Three colorimetric methods for the determination of sulfur dioxide

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1982

OSTI ID:6062688

Chejlava, M J

Three colorimetric methods for the determination of SO/sub 2/ were developed. The first method proposed 4-nitro-1,2-diaminobenzene as a chromogen for use in the West-Gaeke method, replacing pararosaniline which has a large blank absorbance value. 4-nitro-1,2-diaminobenzene is useful in that no blank correction is needed, but with a loss of sensitivity compared to pararosaniline. In the second method 4,4'diaminotriphenylmethyl cation is utilized as the dye. Here again the blank absorbance is negligible and the sensitivity in this method is almost as great as pararosaniline. Cyclohexanone was found to stabilize dissolved bisulfite for periods up to six hours. The third method is a solid reagent which consists of an unglazed porcelain tile coated with a mixture of sodium iodate, ..cap alpha..-naphthoflavone and calcium chloride. Sulfur dioxide reduces the sodium iodate to form iodine which forms a deep blue solid charge transfer complex with the ..cap alpha..-naphthoflavone. The limit of detection for this method is 0.25 ppm SO/sub 2/ in air.

• OSTI ID: 6062688
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102* -- Chemical & Spectral Procedures
500200 -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ABSORPTION SPECTROSCOPY
CHALCOGENIDES
CHEMICAL ANALYSIS
OXIDES
OXYGEN COMPOUNDS
QUALITATIVE CHEMICAL ANALYSIS
SPECTROSCOPY
SULFUR COMPOUNDS
SULFUR DIOXIDE
SULFUR OXIDES