Optimization of an Alternative Methodology for Simultaneous Analysis of Nitrite and Nitrate in Water from Urban Stream by Capillary Electrophoresis under Direct UV Detection

Abstract

An alternative methodology for simultaneous determination of nitrite and nitrate by capillary zone electrophoresis using direct detection UV at 210 nm under reverse electrosmotic flow is proposed. The optimization of the electrolyte composition took into account: the buffer and solutes mobilities; the low absorbance of the buffer at 210 nm; the high baseline stability and the short analysis time. The optimized background electrolyte consisted of 100 mmol·L -1 TRIS/HCl buffer and 0.15 mmol·L -1 CTAB at pH 8.2. The proposed method was successfully applied in the analysis of nitrite and nitrate in urban stream samples without usual pretreatment.

Mixture design of an electrolyte system for the simultaneous separation of Cl−, SO42−, NO3−, NO2−, and HCO3− in shrimp-farming water by CZE-UV

“…Aiming at the quantification of Cl − , SO 4 2− , NO 3 − , NO 2 − , and HCO 3 − in shrimp-farming water samples, the single-point standard addition method (SPSA) was implemented, in authentic triplicate. 30,31 For this, the samples were fortified with analyte solutions at a concentration of 750 mg L −1 for Cl − , SO 4 2− and HCO 3 − and 250 mg L −1 for NO 3 − . Thus, the absorbance of the diluted sample and the diluted sample fortified with the analyte solution under analysis were recorded.…”

“…This equation considers that the final volume of the diluted sample and the diluted sample plus the analyte solution are equal. 30,31 where A 1 and A 2 are the absorbance of the diluted samples and diluted samples plus the solution of known concentration, respectively, C s is the concentration of the solution of known concentration in the stock solution, V s is the added volume of the solution of known concentration, and V x is the sample volume. 30,31…”

“…Analytical Methods Paper respectively, C s is the concentration of the solution of known concentration in the stock solution, V s is the added volume of the solution of known concentration, and V x is the sample volume. 30,31 The results are shown in Table 4. The evaluation in this table demonstrated that the method developed and optimized was able to separate and quantify high concentrations of anions in high saline water samples, which is the case in shrimp-farming water.…”

Ratiometric Fluorescent Hydrogel Test Kit for On-Spot Visual Detection of Nitrite

“…To date, many methods for aqueous NO 2 – detection have been developed, such as chemiluminescence, electrochemical methods, , colorimetric methods, , capillary electrophoresis, , spectrophotometry, and chromatography. , Meanwhile, some sensitive and efficient methods are also reported. However, these reported methods either require expensive instruments, tedious detection procedures, and poor visual semiquantitative ability or are time-consuming.…”

“…To date, many methods for aqueous NO 2 − detection have been developed, such as chemiluminescence, 7 electrochemical methods, 8,9 colorimetric methods, 10,11 capillary electrophoresis, 12,13 spectrophotometry, 14 and chromatography. 15,16 Meanwhile, some sensitive and efficient methods are also reported.…”