Direct Semimicrodetermination of Oxygen in Organic Substances

Determination of Low Concentrations of Oxygen in Hydrogen

“…For amounts of water vapor in excess of about 50 liter-microns, measured in the 5500-liter-micron gage, the sample is circulated for 15 minutes. For is placed around trap T (Figure 1), and depending on the amount to be measured, the water is either evaporated through stopcock 8 (Figure 1) into the 5500-liter-micron gage, for 3 minutes, or distilled through stopcock 13 (Figure 2) into the 150-liter-micron gage, for 10 minutes, putting liquid nitrogen in the glass cup built into the gage for this purpose.…”

“…A sensitivity of 0.003% oxygen in hydrogen-nitrogen mixtures has been reported (34) for this method, but other work (13) suggests that a much higher sensitivity is possible.…”

“…Also suitable only for continuous analysis is a calorimetric method (7,20) in which oxygen is catalytically converted to water vapor and the temperature rise measured. If the gas is passed over carbon at 1120°C ., oxygen and its compounds are converted to carbon monoxide (13,36), which may be determined with the infrared gas analyzer or by conventional means.…”

Volumetric Analytical Methods for Organic Compounds

“…An improved apparatus and procedure are described to overcome interference due to hydrogen, permitting accurate and rapid analysis of materials of both low' and high oxygen content. The carbon monoxide formed is oxidized w'ith iodine pentoxide, and the resulting carbon dioxide is absorbed in a measured excess of 0.05W alkali hydroxide solution, which is back-titrated w'ith 0.025.V acid after precipitation of the carbonate with barium chloride (62).…”

Oxidation

“…The use of heavy oxygen in the analytical determination of oxygen in organic compounds has been described (88). Semimicrodetermination methods used at the U. S. Bureau of Mines for oxygen in organic compounds have been described (94). These methods were used in connection with studies of products obtained in the liquid fuels development program.…”