Determination of nitrite and nitrate in a proposed certified reference material for nutrients in seawater by capillary zone electrophoresis with artificial seawater as the background electrolyte using transient isotachophoresis

Abstract

We describe a combination of selected ions as a terminating ion which is useful for transient isotachophoresis (ITP) in capillary zone electrophoresis (CZE) for the determination of nitrite and nitrate in seawater. In addition to 150 mM sulfate as the principal terminating ion, 10 mM bromate was added to a sample solution as the additional terminating ion. Artificial seawater containing 3 mM cetyltrimethylammonium chloride (CTAC) was adopted as a background electrolyte (BGE). The limits of detection (LODs) for nitrite and nitrate were 2.2 and 1.0 microg/L (as nitrogen), respectively. The LODs were obtained at a signal to noise ratio (S/N) of 3. The values of the relative standard deviation (RSD) of peak area for these ions were 1.9 and 1.4%. The RSDs of peak height were 1.7 and 1.9%, the RSDs of migration time 0.11%. The proposed method was applied to the determination of nitrite and nitrate in a proposed certified reference material for nutrients in seawater, MOOS-1, distributed by the National Research Council of Canada (NRC). The results almost agreed with the assigned tolerance interval.

A simple and sensitive spectrophotometric method for the determination of trace amounts of nitrite in environmental and biological samples using 4-amino-5-hydroxynaphthalene-2,7-disulphonic acid monosodium salt

“…There are numerous methods developed so far for the determination of nitrite in environmental samples, which include spectrofluorometry [10][11][12], chromatography [13][14][15][16], potentiometry [17][18][19], capillary electrophoresis [20][21][22], membrance sensors [23,24], flow injection analysis [25][26][27][28][29], electroanalytical [30,31], and amperometric [32,33]. Most of these methods are not suitable for routine determination of nitrite in environmental samples because some of them are costly or need skilled person to handle.…”

Simultaneous determination of nitrate and nitrite in biological fluids by capillary electrophoresis and preliminary study on their determination by microchip capillary electrophoresis

“…Previously, we have investigated anion analysis in seawater by capillary zone electrophoresis (CZE), using a running buffer similar to artificial seawater composition [19] in order to reduce the very high chloride peak and also to concentrate the sample zone by stacking and/or transient isotachophoresis (tITP) [20][21][22][23][24]. Therefore, based on this methodology, we have developed a novel running buffer based on human serum components after deproteinization, because human serum is, like seawater, a sample matrix of high ionic strength.…”

A Simple Flow Injection Spectrophotometric Determination of Nitrite Based on Its Reaction with Thiourea

“…Various methods have been used for the determination of nitrite, including chromatography, 4-7 gas chromatography-mass spectrometry, 8 capillary electrophoresis, [9][10][11] colorimetric methods, [12][13][14][15][16][17][18][19][20][21][22][23] catalytic-based methods, [24][25][26] and several other methods such as electrochemical ones, 27-29 fluorometric ones 30,31 and chemiluminescence. [32][33][34] Flow injection analysis (FIA) in combination with one of the above detection methods have been widely used for the determination of nitrite.…”