Simple and sensitive determination of trace nitrite in water by zero-crossing first-derivative synchronous fluorescence spectrometry using 6-amino-1,3- naphthalenedisulfonic acid as a new fluorescent probe

Abstract

A new fluorescent probe, 6-amino-1,3-naphthalenedisulfonic acid (ANDSA), has been developed for the determination of trace nitrite in different waters. This probe is based on the selective reaction of nitrite with ANDSA in hydrochloric acid solution to form the corresponding diazonium acid in sodium hydroxide solution at room temperature. The diazonium acid produced has high fluorescence intensity at 488 nm (excitation at 367 nm), whereas ANDSA has high fluorescence intensity at 465 nm (excitation at 354 nm). The synchronous fluorescence (Δλ = 121 nm) spectrum and the first-derivative synchronous fluorescence spectrum of diazonium acid greatly overlapped with those of ANDSA. The zero-crossing method was used to measure the first-derivative value (dF/dλ) of the first-derivative spectra, in which physical separation of excess ANDSA was unnecessary. The zero-crossing point was located at 351.2 nm for ANDSA, at which dF/dλ of diazonium acid was proportional to the nitrite concentration. Therefore, dF/dλ at 351.2 nm was selected as the analytical signal. Under the optimized experimental conditions, the signal intensity was linear over a nitrite concentration range of 0.006-0.075 mg L, with a correlation coefficient better than 0.9994. The limit of detection was 2.1 μg L for the determination of nitrite by the proposed method. The relative standard deviation of the method for the determination of nitrite in real water samples was below 2.45%, and the corresponding recoveries were between 95.7% and 104.1%. The validity of the proposed method was further confirmed by comparison with the reference method with use of the t test. Graphical abstract ANDSA reacts with nitrite to form diazonium acid with higher fluorescence intensity. For ANDSA, dF/dλ was zero at 351.2 nm, whereas dF/dλ of diazonium acid at 351.2 nm was close to the maximum value.

A colorimetric fluorescent probe for rapid and specific detection of nitrite

“…However, with rapid human development, large amounts of industrial wastewater, domestic sewage, and other untreated wastewater are discharged into rivers and lakes arbitrarily, which makes water environmental problems increasingly prominent . NO 2 − is a common pollutant in the water environment . Excessive NO 2 − in the environment poses an increasingly serious threat to human health and ecology .…”

“…[7][8][9] NO 2 − is a common pollutant in the water environment. [10][11][12] Excessive NO 2 − in the environment poses an increasingly serious threat to human health and ecology. [13][14][15][16] Excessive intake of NO 2 in the human body could lead to numerous diseases such as infant methaemoglobinaemia, infant congenital malformation, [17][18][19][20][21][22] central nervous system deficiencies, and cancers.…”

Polyethylenimine-Capped CdS Quantum Dots for Sensitive and Selective Detection of Nitrite in Vegetables and Water

“…For example, 6.5 × 10 –5 M is set to be the maximum limit of nitrite in drinking water, which is recommended by the World Health Organization. To date, various methods have been reported to determine nitrite including chemiluminescence, , spectrofluorimetric, , electrochemical, , chromatographic, and capillary electrophoresis , methods. However, some methods still have limitations on sensitivity, selectivity, simplicity, and feasibility for the detection of trace amounts of nitrite; or instance, some reported works could not distinguish nitrite from the common coexisting nitrate ions. , Spectrofluorimetric methods have attracted interest owing to their high selectivity and sensitivity, as well as simple operability and low-cost advantages .…”

Ultrasensitive and bifunctional ZnO nanoplates for an oxidative electrochemical and chemical sensor of NO2: implications towards environmental monitoring of the nitrite reaction

“…Therefore, the development of new methods for the determination of NO 2 À in food, water and biological uids has received considerable attention by many researchers and these methods can give an indirect determination of NO 2 gas. [24][25][26][27][28] Various analytical methods have already been developed to determine NO 2 À including colorimetry, 29 chromatography, 30 uorometry, 31 spectrophotometry 32 and electrochemical methods [33][34][35][36][37] for the quantitative and qualitative determination of NO 2…”