Selective electrocatalytic method for the determination of nitrite

Abstract

The reduction of Mo(VI) at -0.48 V vs. SCE In a pH 2.1 solution of 0.1 mM Na2Mo04, 0.1 M KCI results In a deposit on mercury and graphite electrodes which selectively catalyzes nitrite reduction. With linear potential scan voltammetry, a peak Is developed at -0.88 V In direct proportion to nitrite concentration over the range 0.01-1 mM. Nitrate does not interfere until It reaches about a 100-fold excess at which point It causes an Increase in the analytical current. Neither chloride nor sulfate Interfere. Dissolved oxygen causes a correctable Increase In the base-line current. The electroactive species was shown to be HN02. Under the recommended conditions, chemical decomposition was Insignificant for at least 30 min, but sparging the pH 2.1 solution with N2 to remove dissolved oxygen must not exceed 10 min to prevent significant volatility loss.

Kinetic determinations and some kinetic aspects of analytical chemistry

“…Although the bulk of catalytic determinations involves homogeneous systems, a few based on heterogeneous, electrochemical systems have been reported. Molybdenum (VI), for instance, reduced at -0.48 vs. the SCE (pH 2.1, 0.1 mM Na2Mo04, and 0.1 M KC1) produces a deposit on mercury and graphite which selectively catalyzes the reduction of nitrite ions (49). Nitrate does not interfere up to a 100-fold excess.…”

A (μ-oxo) dicopper complex anchoring graphitized mesoporous carbon surface prepared by an in situ electrochemical method for bioinspired electrocatalytic reduction of nitrite to ammonia and sensing

“…[5][6][7] The ecological and environmental importance of the microbial transformations of nitrite within the N-cycle has thus gained much attention and driven extensive research over the last ve decades (Besson et al provide a detailed account of this topic). 8 Major progress was made in the characterization of the bacterial enzymes performing these reactions and their catalytic mechanisms, 3,8 as well as on potential applications in radioactive waste conversion, 9 clinical diagnoses, 10 biosensors, [11][12][13][14][15] electrocatalysis, [16][17][18][19][20][21][22] and electrochemical sensing. [23][24][25][26][27][28][29][30][31][32] In this work, we will focus on the direct nitrite reduction into ammonium, NO 2 − + 8H + + 6e − / NH 4 + + 2H 2 O (E o0 = 0.103 vs.…”