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JEOL Resources

Documentation in support of your JEOL product.

Flavones and Flavor Components in Two Basil Leaf Chemotypes

The chemical composition of herbs and spices can vary dramatically between different species and different growing conditions. Herbs grown under different conditions that have different essential oil compositions are referred to as chemotypes. Basil is an herb that has widely varying chemotypes. The difference between basil leaves from two different sources was easily observed by using DART. A leaf from a basil plant purchased at a grocery store was compared with a leaf from a Vietnamese restaurant. A small particle from each leaf was analyzed placed in front of the DART source. Mass spectra were obtained within seconds. Elemental compositions were confirmed by exact masses and accurate isotopic abundance measurements.

Direct Analysis in Real Time (DART®) Mass Spectrometry

Mass Spectrometry (MS) is one of the fastest-growing areas in analytical instrumentation. The use of mass spectrometry in support of synthetic, organic, and pharmaceutical chemistry is well established. Mass spectrometry is also used in materials science, environmental research, and forensic chemistry. It has also evolved into one of the core methods used in biotechnology. However, currently available ion sources place extreme restrictions on the speed and convenience of sample analysis by mass spectrometry. Here we report a method for using mass spectrometry to instantaneously analyze gases, liquids, and solids in open air at ground potential under ambient conditions. Traditional ion sources used in mass spectrometry require the introduction of samples into a high vacuum system.

What Is the Opposite of Pandora’s Box? Direct Analysis, Ambient Ionization, and a New Generation of Atmospheric Pressure Ion Sources

The introduction of DART and DESI sources approximately seven years ago led to the development of a new series of atmospheric pressure ion sources referred to as “ambient ionization” sources. These fall into two major categories: spray techniques like DESI or plasma techniques like DART. The selectivity of “direct ionization,” meaning analysis without chromatography and with little or no sample preparation, depends on the mass spectrometer selectivity. Although high resolution and tandem mass spectrometry are valuable tools, rapid and simple sample preparation methods can improve the utility of ambient ionization methods. The concept of ambient ionization has led to the realization that there are many more ways to form ions than might be expected. An interesting example is the use of a flint-and-steel spark source to generate ions from compounds such as phenolphthalein and Gramicidin S.

Rapid detection of fentanyl, fentanyl analogues, and opioids for on-site or laboratory based drug seizure screening using thermal desorption DART-MS and ion mobility spectrometry

Fentanyl and fentanyl analogues represent a current and emerging threat in the United States as pure illicit narcotics and in mixtures with heroin. Because of their extreme potency, methods to safely and rapidly detect these compounds are of high interest. This work investigates the use of thermal desorption direct analysis in real time mass spectrometry (TD-DART-MS) and ion mobility spectrometry (IMS) as tools for the rapid and sensitive (nanogram to picograms) detection of fentanyl, 16 fentanyl analogues, and five additional opioids. Competitive ionization studies highlight that detection of these compounds in the presence of heroin is readily achievable, down to 0.1% fentanyl by mass with TD-DART-MS. With IMS, detection of nanogram levels of fentanyl in a binary fentanyl and heroin mixture is possible but can be complicated by decreased resolution in certain commercial instrument models. Modifications to the alarm windows can be used to ensure detection of fentanyl in binary mixtures. Additionally, three complex background matrices (fingerprint residue, dirt, and plasticizers) are shown to have a minimal effect of the detection of these compounds. Wipe sampling of the exterior of bags of questioned powders is shown to be a safe alternative method for field screening and identification, removing the need to handle potentially lethal amounts of material.

Mechanosensitivity below Ground: Touch-Sensitive Smell-Producing Roots in the Shy Plant Mimosa pudica

The roots of the shy plant Mimosa pudica emit a cocktail of small organic and inorganic sulfur compounds and reactive intermediates into the environment, including SO2, methanesulfinic acid, pyruvic acid, lactic acid, ethanesulfinic acid, propanesulfenic acid, 2-aminothiophenol, S-propyl propane 1-thiosulfinate, phenothiazine, and thioformaldehyde, an elusive and highly unstable compound that, to our knowledge, has never before been reported to be emitted by a plant. When soil around the roots is dislodged or when seedling roots are touched, an odor is detected. The perceived odor corresponds to the emission of higher amounts of propanesulfenic acid, 2-aminothiophenol, S-propyl propane 1-thiosulfinate, and phenothiazine. The mechanosensitivity response is selective. Whereas touching the roots with soil or human skin resulted in odor detection, agitating the roots with other materials such as glass did not induce a similar response. Light and electron microscopy studies of the roots revealed the presence of microscopic sac-like root protuberances. Elemental analysis of these projections by energy-dispersive x-ray spectroscopy revealed them to contain higher levels of K+ and Cl− compared with the surrounding tissue. Exposing the protuberances to stimuli that caused odor emission resulted in reductions in the levels of K+ and Cl− in the touched area. The mechanistic implications of the variety of sulfur compounds observed vis-à-vis the pathways for their formation are discussed.

Identification of selected CITES-protected Araucariaceae using DART TOFMS

Determining the species source of logs and planks suspected of being Araucaria araucana (Molina) K.Koch (CITES Appendix I) using traditional wood anatomy has been difficult, because its anatomical features are not diagnostic. Additionally, anatomical studies of Araucaria angustifolia (Bertol.) Kuntze, Araucaria heterophylla (Salisb.) Franco, Agathis australis (D.Don) Lindl., and Wollemia nobilis W.G.Jones, K.D.Hill & J.M.Allen have reported that these taxa have similar and indistinguishable anatomical characters from A. araucana. Transnational shipments of illegal timber obscure their geographic provenance, and therefore identification using wood anatomy alone is insufficient in a criminal proceeding. In this study we examine the macroscopic appearance of selected members of the Araucariaceae and investigate whether analysis of heartwood chemotypes using Direct Analysis in Real Time (DART) Time-of-Flight Mass Spectrometry (TOFMS) is useful for making species determinations. DART TOFMS data were collected from 5 species (n =75 spectra). The spectra were analyzsed statistically using supervised and unsupervised classification algorithms. Results indicate that A. araucana can be distinguished from the look-alike taxa. Another statistical inference of the data suggests that Wollemia nobilis is more similar and within the same clade as Agathis australis. We conclude that DART TOFMS spectra can help in making species determination of the Araucariaceae even when the geographic provenance is unknown.

Elderberry Flavonoids Bind to and Prevent H1N1 Infection in-vitro

A ionization technique in mass spectrometry called Direct Analysis in Real Time Mass Spectrometry (DART TOF-MS) coupled with a Direct Binding Assay was used to identify and characterize anti-viral components of an elderberry fruit (Sambucus nigra L.) extract without either derivatization or separation by standard chromatographic techniques. The elderberry extract inhibited Human Influenza A (H1N1) infection in vitro with an IC(50) value of 252+/-34 microg/mL. The Direct Binding Assay established that flavonoids from the elderberry extract bind to H1N1 virions and, when bound, block the ability of the viruses to infect host cells. Two compounds were identified, 5,7,3',4'-tetra-O-methylquercetin (1) and 5,7-dihydroxy-4-oxo-2-(3,4,5-trihydroxyphenyl)chroman-3-yl-3,4,5-trihydroxycyclohexanecarboxylate (2), as H1N1-bound chemical species. Compound 1 and dihydromyricetin (3), the corresponding 3-hydroxyflavonone of 2, were synthesized and shown to inhibit H1N1 infection in vitro by binding to H1N1 virions, blocking host cell entry and/or recognition. Compound 1 gave an IC(50) of 0.13 microg/mL (0.36 microM) for H1N1 infection inhibition, while dihydromyricetin (3) achieved an IC(50) of 2.8 microg/mL (8.7 microM). The H1N1 inhibition activities of the elderberry flavonoids compare favorably to the known anti-influenza activities of Oseltamivir (Tamiflu; 0.32 microM) and Amantadine (27 microM).

Elemental Composition Determinations Using the Abundant Isotope

Elemental compositions are commonly determined from the exact m/z of the monoisotopic peak, which is often the lightest isotope. However, the lightest isotope peak is often weak or absent and the monoisotopic peak can be difficult to identify for organometallics, polyhalogenated compounds, or large molecules. An alternative approach using the abundant isotope for elemental composition determinations is presented here.

Direct, Real-Time Mass Spectrometry Analysis of Cinnamon

To ensure food safety, rapid detection of adulterated and counterfeit food products is critical. One such method, Direct Analysis in Real Time-Mass Spectrometry (DART-MS) (IonSense, Saugus, Mass.), quickly screens and analyzes a wide array of samples for mass spectral information and does not require sample preparation. As an example, several recent studies detail the analysis of cinnamon, mostly using chromatographic methods. High concentrations of coumarin in cinnamon have prompted numerous investigations as well, as its presence is suspected of being harmful. All of these studies require sample derivatization and long analysis times. In the current study, DART-MS was used to analyze cinnamon and detect the presence of coumarin.

Direct analysis in real time mass spectrometry with collision-induced dissociation for structural analysis of synthetic cannabinoids

DART-MS spectra were acquired under CID conditions to rapidly differentiate among  five synthetic cannabinoids contained within  ’herbal’ products purchased locally in New York State (USA). The spectra exhibited [M+H]+ ions and product ions unique to each cannabinoid that corresponded to major structural features. Five different cannabinoid analogs, alone and as mixtures of at least two cannabinoids, were identified in six herbal products and differentiated by their CID product ion patterns.

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Corona - Glow Discharge (DART Ion Source)

February 22, 2020
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