ТВЕРДОФАЗНО-СПЕКТРОФОТОМЕТРИЧЕСКОЕ ОПРЕДЕЛЕНИЕ НИТРИТОВ В ВОДЕ С ИСПОЛЬЗОВАНИЕМ РЕАКТИВА ГРИССА И САФРАНИНА, ИММОБИЛИЗОВАННЫХ В ПОЛИМЕТАКРИЛАТНОЙ МАТРИЦЕ

Abstract

This paper presents a solid phase spectrophotometric method for the nitrite determination with safranin and Griess reagent immobilized in a transparent polymethacrylate matrix. The proposed method is based on the interaction between the nitrites in water with reagents immobilized into the matrix and the formation of azocompound in the solid phase. The use of the Griess reagent leads to the formation of the azocolored compound with an absorption maximum at 490 nm. In the case of using safranin the decrease in absorbance at 530 nm is observed. The optimal conditions for the nitrite determination and interference from foreign ions were studied and the analytical performance characteristics of the developed method were estimated. The optimized conditions gave the response time of 15 min and pH = 1 for when using the Griess reagent. Nitrite interacts with safranin in polymethacrylate matrix in strongly acidic media (pH ~ 0) for 5 min. Under these experimental conditions the ranges of determined concentrations are 1.0-3.0 mg/L with 3 s detection limit of 0.9 mg/L and 1.0-5.0 mg/L with the limit of detection of 0.5 mg/L when using immobilized in matrix Griess reagent and safranin respectively. The proposed methods were successfully applied to the determination of nitrites in drinking and mineral water. These methods are simple, inexpensive, non-toxic, and fast and use only the conventional instrumentation. Keywords: nitrite, polymethacrylate matrix, immobilized reagents, solid-phase spectrophotometry. (Russian) DOI: http://dx.doi.org/10.15826/analitika.2015.19.3.004 N.A. Gavrilenko 1 , N.V. Saranchina 2 , A.V. Sukhanov 1 1 Federal State Autonomous Educational Institution of Higher Education «National Research Tomsk Polytechnic University», Tomsk, Russian Federation 2 Federal State Autonomous Educational Institution of Higher Education «National Research Tomsk State University », Tomsk, Russian Federation