Determination of the Optimum Conditions for Boric Acid Extraction with Carbon Dioxide Gas in Aqueous Media from Colemanite Containing Arsenic

2000 ◽  
Vol 39 (2) ◽  
pp. 488-493 ◽  
Author(s):  
Osman Nuri Ata ◽  
Sabri Çolak ◽  
Mehmet Çopur ◽  
Cafer Çelik
Keyword(s):  
Carbon Dioxide ◽  
Boric Acid ◽  
Aqueous Media ◽  
Acid Extraction ◽  
Optimum Conditions ◽  
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

Determination of oxalate by continuons analysis using photochemical oxidation by iron(III) and a CO2 electrode detector

1978 ◽  
Vol 56 (18) ◽  
pp. 2452-2458 ◽  
Author(s):  
Jean Margaret Cooley ◽  
Byron Kratochvil
Keyword(s):  
Carbon Dioxide ◽  
Calibration Curve ◽  
Theoretical Study ◽  
Ionic Species ◽  
Photochemical Oxidation ◽  
Optimum Conditions ◽  
Linear Calibration ◽  
Ion Concentrations ◽  
Co2 Electrode

Oxalate concentrations were measured by photochemical oxidation with iron(III) to carbon dioxide. Technicon AutoAnalyzer components were used to automate the sampling and mixing steps, and the carbon dioxide produced in the radiation step was measured with a CO2 electrode. Variables in the System were evaluated and the optimum conditions identified. A theoretical study was made of the effect on ionic species concentrations of variations in iron(III), acid, and counter ion concentrations. A linear calibration curve could be obtained for oxalate concentrations in the range of 2 × 10−4 to 0.02 M; by modifying conditions linearity could be achieved at both higher and lower concentration ranges. Several other acids are partially oxidized under optimum conditions for oxalate. Tartrate, citrate, and malonate introduce errors of 2% or less at concentrations equivalent to oxalate; malate and pyruvate cause errors on the order of 10%. Several small carboxylic acids were found to interfere with the CO2 electrode.

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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