Analytical Chemistry Optical Chemosensor for Spectrophotometric Determination of Nitrite in Wastewater

Abstract

An easy, sensitive, and rapid spectrophotometric method has been documented for determining nitrite (NO 2 À ) in water and wastewater. To detect and adsorb harmful nitrite ions from wastewater efficiently; a stable optical nanosensor was manufactured by immobilization of 1-Naphthylamine (1-NA) over mesoporous silica nanospheres (MSNs). The determination of nitrite was based on the reaction of nitrite with the optical sensor (1-NA chemosensor) and forming diazonium salt which was subsequently coupled with N-(1-Naphthyl) ethylenediamine dihydrochloride (NED) to form a stable brownish azo dye. The dye shows an absorption maximum at 457 nm. The optimal conditions for the reaction and the analytical parameters were evaluated. The method has been designed by controlling the acidity, the quantity of reagents required and the amount of tolerance of certain ions. The range of linearity was found to be 0.108-10.8 μM of nitrite. The nitrite identification detection limit and quantitation limit are 0.106 μM and 0.353 μM, respectively. The performance of the chemosensor in extracting the NO 2 À ions was tested. According to the Langmuir isotherms, the adsorption pattern was highly competent, where the removal capacity for NO 2 À ion was 156.0 mg/g by the chemosensor. Some cations and anions have been identified as the competing ions; these ions were not affected on the NO 2 À ion in both detection and adsorption processes.[a] Prof.

Film Carbon Veil-Based Electrode Modified with Triton X-100 for Nitrite Determination

“…Thus, exploiting effective means for nitrite detection in food products, biological fluids and water is essential for human health and environmental protection. Hence, different physical-chemical methods for nitrite detection have been proposed, such as chromatography [1,6], titration [7,8] spectrophotometry [9,10] and electrochemistry [11,12]. Along with obvious advantages they have some shortcomings.…”