scholarly journals Stable Carbon Isotope Analysis of Individual Sterols in Sediment Samples by Gas Chromatography/Isotope Ratio Mass Spectrometry.

1997 ◽  
Vol 45 (6) ◽  
pp. 641-648 ◽  
Author(s):  
Kohei MATSUMOTO ◽  
Keita YAMADA ◽  
Hiroshi NARAOKA ◽  
Ryoshi ISHIWATARI
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Carbon Isotope ◽  
Isotope Ratio ◽  
Stable Carbon Isotope ◽  
Isotope Analysis ◽  
Isotope Ratio Mass Spectrometry ◽  
Stable Carbon ◽  
Sediment Samples ◽  
Stable Carbon Isotope Analysis

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.

scholarly journals Method for determination of stable carbon isotope ratio of methylnitrophenols in atmospheric particulate matter

2011 ◽  
Vol 4 (11) ◽  
pp. 2453-2464 ◽  
Author(s):  
S. Moukhtar ◽  
M. Saccon ◽  
A. Kornilova ◽  
S. Irei ◽  
L. Huang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Particulate Matter ◽  
Stable Isotope ◽  
Carbon Isotope ◽  
Isotope Ratio ◽  
Stable Carbon Isotope ◽  
Atmospheric Particulate Matter ◽  
Stable Carbon ◽  
Atmospheric Particulate

Abstract. A technique for the measurement of the stable isotope ratio of methylnitrophenols in atmospheric particulate matter is presented. Atmospheric samples from rural and suburban areas were collected for evaluation of the procedure. Particulate matter was collected on quartz fibre filters using dichotomous high volume air samplers. Methylnitrophenols were extracted from the filters using acetonitrile. The sample was then purified using a combination of high-performance liquid chromatography and solid phase extraction. The final solution was then divided into two aliquots. To one aliquot, a derivatising agent, Bis(trimethylsilyl)trifluoroacetamide, was added for Gas Chromatography-Mass Spectrometry analysis. The second half of the sample was stored in a refrigerator. For samples with concentrations exceeding 1 ng μl−1, the second half of the sample was used for measurement of stable carbon isotope ratios by Gas Chromatography-Isotope Ratio Mass Spectrometry. The procedure described in this paper provides a method for the analysis of methylnitrophenols in atmospheric particulate matter at concentrations as low as 0.3 pg m−3 and for stable isotope ratios with an accuracy of better than ±0.5‰ for concentrations exceeding 100 pg m−3. In all atmospheric particulate matter samples analysed, 2-methyl-4-nitrophenol was found to be the most abundant methylnitrophenol, with concentrations ranging from the low pg m−3 range in rural areas to more than 200 pg m−3 in some samples from a suburban location.

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