Correction.  Tube Cracker for Opening Glass-Sealed Ampoules under Vacuum

Marais, Deon; Hayes, John M.

doi:10.1021/ac50009a057

Cited by 7 publications

(5 citation statements)

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“…From this we deduced, that a fractionating adsorption process occurs on the fresh glass surface. Although the tube cracker technique is well established for many decades (Des Marais and Hayes, 1976;Caldwell et al, 1983), this method is generally applied for dual inlet-Multiport measurements with CO 2 amounts a factor of 100 larger than in our case.…”

Section: Humidifiermentioning

confidence: 94%

A sublimation technique for high-precision measurements of δ13CO2 and mixing ratios of CO2 and N2O from air trapped in ice cores

2011

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Abstract. In order to provide high precision stable carbon isotope ratios (δ 13 CO 2 or δ 13 C of CO 2 ) from small bubbly, partially and fully clathrated ice core samples we developed a new method based on sublimation coupled to gas chromatography-isotope ratio mass spectrometry (GC-IRMS). In a first step the trapped air is quantitatively released from ∼30 g of ice and CO 2 together with N 2 O are separated from the bulk air components and stored in a miniature glass tube. In an off-line step, the extracted sample is introduced into a helium carrier flow using a minimised tube cracker device. Prior to measurement, N 2 O and organic sample contaminants are gas chromatographically separated from CO 2 . Pulses of a CO 2 /N 2 O mixture are admitted to the tube cracker and follow the path of the sample through the system. This allows an identical treatment and comparison of sample and standard peaks. The ability of the method to reproduce δ 13 C from bubble and clathrate ice is verified on different ice cores. We achieve reproducibilities for bubble ice between 0.05 ‰ and 0.07 ‰ and for clathrate ice between 0.05 ‰ and 0.09 ‰ (dependent on the ice core used). A comparison of our data with measurements on bubble ice from the same ice core but using a mechanical extraction device shows no significant systematic offset. In addition to δ 13 C, the CO 2 and N 2 O mixing ratios can be volumetrically derived with a precision of 2 ppmv and 8 ppbv, respectively.

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Section: Humidifiermentioning

confidence: 94%

A sublimation technique for high-precision measurements of δ13CO2 and mixing ratios of CO2 and N2O from air trapped in ice cores

2011

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“…The cellulose sample (20 mg), copper oxide, and a piece of silver foil were loaded into quartz tubes, the tubes evacuated to less than 10 Ϫ2 Torr, sealed off with an oxy-butane torch, and heated for a minimum of 4 h at 800°C (Sofer, 1980;Sealy, 1986). After cooling, the tubes were removed from the furnace, scored in the middle to ensure easy cracking and to prevent splitting, and inserted into a cracker of the type described by Desmarais and Hayes (1976). The combustion process produces CO 2 , nitrogen, and water vapor which are separated from each other on a cryogenic gas separation line into which the tube was inserted (Sealy, 1986).…”

Section: Methodsmentioning

confidence: 99%

Declining Trend in the¹³C/¹²C Ratio of Atmospheric Carbon Dioxide from Tree Rings of South AfricanWiddringtonia cedarbergensis

February

Stock

1999

Quat. res.

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Stable carbon isotope chronologies using tree ring wood cellulose have proved useful for developing hypotheses on climate and environment change. However, within both the Southern Hemisphere and Africa there has been very little tree-ring-based isotope research. Here we report the first high-resolution (annual) 13C/12C chronology for both Africa and the Southern Hemisphere. The 77-yr stable carbon isotope chronology was developed from six Widdringtonia cedarbergensis trees from a site in the Cedarberg Mountains, Western Cape Province, South Africa. The results indicate that 13C/12C ratios are not different from 1900 to 1949. After 1949, however, values become significantly more negative to 1977. The isotopic record from the pooled trees at the Die Bos site does not correlate with rainfall. This correlation is not significant even when the Widdringtonia stable carbon isotope record is de-trended for the anthropogenic CO2 contribution. The Widdringtonia record does, however, correlate significantly with atmospheric 13C/12C CO2 values derived from ice core data, tree ring 13C/12C chronologies from the Northern Hemisphere, and recent Southern Hemisphere records.

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“…Milk, feed and tissue samples were combusted to CO2 in evacuated, sealed quartz tubes (Boutton et al, 1983). After combustion, sample tubes were opened under vacuum (Des Marais and Hayes, 1976), the CO2 was isolated and purified by cryogenic distillation and the volume of CO2 produced was measured manometrically for calculation of percentage carbon. The CO2 then was transferred into 20-cc vacutainers and analyzed for 13C/12C on an automated isotope ratio mass spectrometer 7 (Schoeller and Klein, 1979).…”

Section: Sample Preparation and Mass Spectrometrymentioning

confidence: 99%

Carbon Kinetics of Milk Formation in Holstein Cows in Late Lactation

Boutton¹,

Tyrrell²,

Patterson³

et al. 1988

Journal of Animal Science

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Carbon transfer to milk in Holstein cows in late lactation was measured by introducing changes in the natural stable carbon isotope composition of the feed. Six Holstein cows in mid-lactation were placed on a diet naturally low in 13C (-25.0% vs Pee Dee belemnite [PDB] an international carbon isotope standard), based on alfalfa-barley, and six others were placed on a diet naturally enriched in 13C (-11.5% vs PDB), based on corn. After a 7-wk equilibration period on these diets, three cows were switched from alfalfa-barley to corn, and three were switched from corn to alfalfa-barley. The three other cows in each group served as controls. 13C/12C ratios were measured in daily morning milk samples during the week before and for 6 wk after the changes in diet. After the diets had been switched, milk isotope ratios rapidly approached the isotopic composition of the new diet, indicating rapid transfer of dietary carbon into milk. The data were consistent with a model whereby milk was synthesized from a single precursor pool that responded rapidly to dietary perturbation. The milk precursor pool had a half-life of approximately .9 d and had a mass of approximately 7 kg of carbon, which was renewed daily by the entry of 5 kg of digestible dietary carbon.

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Correction. Tube Cracker for Opening Glass-Sealed Ampoules under Vacuum

Cited by 7 publications

References 0 publications

A sublimation technique for high-precision measurements of δ<sup>13</sup>CO<sub>2</sub> and mixing ratios of CO<sub>2</sub> and N<sub>2</sub>O from air trapped in ice cores

A sublimation technique for high-precision measurements of δ<sup>13</sup>CO<sub>2</sub> and mixing ratios of CO<sub>2</sub> and N<sub>2</sub>O from air trapped in ice cores

Declining Trend in the¹³C/¹²C Ratio of Atmospheric Carbon Dioxide from Tree Rings of South AfricanWiddringtonia cedarbergensis

Carbon Kinetics of Milk Formation in Holstein Cows in Late Lactation

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Correction. Tube Cracker for Opening Glass-Sealed Ampoules under Vacuum

Cited by 7 publications

References 0 publications

A sublimation technique for high-precision measurements of δ&lt;sup&gt;13&lt;/sup&gt;CO&lt;sub&gt;2&lt;/sub&gt; and mixing ratios of CO&lt;sub&gt;2&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt;O from air trapped in ice cores

A sublimation technique for high-precision measurements of δ&lt;sup&gt;13&lt;/sup&gt;CO&lt;sub&gt;2&lt;/sub&gt; and mixing ratios of CO&lt;sub&gt;2&lt;/sub&gt; and N&lt;sub&gt;2&lt;/sub&gt;O from air trapped in ice cores

Declining Trend in the13C/12C Ratio of Atmospheric Carbon Dioxide from Tree Rings of South AfricanWiddringtonia cedarbergensis

Carbon Kinetics of Milk Formation in Holstein Cows in Late Lactation

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Product

Resources

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A sublimation technique for high-precision measurements of δ<sup>13</sup>CO<sub>2</sub> and mixing ratios of CO<sub>2</sub> and N<sub>2</sub>O from air trapped in ice cores

A sublimation technique for high-precision measurements of δ<sup>13</sup>CO<sub>2</sub> and mixing ratios of CO<sub>2</sub> and N<sub>2</sub>O from air trapped in ice cores

Declining Trend in the¹³C/¹²C Ratio of Atmospheric Carbon Dioxide from Tree Rings of South AfricanWiddringtonia cedarbergensis