RESUMO
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.
Assuntos
Cannabis , Óleos Voláteis , Cannabis/química , Isótopos de Carbono , Cromatografia Gasosa/métodos , Cromatografia Gasosa-Espectrometria de Massas/métodos , Humanos , Óleos Voláteis/análise , Terpenos/análiseRESUMO
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.
Assuntos
Cromatografia Gasosa-Espectrometria de Massas , Vitis , Vinho , Vitis/química , Vinho/análise , Estereoisomerismo , Cromatografia Gasosa-Espectrometria de Massas/métodos , Isótopos de Carbono/análise , Monoterpenos/análise , Monoterpenos/química , Frutas/químicaRESUMO
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 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.
Assuntos
Cannabis , Destilação , Flores , Cromatografia Gasosa-Espectrometria de Massas , Micro-Ondas , Óleos Voláteis , Cannabis/química , Destilação/métodos , Flores/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Óleos Voláteis/análise , Óleos Voláteis/química , Terpenos/análise , Dronabinol/análise , Cromatografia Gasosa/métodosRESUMO
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 enantioselective 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 ß-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.
RESUMO
Polyhydroxyalkanoate (PHA), a family of biodegradable and renewable biopolymers that could potentially play a significant role in bioeconomy. In this study we investigated the potential of date waste (DW) biomass as feedstock to produce PHA by the halophilic archaeon Haloferax mediterranei. The concentration of essential trace elements for H. mediterranei cells during growth and PHA biopolymer accumulation was optimized. A maximum cell dry mass of (CDM) (12.8 g L-1) and PHA concentration of (3.20 g L-1) were achieved in DW extract media that was not supplemented with trace elements, indicating that DW is a promising source for trace elements. The cultivation was scaled-up to fed-batch bioreactor fermentations under non-sterile conditions and resulted in CDM and PHA content of 18.0 g L-1 and 25%, respectively. The produced PHA was confirmed to be poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) with high 3-hydroxyvalerate (3 HV) content of 18.0 mol%. This 3 HV molar percent was achieved without the addition of expensive precursors. The PHBV is of high molecular weight (746.0 kDa) and narrow polydispersity (PDI = 1.5), and displayed reduced melting at 148.1 °C. The X-ray diffraction (XRD) analysis showed that the PHBV has amorphous nature which increases the degradation rates and workability of the biopolymer. The isotopic ratio 13C/12C (δ 13C) for PHBV was found to be - 19.1, which indicated that H. mediterranei prefers lighter bonds to break and uses the lighter atoms for the biosynthesis of PHBV.
Assuntos
Haloferax mediterranei , Phoeniceae , Poli-Hidroxialcanoatos , Fermentação , Hidroxibutiratos , PoliésteresRESUMO
Food traceability is increasingly relevant with respect to safety, quality and typicality issues. Lemon fruits grown in a typical lemon-growing area of southern Italy (Siracusa), have been awarded the PGI (Protected Geographical Indication) recognition as 'Limone di Siracusa'. Due to its peculiarity, consumers have an increasing interest about this product. The detection of potential fraud could be improved by using the tools linking the composition of this production to its typical features. This study used a wide range of analytical techniques, including conventional techniques and analytical approaches, such as spectral (NIR spectra), multi-elemental (Fe, Zn, Mn, Cu, Li, Sr) and isotopic ((13)C/(12)C, (18)O/(16)O) marker investigations, joined with multivariate statistical analysis, such as PLS-DA (Partial Least Squares Discriminant Analysis) and LDA (Linear Discriminant Analysis), to implement a traceability system to verify the authenticity of 'Limone di Siracusa' production. The results demonstrated a very good geographical discrimination rate.
Assuntos
Citrus/química , Análise Discriminante , Frutas/química , Itália , Análise dos Mínimos Quadrados , Espectroscopia de Luz Próxima ao InfravermelhoRESUMO
The contamination of commonly used supplements by unknown steroids as well as their metabolites (parent compounds) become a challenge for the analytical laboratories. Although the determination of steroids profile is not trivial because of the complex matrix and low concentration of single compound, one of the most difficult current problem is to distinguish, during analytical procedure, endogenous androgens such as testosterone, dehydrotestosterone or dehydroepiandrosterone from their synthetic equivalents. The aim of this work was to develop and validate an analytical procedure for determination of the steroid profile in human urine by gas chromatography-combustion-isotope ratio mass spectrometry (GC/C/IRMS) toward distinguishing between endogenous and exogenous steroids. Beside the optimization of the experimental parameters for gas chromatography separation and mass spectrometry, attention was focused on urine sample preparation. Using an optimized sample preparation protocol it was possible to achieve better chromatographic resolutions and better sensitivity enabling the determination of 5 steroids, androsterone, etiocholanolone, testosterone, 5-androstandiol, 11-hydroxyandrdostane, pregnandiol, with the expanded uncertainty (k=2) below 1. This enable to evaluate the significant shift of the δ(13)C/(12)C [] values for each of examined steroids (excluding ERC). The analytical protocol described in this work was successfully used for the confirmation of positive founding urine by evaluation T/E ratio after GC/C/IRMS analysis.