A method for determination of carbon dioxide specific radioactivity and concentration in blood, rumen fluid, and expired air

✍ Scribed by Richard W. Russell; Jerry W. Young

• Publisher: Elsevier Science
• Year: 1982
• Tongue: English
• Weight: 444 KB
• Volume: 124
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(82)90052-5

✦ Synopsis

A method is described for determining specific radioactivity and concentration of CO* in blood, rumen fluid, and expired air. The CO2 of blood and rumen fluid samples is liberated selectively by 1 M phosphate buffer (pH 5.8) containing 1 mM NaN, and 5 mM NaF. Liberated CO2 is quantitatively trapped in 0.3 N Ba(OH),, and amounts of CO2 are determined by titration of residual hydroxide ion. The resulting BaCO, is solubilized with 10% EDTA in 1 M Tris (pH 9), and radioactivity is determined by liquid scintillation. For quantitative determination of expired CO*, a measured fraction of expired air is bubbled through 0.3 N Ba(OH)r. The amount of trapped CO2 is determined by titrating residual hydroxide ion in an aliquot of trapping solution after BaCOr is precipitated by centrifugation. Radioactivity is determined by liquid scintillation spectrophotometry of ethanolamine carbamate after CO* is regenerated from BaCOa by addition of acid and quantitatively retrapped in ethanolamine.