Spectrophotometric determination of nitrogen dioxide in air and nitrite in water and soil samples

Journal Article · Wed Feb 01 04:00:00 EST 1995 · Analytical Letters

DOI:https://doi.org/10.1080/00032719508001114· OSTI ID:75783

Pandurangappa, M; Balasubramanian, N ^[1]

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1. Indian Institute of Technology, Madras (India)

A sensitive spectrophotometric method for the determination of nitrogen dioxide in air and nitrite in water and soil samples is described. Nitrogen dioxide in air is fixed as nitrite ion in alkaline sodium arsenite or in triethanolamine absorber solutions. The method is based on the diazo coupling reaction between p-nitro aniline and 1-hydroxy-2-naphthoic acid. The azo dye formed under aqueous condition has an absorption maximum at 585nm and obeys Beer`s law over the range 0-25{mu}g of nitrite. The colour system is stable for 72h. The relative standard deviation is 2.7% for ten determinations at 15{mu}g of nitrite. The dye is extracted with 1:1 isoamyl alcohol-IBMK mixture and stabilisation with methanolic potassium hydroxide showed {lambda}{sub max} at 610nm. It obeys Beer`s law over the range 0-4{mu}g of nitrite. The colour system is stable for 40h in organic phase and the relative standard deviation is 2.5% for ten determinations at 3{mu}g of nitrite. The molar absorptivity of the colour system is 3.68 x 10{sup 4} Lmol{sup {minus}1} cm{sup {minus}1}. The effect of interfering gases and other ions on the determination of nitrite is described. The developed method has been applied for the determination of residual nitrogen dioxide gas present in the laboratory fume cupboard and automobile exhaust gases. In addition, the method has been applied for the determination of nitrite and nitrate in samples like water, soil and radiator coolants.

• Sponsoring Organization: USDOE
• OSTI ID: 75783
• Journal Information: Analytical Letters, Journal Name: Analytical Letters Journal Issue: 3 Vol. 28; ISSN ANALBP; ISSN 0003-2719
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
54 ENVIRONMENTAL SCIENCES
AIR
CHEMICAL ANALYSIS
EXHAUST GASES
NITRITES
NITROGEN DIOXIDE
SOILS
SPECTROPHOTOMETRY
WATER