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  • 1
    Online Resource
    Online Resource
    Comparison of two methods for ginsenosides quantitation
    Wiley ; 2023
    In:  Journal of Separation Science Vol. 46, No. 6 ( 2023-03)
    Details
    In: Journal of Separation Science, Wiley, Vol. 46, No. 6 ( 2023-03)
    Abstract: The present study provides a comparison of two liquid chromatography–tandem mass spectrometry methods for ginsenosides analysis. The two methods have the same liquid chromatography separation procedure, and both use tandem mass spectrometry detection. However, one method uses multiple reaction monitoring transitions commonly recommended in the literature starting with [M + Na] + as the molecular ions and with detection of specific fragment ions from the molecules M, while the other is an original method using [M + Cs] + as molecular ions and Cs + as fragment ion. The method using [M + Cs] + as molecular ion has a very high sensitivity allowing the measurement of concentrations in the injecting solutions as low as 4 ng/ml with peaks at this concentration showing signal to noise ratio of 20 or higher. The procedures were utilized for the measurement of eight ginsenosides (Rb1, Rb2, Rc, Rd, Re, Rf (S), Rg1, and Rg2), although the method using [M + Cs] + has the potential for measuring other ginsenosides. As an application, the ginsenosides were measured in several types of ginseng root, several dietary supplements containing ginseng extracts, four energy drinks, and a sample of ashwagandha.
    Type of Medium: Online Resource
    ISSN: 1615-9306 , 1615-9314
    URL: Issue
    URL: Article
    DOI: 10.1002/jssc.v46.6
    DOI: 10.1002/jssc.202201063
    RVK:
    VA 5450
    Language: English
    Publisher: Wiley
    Publication Date: 2023
    detail.hit.zdb_id: 2037737-X
    detail.hit.zdb_id: 2047990-6
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  • 2
    Online Resource
    Online Resource
    Derivatization procedures and their analytical performances for HPLC determination in bioanalysis
    Wiley ; 2021
    In:  Biomedical Chromatography Vol. 35, No. 1 ( 2021-01)
    Details
    In: Biomedical Chromatography, Wiley, Vol. 35, No. 1 ( 2021-01)
    Abstract: Derivatization, or chemical structure modification, is often used in bioanalysis performed by liquid chromatography technique in order to enhance detectability or to improve the chromatographic performance for the target analytes. The derivatization process is discussed according to the analytical procedure used to achieve the reaction between the reagent and the target compounds (containing hydroxyl, thiol, amino, carbonyl and carboxyl as the main functional groups involved in derivatization). Important procedures for derivatization used in bioanalysis are in situ or based on extraction processes (liquid–liquid, solid‐phase and related techniques) applied to the biomatrix. In the review, chiral, isotope‐labeling, hydrophobicity‐tailored and post‐column derivatizations are also included, based on representative publications in the literature during the last two decades. Examples of derivatization reagents and brief reaction conditions are included, together with some bioanalytical applications and performances (chromatographic conditions, detection limit, stability and sample biomatrix).
    Type of Medium: Online Resource
    ISSN: 0269-3879 , 1099-0801
    URL: Issue
    URL: Article
    DOI: 10.1002/bmc.v35.1
    DOI: 10.1002/bmc.5008
    Language: English
    Publisher: Wiley
    Publication Date: 2021
    detail.hit.zdb_id: 1479945-5
    detail.hit.zdb_id: 632848-9
    SSG: 12
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  • 3
    Online Resource
    Online Resource
    Dependence of the distribution constant in liquid-liquid partition equilibria on the van der Waals molecular surface area : Liquid Chromatography
    Wiley ; 2013
    In:  Journal of Separation Science Vol. 36, No. 18 ( 2013-09), p. 2963-2978
    Details
    In: Journal of Separation Science, Wiley, Vol. 36, No. 18 ( 2013-09), p. 2963-2978
    Type of Medium: Online Resource
    ISSN: 1615-9306
    URL: Article
    DOI: 10.1002/jssc.201300330
    RVK:
    VA 5450
    Language: English
    Publisher: Wiley
    Publication Date: 2013
    detail.hit.zdb_id: 2037737-X
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  • 4
    Online Resource
    Online Resource
    Evaluation of the phase ratio for three C18 high performance liquid chromatographic columns
    Elsevier BV ; 2016
    In:  Journal of Chromatography A Vol. 1435 ( 2016-02), p. 85-91
    Details
    In: Journal of Chromatography A, Elsevier BV, Vol. 1435 ( 2016-02), p. 85-91
    Type of Medium: Online Resource
    ISSN: 0021-9673
    URL: Article
    DOI: 10.1016/j.chroma.2016.01.043
    RVK:
    VA 5050.A
    RVK:
    VG 7204
    RVK:
    IE 1100
    RVK:
    VA 1120
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2016
    detail.hit.zdb_id: 1171488-8
    SSG: 11
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  • 5
    Online Resource
    Online Resource
    Critical evaluation of several techniques for the analysis of phthalates and terephthalates: Application to liquids used in electronic cigarettes
    Elsevier BV ; 2018
    In:  Journal of Chromatography A Vol. 1540 ( 2018-03), p. 77-86
    Details
    In: Journal of Chromatography A, Elsevier BV, Vol. 1540 ( 2018-03), p. 77-86
    Type of Medium: Online Resource
    ISSN: 0021-9673
    URL: Article
    DOI: 10.1016/j.chroma.2018.02.001
    RVK:
    VA 5050.A
    RVK:
    VG 7204
    RVK:
    IE 1100
    RVK:
    VA 1120
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2018
    detail.hit.zdb_id: 1171488-8
    SSG: 11
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  • 6
    Online Resource
    Online Resource
    Dual Analysis of Triglycerides from Certain Common Lipids and Seed Extracts
    American Chemical Society (ACS) ; 2011
    In:  Journal of Agricultural and Food Chemistry Vol. 59, No. 6 ( 2011-03-23), p. 2137-2147
    Details
    In: Journal of Agricultural and Food Chemistry, American Chemical Society (ACS), Vol. 59, No. 6 ( 2011-03-23), p. 2137-2147
    Type of Medium: Online Resource
    ISSN: 0021-8561 , 1520-5118
    URL: Article
    DOI: 10.1021/jf104114p
    Language: English
    Publisher: American Chemical Society (ACS)
    Publication Date: 2011
    detail.hit.zdb_id: 1483109-0
    detail.hit.zdb_id: 241619-0
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  • 7
    Online Resource
    Online Resource
    Evaluation of the Content of Free Amino Acids in Tobacco by a New Liquid Chromatography-Tandem Mass Spectrometry Technique
    Walter de Gruyter GmbH ; 2015
    In:  Beiträge zur Tabakforschung International/Contributions to Tobacco Research Vol. 26, No. 7 ( 2015-9-1), p. 334-343
    Details
    In: Beiträge zur Tabakforschung International/Contributions to Tobacco Research, Walter de Gruyter GmbH, Vol. 26, No. 7 ( 2015-9-1), p. 334-343
    Abstract: La présente étude décrit une technique fiable d’analyse des acides aminés libres présents dans la feuille de tabac. Les teneurs en acides aminés sont d’importance dans le tabac puisqu’elles sont liées tant à la qualité du tabac qu’à la production potentielle, dans la fumée de tabac, de substances toxiques ayant des acides aminés précurseurs. D’autres techniques utilisées par le passé lors de l’analyse des acides aminés souffrent de diverses lacunes que la présente méthode évite. Cette nouvelle approche fait appel à la séparation en CLHP ainsi qu’à un spectromètre de masse en tandem (MS/MS) pour la détection sans passer par l’étape de dérivatisation pour préparer l’échantillon. La séparation est obtenue grâce à une colonne CLHP en phase inverse avec appariement d’ions, qui offre une excellente résolution chromatographique. La procédure de détection MS/MS offre une très bonne sensibilité et une identification positive des analytes. La procédure est pleinement validée et peut être utilisée pour l’analyse de 24 acides aminés. Elle a été appliquée à l’analyse chimique quantitative d’acides aminés provenant de 16 types de tabac, notamment du tabac jaune et du tabac Burley, certains tabacs cultivés aux USA et d’autres cultivés ailleurs, deux types de tabac d’Orient, du tabac de cigarettes de référence Kentucky 3R4F et une cigarette ordinaire vendue dans le commerce. Il a été démontré que l’analyse apporte des informations utiles quant à la variation de la teneur en acides aminés selon le type de tabac, la position des tiges de tabac et le lieu de culture des différents tabacs. [Beitr. Tabakforsch. Int. 26 (2015) 334-343]
    Type of Medium: Online Resource
    ISSN: 1612-9237
    URL: Article
    DOI: 10.1515/cttr-2015-0023
    Language: English
    Publisher: Walter de Gruyter GmbH
    Publication Date: 2015
    detail.hit.zdb_id: 2125737-1
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  • 8
    Online Resource
    Online Resource
    Analysis of Traces of Tobacco-Specific Nitrosamines (TSNAs) in USP Grade Nicotine, E-Liquids, and Particulate Phase Generated by the Electronic Smoking Devices
    Walter de Gruyter GmbH ; 2017
    In:  Beiträge zur Tabakforschung International/Contributions to Tobacco Research Vol. 27, No. 6 ( 2017-4-1), p. 86-96
    Details
    In: Beiträge zur Tabakforschung International/Contributions to Tobacco Research, Walter de Gruyter GmbH, Vol. 27, No. 6 ( 2017-4-1), p. 86-96
    Abstract: The present study describes the development of a liquid chromatography tandem mass spectrometry (LC-MS/MS) technique for the analysis of trace levels of four tobaccospecific nitrosamines (TSNAs): nitrosoanabasine (NAB), nitrosoanatabine (NAT), 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), and nitrosonornicotine (NNN). The technique can be applied for the analysis of TSNAs in USP grade nicotine. Nicotine used in e-liquids for the electronic smoking devices is typically obtained from tobacco plant materials ( Nicotiana tabacum, Nicotiana rustica ) and, although it is purified, it contains besides nicotine low levels of several contaminants such as minor alkaloids. It also contains traces of TSNAs. Analysis of TSNAs in USP grade nicotine is a challenging task since the analyzed samples contain about 10 +7 –10 +8 times more nicotine than individual TSNAs. Because the analyzed solutions cannot be diluted too much in order to keep the TSNAs level above the limit of quantitation (LOQ), even for apparently good chromatographic separations, the peak tailing of nicotine may generate interferences. The new method of analysis uses a Luna Omega 1.6 μm particles chromatographic column for separation and detection on a LC-MS/MS instrument with scheduled multiple reaction monitoring (Scheduled MRM). The levels of TSNAs in nicotine of USP purity from four commercial sources varied between 3 to 8 ng/g NAB, 4 to 20 ng/g NAT, 30 to 50 ng/g NNK, and 0.5 to 2 ng/g for NNN. Besides the analysis of TSNAs in nicotine, the technique has been applied successfully in the analysis of TSNAs in e-liquids and in particulate phase generated by the electronic smoking devices.
    Type of Medium: Online Resource
    ISSN: 1612-9237
    URL: Article
    DOI: 10.1515/cttr-2017-0009
    Language: English
    Publisher: Walter de Gruyter GmbH
    Publication Date: 2017
    detail.hit.zdb_id: 2125737-1
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  • 9
    Online Resource
    Online Resource
    Antioxidant Character and Levels of Polyphenols in Several Tea Samples
    American Chemical Society (ACS) ; 2021
    In:  ACS Omega Vol. 6, No. 15 ( 2021-04-20), p. 9982-9988
    Details
    In: ACS Omega, American Chemical Society (ACS), Vol. 6, No. 15 ( 2021-04-20), p. 9982-9988
    Type of Medium: Online Resource
    ISSN: 2470-1343 , 2470-1343
    URL: Article
    DOI: 10.1021/acsomega.0c05818
    Language: English
    Publisher: American Chemical Society (ACS)
    Publication Date: 2021
    detail.hit.zdb_id: 2861993-6
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  • 10
    Online Resource
    Online Resource
    Extraction from Moist Snuff with Artificial Saliva of Benzo[ a ]pyrene and Other Polycyclic Aromatic Hydrocarbons
    Walter de Gruyter GmbH ; 2019
    In:  Beiträge zur Tabakforschung International/Contributions to Tobacco Research Vol. 28, No. 5 ( 2019-05-01), p. 214-223
    Details
    In: Beiträge zur Tabakforschung International/Contributions to Tobacco Research, Walter de Gruyter GmbH, Vol. 28, No. 5 ( 2019-05-01), p. 214-223
    Abstract: The present study evaluated in vitro extractability of various polycyclic aromatic hydrocarbons (PAHs) from moist snuff, when the extracting agent was water or artificial saliva. The extraction was performed on nine brands of moist snuff samples that are commercially available and were purchased from the market in January 2018. The moist snuff brands were selected to represent brands with different tobacco cut size descriptors and flavors. For the measurement of PAHs, two different analytical methods were used, an HPLC (High Performance Liquid Chromatography) method for measuring only benzo[ a ]pyrene (BaP) and a GC/MS/MS (Gas Chromatography Tandem Mass Spectrometry) method for measuring 21 PAHs (including BaP). These methods were modifications of preexistent methods reported in the literature. The results for BaP indicated that by extracting 500 mg of freeze-dried moist snuff with 6 portions of 20 mL water (120 mL), or with 4 portions of 20 mL artificial saliva, followed by two portions of 20 mL water, the BaP remains close to 100% in the solid material and it is not detected in the extracting solution. PAHs with a molecular weight similar or heavier than BaP also showed no extractability. Lighter PAHs such as fluorene, phenanthrene, anthracene, and 5-methylanthracene showed a relatively good extractability. An intermediate group including fluoranthene, pyrene, and benz[ a ]anthracene showed some extractability in the conditions of this in vitro experiment. This study is not a substitute for clinical studies regarding PAH uptake in human users of moist snuff. However, the results indicate very limited bioavailability of BaP and heavier PAHs from moist snuff. Higher, but variable bioavailability was indicated for lighter PAHs. Important implications of these findings are that: 1) measurably different BaP content of two moist snuff products is unlikely to result in any meaningfully different consumer exposure to BaP; and 2) biomarkers for one PAH cannot necessarily be used as a reliable indicator of exposure to another PAH, particularly if the molecular weights of the precursor PAHs differ since their bioavailabilities can be very different. [Beitr. Tabakforsch. Int. 28 (2019) 214–223]
    Type of Medium: Online Resource
    ISSN: 1612-9237
    URL: Article
    DOI: 10.2478/cttr-2019-0002
    Language: English
    Publisher: Walter de Gruyter GmbH
    Publication Date: 2019
    detail.hit.zdb_id: 2125737-1
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