Determination of Oxygen in Organic Materials by Modified Sch¨tze-Unterzaucher Method

Abstract

The SchGtze-Unterzaucher method was investigated formed from the hydrocarbon samples was gaseous hl-drobecause high results were obtained when certain gen and not hydrocarbons of low molecular weight. The sulfur lots of iodine pentoxide were used in the determina-compounds were largely converted t o hydrogen sulfide when tion of oxygen; analysis of hydrocarbon samples sufficient hydrogen was present in the sample, but where a indicated oxygen contents as high as 2.5%. Data deficiency of hydrogen existed there was an increasing tendency indicate that this anomaly is caused by liberation of for the formation of carbon disulfide. Carbonyl sulfide was extraneous iodine from the iodine pentoxide through produced in much smaller quantities. Nitrogen where present the partial reaction of the oxidant and the hydrogen was converted to hydrogen cyanide. Small quantities of hyformed by the pyrolysis of the sample. A gravi-drogen cyanide were also obtained from the samples conmetric procedure precludes interference due to ex-taining no nitrogen, an indication that the sweeping gas had traneous iodine. The iodine is retained in an absorpprobably reacted with the hot carbon to a limited extent. Ortion tube containing crystals of sodium thiosulfate ganic chlorine compounds formed hydrogen chloride. and suitable drying agents. The carbon dioxide is $]though the data presented are not extensive enough to give weighed by conven tional means in a Pregl micro ab-a satisfactory indication of exactly what happens in the reaction sorption tube. Improvements in apparatus and ex-tube, the results give a better understanding of why there were periences with both methods are described.some interferences in the volumetric method of Unterzaucher, Graham and Winmill (5), who determined carbon monoxide in

Similarities in Recalcitrant Structures of Industrial Non‐Kraft and Kraft Lignin

“…The S content was determined by flask combustion and subsequent titration. The O content was determined gravimetrically by pyrolysis at 1200 °C (Unterzaucher method). The concentration of other elements was determined by proton‐induced X‐ray emission (PIXE) analysis by Elemental Analysis Inc. (Lexington, KY, elementalanalysis.com).…”

Determination of oxygen in organic substances by reaction-frontal gas chromatography

“…With regards to (i), the pyrolysis of C, , O compounds in an empty pyrolytic tube (13) resulted in C6H6, C02 or CO (and/or a mixture of both), CH4, H2, H20 (saccharides), and traces of acetylene, nitrogen-containing compounds yielded HCN and/or NO, and sulfur compounds produced H2S, CS2, and COS (14)(15)(16)(17). The pyrolysis on 50% platinized carbon (14) led to the same products (except for benzene and acetylene).…”

Development and service

“…Dry combustion for nitrogen (Dumas) by the procedure of Colson (3), and for carbon and hydrogen by the method of Niederl (J). Oxygen by the Schiitze-Unterzaucher method as modified by Dundy and Stehr (5). Halogen and sulfur by the Parr peroxide bomb procedure for decomposition.…”