Oxygen Flask Combustion Ion Chromatography

Combustion of polymers in an oxygen-filled flask over aqueous solutions of appropriate reagents converts elements such as halogens, phosphorus and sulfur into inorganic anions. 

Subsequent analysis of these solutions by ion chromatography [14] enables the concentrations of mixtures of these anions (i.e., the original elements) to be determined rapidly, accurately, and with great sensitivity. 

Instrumentation for ion chromatography is discussed in Section 1.1.15. See also Appendix 1. 

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The first step in determination of total sulfur in pulp by combustion/ion chromatography entails burning the pulp in a Schoniger combustion flask (Douek and Ing 1989). Combustion of the pulp in an oxygen atmosphere in a platinum boat oxidizes the sulfur to sulfate which dissolves in deionized water at the bottom of the flask. The presence of a few drops of hydrogen peroxide in the deionized water ensures that oxidation to sulfate is complete. 

Chlorine Oxygen flask combustion followed by ion chromatography Oxygen flask combustion followed by ion chromatography Colorimetric ... 

See also Air Analysis Sampling. Ion Exchange Ion Chromatography Instrumentation. Sample Dissolution for Elemental Analysis Dry Ashing Oxygen Flask Combustion Wet Digestion Microwave Digestion. Water Analysis Overview Freshwater. 

Ion chromatography has been successfully applied to the quantitative analysis of ions in many diverse types of industrial and environmental samples. The technique has also been valuable for microelemental analysis, e.g. for the determination of sulphur, chlorine, bromine, phosphorus and iodine as heteroatoms in solid samples. Combustion in a Schoniger oxygen flask (Section 3.31 )is a widely used method of degrading such samples, the products of combustion being absorbed in solution as anionic or cationic forms, and the solution then directly injected into the ion chromatograph. 

Combustion of the sample in an oxygen combustion flask (Alcino et al., 1965) followed by ion chromatography is an attractive method for the analysis of sulfur in humic substances. Not only does the method require relatively little sample and provide high sensitivity, but it also allows simultaneous determination of halogens. One must be sure that sulfur is not rendered insoluble by ash constituents such as calcium. 

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