International Journal of Chemical Studies
Vol. 4, Issue 3 (2016)
Spectrophotometric determination of nitrite and nitrate ions by diazo coupling method
Author(s): Nagaraj P, Gopalakrishna Bhat N and Chandrashekara KG
Abstract: A new spectrophotometric method is investigated for the rapid, sensitive and selective determination of nitrite and nitrate in water and soil samples. It is based on the tetrazotization of benzidine with nitrite, in acid medium to form bisdiazonium ion, which is then coupled with resorcinol. The orange coloured azo dye formed in basic medium, shows absorption maximum at 463.5 nm. The method is optimized for temperature, acidity, amount of reagents required and tolerance amount of anions and cations. The Beer-Lambert’s plot shows linearity up to 2.8 µg cm-3 of nitrite. The molar absorptivity and Sandell’s sensitivity are found to be 2.1524 x 104 dm3 mol-1 cm-1 and 0.0033 µg cm-2 respectively. The investigated method has detection limit as 0.0049 μg cm-3 and quantitation limit as 0.0102 μg cm-3. The method is applied for the determination of trace amount of nitrite and nitrate in water and soil samples. The results are statistically evaluated.
Pages: 101-105 | 1029 Views 26 Downloads
How to cite this article:
Nagaraj P, Gopalakrishna Bhat N, Chandrashekara KG. Spectrophotometric determination of nitrite and nitrate ions by diazo coupling method. Int J Chem Stud 2016;4(3):101-105.