Determination of the concentration of carbon dioxide gas by a laser method

1979 ◽  
Vol 31 (4) ◽  
pp. 1236-1239 ◽  
Author(s):  
N. A. Belov ◽  
A. K. Koval' ◽  
V. D. Mironov ◽  
A. I. Popov ◽  
E. D. Protsenko
Keyword(s):  
Carbon Dioxide ◽  
Laser Method ◽  
Carbon Dioxide Gas

Determination of carbonates in detergents by a carbon dioxide gas selective electrode

1985 ◽  
Vol 57 (8) ◽  
pp. 1523-1526 ◽  
Author(s):  
Satoshi. Takano ◽  
Yukihiro. Kondoh ◽  
Hiroshi. Ohotsuka
Keyword(s):  
Carbon Dioxide ◽  
Selective Electrode ◽  
Carbon Dioxide Gas

Automated Enzymatic Determination of L-Lysine in Grain

1974 ◽  
Vol 57 (5) ◽  
pp. 1098-1103 ◽  
Author(s):  
Larry L Wall ◽  
Charles W Gehrke
Keyword(s):  
Carbon Dioxide ◽  
Free Water ◽  
Dialysis Membrane ◽  
Standard Curve ◽  
Carbon Dioxide Gas ◽  
Automated Method ◽  
Enzymatic Determination ◽  
Exchange Data ◽  
Good Agreement

Abstract An accurate and precise automated method has been developed for the determination of lysine in grain hydrolysates. The enzyme L-lysine decarboxylase specifically catalyzes removal of the carboxyl group from L-lysine, producing an amine and carbon dioxide. This reaction has been automated. The carbon dioxide produced was selectively dialyzed into a stream of carbonate with phenolphthalein by a dialysis block containing a carbon dioxide gas dialysis membrane. Ground samples of grain (250 mg) were hydrolyzed 20 hr in 25 ml 6N HC1 at 110°C Aliquots were evaporated to dryness under nitrogen with low heat. The samples were redissolved in carbon dioxide-free water and the enzyme was suspended in pH 6.5 phosphate buffer. Analyses were made at 30/hr with a sample-to-wash ratio of 4:1. A standard curve with a range of 0 to 90 ppm lysine was expanded to full scale on the recorder. From the comparative height of each sample peak vs. the standard curve, the per cent lysine in the original sample can be calculated. Repeated analyses on 15 samples, 5 each of corn, mungbeans, and soybeans, by the automated method showed that the precision was good, and the results were in good agreement with classical ion exchange data. The automated method for lysine in corn has been used in our laboratory to analyze 1500–2000 corn samples each year for the last 5 years.

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