were used to ensure a sample capacity able to enhance the odour perception. The heart-cut approach allowed to overcome the low efficiency of wide-bore columns, granting to purify enriched target fractions before olfactometry detection. After the third GC dimension, the isolated target peaks were eluted to the olfactometric port allowing the odour to last multiple seconds, making the panelist's perception easier and more comfortable. The simultaneous FID/MS detection after the third GC dimension allowed to match specific odours to target molecules and their concentration in the sample. The 3DGC-O-MS/FID system boosts odour perception of trace components compared to conventional GC-O approaches. A reduced detection threshold of mg/kg levels was obtained compared to the mg/kg levels typical of monodimensional GC-O.

The request for novel hyphenated instruments and techniques, capable of affording exhaustive information and results, is a focus continuously watched out. In this context, the present work aimed at the development of an integrated system combining gas chromatographic (GC) separation with mass spectrometry (MS) and (solid deposition) Fourier transform infrared spectroscopy (FTIR) detection. An external transfer line was designed in the lab for the parallel coupling of the two detectors, in such a way to obtain complementary analytical information consisting of an MS spectrum, an IR spectrum and linear retention indices (LRI), within a single analysis. The instrument performance was demonstrated for the analysis of a commercial mixture consisting of 139 hydrocarbons, comprising linear, branched, unsaturated and aromatic compounds. A 100-m poly(dimethylsiloxane) column was employed for the separation, and the outlet flow was split 95:5 between the IR and MS detectors using two uncoated capillaries. The IR spectra were acquired from solid deposits on a zinc selenide disc (−90 °C), over a spot (detector area) of about 0.1 mm2, in the range of 4000–700 cm−1 and at a resolution of 4 cm−1. Final identification of the separated compounds by a library search was achieved by excluding incorrect results, sequentially using a three-filter approach (85

In this study, multiple analytical approaches, including simultaneous enantiomeric and isotopic analysis, were employed to thoroughly investigate the volatile fraction in Moscato giallo grape berries and wines. For the qualitative and quantitative profiling, a fast GC-QqQ/MS approach was successfully utilized. However, prior to isotopic analysis, the extracts underwent an additional concentration step, necessitating an assessment of isotopic fractionation during the concentration process. Once the absence of carbon isotopic fractionation was confirmed, this research aimed to develop a suitable gas chromatographic method for the simultaneous detection of both enantiomeric and isotopic ratios of target monoterpenoids in Moscato giallo samples. To address the limitations associated with a one-dimensional approach, multidimensional gas chromatography was employed to enhance separation before IRMS and qMS detections. Utilizing a Deans switch transfer device, the coupling of an apolar column in the first dimension and a chiral cyclodextrin-based stationary phase in the second dimension proved effective for this purpose. The data obtained from the analysis of Moscato giallo samples allowed for the assessment of natural isotopic and enantiomeric distributions in grapes and wines for the first time in the literature. Significant enantiomeric excesses were observed for the target terpenoids investigated. Regarding isotopic distribution, a consistent trend was observed for all detected target terpenols, including the linalool enantiomers. To date, this study represents the first investigation of simultaneous δ13C and chiral investigation of the main terpenoids in oenological products in the literature.

Piper gaudichaudianum Kunth essential oil (EO) is a natural source of bioactive components, having multiple therapeutic applications. Its chemical composition is highly variable, and strictly depends on abiotic factors, resulting in various biological activities. The present study details the utilization of multiple gas chromatographic techniques alongside nuclear magnetic resonance (NMR) spectroscopy to characterize the essential oil of Piper gaudichaudianum Kunth from Brazil. Seventy-six components were identified using GC-MS analysis, while enantio‑selective multidimensional gas chromatography elucidated the enantiomeric distribution of eight chiral components, for the first time in the literature. Following GC-MS analysis, an unidentified component, constituting approximately 27 % of the total oil, prompted an isolation step through preparative gas chromatography. Through the combined use of nuclear magnetic resonance, GC-Fourier transform infrared spectroscopy (FTIR), and mass spectrometry (MS), the unknown molecule was structurally identified as 4-[(3E)‑dec-3-en-1-yl]phenol. Remarkably, it was identified as a known molecule, gibbilimbol B, and not previously listed in any MS database. Subsequently, the spectrum was included in a commercial library, specifically the FFNSC 4.0 MS database, for the first time.

This research aimed to support police forces in their battle against illicit drug trafficking by means of a multi-technique approach, based on gas chromatography. In detail, this study was focused on the profiling of volatile substances in narcotic Cannabis sativa L. flowering tops. For this purpose, the Scientific Investigation Department, RIS Carabinieri of Messina, provided 25 seized samples of Cannabis sativa L. The content of Δ9-tetrahydrocannabinol (THC), useful to classify cannabis plant as hemp (≤ 0.2%) or as marijuana (> 0.2%), was investigated. Essential oils of illicit drug samples were extracted using a microwave-assisted hydro-distillation (MAHD) system; GC-MS and GC-FID analytical techniques were used for the characterization of the terpenes and terpenoids fingerprint. Furthermore, the enantiomeric and carbon isotopic ratios of selected chiral compounds were investigated using a heart-cutting multidimensional GC (MDGC) approach. The latter exploited a combination of an apolar column in the first dimension, and a chiral cyclodextrin-based column in the second one, prior to parallel carbon isotope-ratio mass spectrometry (C-IRMS) and MS detection. Finally, all the data were gathered into a statistical model, to demonstrate the existence of useful parameters to be used for the classification of seized samples.

Separation science plays a crucial role in the isolation of novel compounds contained in complex matrices. Yet their rationale employment needs preliminary structure elucidation, which usually requires sufficient aliquots of grade substances to characterize the molecule by nuclear magnetic resonance experiments. In this study, two peculiar oxa-tricycloundecane ethers were isolated by means of preparative multidimensional gas chromatography from the brown alga species Dictyota dichotoma (Huds.) Lam., aiming to assign their 3D structures. Density functional theory simulations were carried out to select the correct configurational species matching the experimental NMR data (in terms of enantiomeric couples). In this case, the theoretical approach was crucial as the protonic signal overlap and spectral overcrowding were preventing any other unambiguous structural information. Just after the identification through the density functional theory data matching of the correct relative configuration it was possible to verify an enhanced self-consistency with the experimental data, confirming the stereochemistry. The results obtained further pave the way toward structure elucidation of highly asymmetric molecules, whose configuration cannot be inferred by other means or strategies.

Within extra-virgin olive oil (EVOO) global market, there is a niche market of olive oils flavoured with aromatic and medicinal plants. The use of aromatic and medicinal plants to flavour extra-virgin olive oils enriches the oil both from a sensorial and nutritional point of view, affecting its chemical composition. It is, therefore, necessary to develop analytical techniques useful to investigate in deeply the quali-quantitative profile of molecules contained in both the volatile and non-volatile fractions of extra-virgin olive oil. In the current study, several flavoured EVOOs (with truffle, basil, cardamom, bergamot, lemon, mandarin, sage, porcini mushroom, garlic, and rose) were purchased from local stores and analysed by both HPLC and GC methods to verify the correspondence with the profile of the added aroma. Furthermore, considering the preciousness and cost of some specific flavouring ingredients, in some cases, multidimensional gas chromatographic approach coupled to IRMS or performed by a chiral separation (Es-MDGC) was led to investigate their authenticity. From the results obtained, these complementary approaches allowed confirming the genuineness for most of the flavoured EVOOs. For few flavourings, some differences were detected with respect to literature references, thus requiring additional analytical devices to further authenticate their genuineness.

Supercritical fluid chromatography (SFC) has witnessed a resurge of interest in the last decade, motivated by substantial progress in hardware capabilities and the development of specifically tailored packing materials. Meanwhile, the technique has been transitioning to the use of mobile phases in which an organic co-solvent is mixed to carbon dioxide under subcritical conditions (subFC). The use of a mobile phase modifier will also affect the selectivity, and extend the range of SFC-amenable compounds, including lipids. In this research, a subFC method was developed for the separation of triacylglycerols (TAGs) in edible oils of vegetable origin, namely borage, corn, hazelnut, olive, palm, peanut, and soybean oil. For all the samples investigated, elution of the TAG species was achieved within 8 min, the only exception being borage oil (14 min run), characterized by TAGs spanning in a wide range of partition number (PN 36–56), as constituted by fatty acids differing for alkyl chain lengths (CN 14–24), and degree of unsaturation (DB 0–9). The coupling to mass spectrometry (MS) detection allowed for the average parameters of fatty acid composition to be derived in the oil TAG constituents. A total of 121 TAGs were identified by subFC-MS, with reduced analysis time and solvent consumption (1.5 mL per analysis) compared to common chromatographic approaches. Key features of the method developed hereby are low toxicity, costs, and environmental impact. Notably, the achieved separations were conducted at room temperature, which is beneficial in terms of column life.

The present research aimed to retrieve key information about the genuineness of Sicilian lemon essential oils by evaluating simultaneously the chiral and isotopic data of target terpene components. With respect to previous literature references, where chiral recognition and isotope discrimination were performed by distinct gas chromatographic methods, this study aimed to develop a single analytical approach. To overcome limitations associated to monodimensional gas chromatographic approaches, an enantio‑selective multidimensional gas chromatographic approach coupled to isotopic ratio mass spectrometry and to parallel single quadrupole detection (Es-MDGC-C-IRMS/qMS) was developed. Thanks to the features of this system, enantiomeric excesses and target δ13C of the chiral and achiral components were evaluated in a single gas chromatographic run, allowing to reduce total time analysis, as well the consumption of electricity, solvents and samples. Moreover, due to the capability to baseline separate the enantiomeric couples, further considerations were done about the specific δ13C value of the target separated enantiomers. Dealing with the genuine lemon oils analysed, a different δ13C value was found between the enantiomers of the same chiral component, namely (-) and (+) of α and β-pinene, suggesting a different isotopic fractionation related to a specific biosynthetic pathway. This research aimed to evaluate the reasons behind this behaviour, paving the way to newer considerations in the field of authenticity assessment.

Recent times have witnessed an upsurge of interest in hemp and hemp-derived products, as driven by the scientific findings specific to the pharmacological properties of Cannabis sativa L. and its constituents. There has been evidence that the terpene profile, along with the cannabinoid content, produces in humans the effects associated with different strains, beyond fragrance perception. A great deal of effort has been put into developing analytical approaches to strengthen the scientific knowledge on cannabis essential oil composition and provide effective tools for ascertaining the authenticity of commercial cannabis samples. For this concern, enantio-selective-GC-C-IRMS has proven to be effective for assessing the ranges characteristic of the genuine samples and detecting any fraudulent additions. This research aimed at providing for the first time the enantiomeric and isotopic ratios of target terpenes in cannabis essential oils, obtained from microwave-assisted hydro-distillation from the fresh and dried inflorescences of different cannabis varieties. Implementing multidimensional gas chromatography separation was mandatory prior to detection, in order to obtain accurate δ13C values and enantiomeric data from completely separated peaks. For this purpose, a heart-cut method was developed, based on the coupling of an apolar first dimension column to a secondary chiral cyclodextrin-based stationary phase. Afterwards, the data gathered from enantio-selective-MDGC-C-IRMS/qMS analysis of a set of genuine samples were used to evaluate the quality of nineteen commercial cannabis essential oils purchased from local stores. Remarkably, the data in some cases evidenced enantiomeric ratios and δ13C values outside the typical ranges of genuine oils. Such findings suggest the usefulness of the method developed to ascertain the genuineness and quality of cannabis essential oils.