Reduction: distillation method for sulfate determination

Journal Article · Wed Oct 01 04:00:00 EDT 1980 · Anal. Chem.; (United States)

DOI:https://doi.org/10.1021/ac50062a048· OSTI ID:6767320

Siemer, D D

This article describes an improvement of the reduction/distillation/spectrophotometric technique that is widely used in the nuclear industry. The procedure involves the reduction of oxidized forms of sulfur to hydrogen sulfide with a hot solution containing hydroiodic acid, sodium hypophosphite, and acetic acid. The hydrogen sulfide is sparged from the reaction mixture with nitrogen which is then bubbled through a dilute zinc acetate solution which traps the sulfide. The addition of acid, p-aminodimethylaniline, and ferric chloride to the zinc acetate trapping solution quantitatively converts the sulfide to methylene blue which is then measured by absorption spectrophotometry at 667 nm. In this version of the technique, the samples and standard are added serially to a single, relatively large batch of the boiling reduction solution. The apparatus is not cooled down and disassembled between each sample run and the reduction solution is kept at a boil at all times and is continuously sparged with nitrogen gas. This reduces the total analysis time to a fraction of that necessary with the previous methods. Tables are presented summarizing the studies on: effect of matrix constituents on the determination of 100 ..mu..g of sulfate; effects of nitrates; and comparison of ion chromatographic results with those obtained by the sulfate reduction techniques. Agreement between values is good for these two techniques. The overall time for the analysis of a single solution sample is on the order of 10 min including the delay for color development. The relative standard deviations obtained on finely ground solid calcined nuclear waste containing from 0.1 to 10% sulfur as sulfate are typically on the order of 3 to 5%.

• Research Organization: Exxon Nuclear Idaho Co., Idaho Falls
• OSTI ID: 6767320
• Journal Information: Anal. Chem.; (United States), Journal Name: Anal. Chem.; (United States) Vol. 52:12; ISSN ANCHA
• Country of Publication: United States
• Language: English

Related Subjects

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12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400104* -- Spectral Procedures-- (-1987)
ABSORPTION SPECTROSCOPY
ANIONS
CALCINED WASTES
CHARGED PARTICLES
CHEMICAL ANALYSIS
CHEMICAL REACTIONS
CHROMATOGRAPHY
COMPARATIVE EVALUATIONS
DISTILLATION
ELEMENTS
ION EXCHANGE CHROMATOGRAPHY
IONS
MATERIALS
NITRATES
NITROGEN COMPOUNDS
NONMETALS
OXYGEN COMPOUNDS
QUANTITATIVE CHEMICAL ANALYSIS
RADIOACTIVE MATERIALS
RADIOACTIVE WASTES
REDUCTION
SEPARATION PROCESSES
SPECTROSCOPY
SULFATES
SULFUR
SULFUR COMPOUNDS
WASTES