scholarly journals Differences in the Levels of the Selected Phytoestrogens and Stable Isotopes in Organic vs. Conventional Hops and Beer

Foods ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1839
Author(s):  
Jelena B. Golubović ◽  
Ester Heath ◽  
Iztok Jože Košir ◽  
Nives Ogrinc ◽  
Doris Potočnik ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Isotope Ratio ◽  
High Performance ◽  
Isotope Analysis ◽  
Isotope Ratio Mass Spectrometry ◽  
Supporting Evidence ◽  
Matched Pairs ◽  
13C Isotope ◽  
Significant Difference ◽  
Conventional Production

Xanthohumol (XN), isoxanthohumol (IX) and 8-prenylnaringenin (8-PN) are important prenylflavonoids present in hops with potential beneficial properties. In this study, we examined differences in the content of XN, IX and 8-PN in hops and beer produced under organic and conventional production regimes. A An ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) method for analysing XN, IX and 8-PN in hops and beer was developed and validated, with LOQ ranging from 0.5 to 10 ng/mL. Finally, we examined 15N/14N and 12C/13C isotope ratios in the hops and beer using isotope ratio mass spectrometry (IRMS). The results show no statistically significant difference in the content of the selected prenylflavonoids between organic and conventionally produced hops and beer—in the whole sample group, as well as between the matched pairs. Stable isotope analysis indicated that only δ15N values are statistically higher in organically produced hops and beer. However, the differentiation according to the type of production could not be made solely based on the δ15N signature, but it could be used to provide supporting evidence.

scholarly journals Use of compound specific δ¹³C stable isotope analysis for intact triacylglycerides using high temperature gas chromatography up to 430°C

2019 ◽  
Author(s):  
Paul Sutton ◽  
Mario Tuthorn ◽  
Jason Newton
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
High Temperature ◽  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Ratio ◽  
Isotope Analysis ◽  
Isotope Ratio Mass Spectrometry ◽  
13C Isotope ◽  
High Temperature Gas

Preliminary results from compound specific 13C isotope ratio mass spectrometry measurements of intact triacylglycerides in olive oil achieved by coupling high temperature gas chromatography with oven cycling up to 430C with IRMS

scholarly journals Use of compound specific δ¹³C stable isotope analysis for intact triacylglycerides using high temperature gas chromatography up to 430°C

2019 ◽  
Author(s):  
Paul Sutton ◽  
Mario Tuthorn ◽  
Jason Newton
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
High Temperature ◽  
Stable Isotope ◽  
Stable Isotope Analysis ◽  
Isotope Ratio ◽  
Isotope Analysis ◽  
Isotope Ratio Mass Spectrometry ◽  
13C Isotope ◽  
High Temperature Gas

Preliminary results from compound specific 13C isotope ratio mass spectrometry measurements of intact triacylglycerides in olive oil achieved by coupling high temperature gas chromatography with oven cycling up to 430C with IRMS

scholarly journals Measurement of δ18O and δ2H of water and ethanol in wine by Off-Axis Integrated Cavity Output Spectroscopy and Isotope Ratio Mass Spectrometry

2021 ◽  
Author(s):  
Xing Wang ◽  
Henk G. Jansen ◽  
Haico Duin ◽  
Harro A. J. Meijer
Keyword(s):  
Mass Spectrometry ◽  
Isotope Ratio ◽  
Isotope Analysis ◽  
Isotope Ratio Mass Spectrometry ◽  
Growth Conditions ◽  
The Other ◽  
H Nmr ◽  
Cavity Output ◽  
Pre Treatment ◽  
Output Laser

AbstractThere are two officially approved methods for stable isotope analysis for wine authentication. One describes δ18O measurements of the wine water using Isotope Ratio Mass Spectrometry (IRMS), and the other one uses Deuterium-Nuclear Magnetic Resonance (2H-NMR) to measure the deuterium of the wine ethanol. Recently, off-axis integrated cavity output (laser) spectroscopy (OA-ICOS) has become an easier alternative to quantify wine water isotopes, thanks to the spectral contaminant identifier (SCI). We utilized an OA-ICOS analyser with SCI to measure the δ18O and δ2H of water in 27 wine samples without any pre-treatment. The OA-ICOS results reveal a wealth of information about the growth conditions of the wines, which shows the advantages to extend the official δ18O wine water method by δ2H that is obtained easily from OA-ICOS. We also performed high-temperature pyrolysis and chromium reduction combined with IRMS measurements to illustrate the “whole wine” isotope ratios. The δ18O results of OA-ICOS and IRMS show non-significant differences, but the δ2H results of both methods differ much more. As the δ2H difference between these two methods is mainly caused by ethanol, we investigated the possibility to deduce deuterium of wine ethanol from this difference. The results present large uncertainties and deviate from the obtained 2H-NMR results. The deviation is caused by the other constituents in the wine, and the uncertainty is due to the limited precision of the SCI-based correction, which need to improve to obtain the 2H values of ethanol as alternative for the 2H-NMR method.

scholarly journals On the interference of Kr during carbon isotope analysis of methane using continuous-flow combustion–isotope ratio mass spectrometry

2013 ◽  
Vol 6 (5) ◽  
pp. 1425-1445 ◽  
Author(s):  
J. Schmitt ◽  
B. Seth ◽  
M. Bock ◽  
C. van der Veen ◽  
L. Möller ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Carbon Isotope ◽  
Isotope Ratio ◽  
Stable Carbon Isotope ◽  
Isotope Analysis ◽  
Isotope Ratio Mass Spectrometry ◽  
Mass Spectrometric Measurement ◽  
Broad Signal ◽  
Carbon Isotope Analysis ◽  
Singly Charged

Abstract. Stable carbon isotope analysis of methane (δ13C of CH4) on atmospheric samples is one key method to constrain the current and past atmospheric CH4 budget. A frequently applied measurement technique is gas chromatography (GC) isotope ratio mass spectrometry (IRMS) coupled to a combustion-preconcentration unit. This report shows that the atmospheric trace gas krypton (Kr) can severely interfere during the mass spectrometric measurement, leading to significant biases in δ13C of CH4, if krypton is not sufficiently separated during the analysis. According to our experiments, the krypton interference is likely composed of two individual effects, with the lateral tailing of the doubly charged 86Kr peak affecting the neighbouring m/z 44 and partially the m/z 45 Faraday cups. Additionally, a broad signal affecting m/z 45 and especially m/z 46 is assumed to result from scattered ions of singly charged krypton. The introduced bias in the measured isotope ratios is dependent on the chromatographic separation, the krypton-to-CH4 mixing ratio in the sample, the focusing of the mass spectrometer as well as the detector configuration and can amount to up to several per mil in δ13C. Apart from technical solutions to avoid this interference, we present correction routines to a posteriori remove the bias.

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