Simultaneous Detection Of Nitrite Research Articles

Fast and simultaneous detection of dissolved BOD and nitrite in wastewater by using bioelectrode with bidirectional extracellular electron transport

Timely and simultaneously detecting BOD and nitrite concentrations is of great significance for curbing of water pollution and adjusting wastewater treatment strategies. However, existing BOD and nitrite biosensors cannot perform synchronous detection due to their single electroactivity and differences in detection time. This study reported a novel dual-function electrochemical biosensor (DFEB) that could perform fast, simultaneous detection of nitrite and dissolved BOD. DFEB conducted a potential-step chronoamperometry on the mixed-bacteria bioelectrode with bidirectional electron transfer ability to obtain response signals. DFEB accurately measured dissolved BOD in the range of 5 ∼ 100 mg BOD L−1 and nitrite in the range of 0.05 ∼ 16 mg NO2−-N L−1 within 20 min and maintain stable performance over 200 tests. DFEB performed well in artificial wastewater, aquatic wastewater, anaerobic tank effluent and anammox effluent, with relative errors < 15.7% and 16.8% in detecting nitrite and dissolved BOD, respectively. Our study provided a feasible way to develop multifunctional biosensors for detecting pollutants with different redox properties in wastewater.

Simultaneous Detection of Nitrite and Nitrate in Celeries and Carrots

In this study, the anions nitrite ion (NO2-) and nitrate ion (NO3-) in celeries and carrots were detected with the technique of ion chromatography. A Dionex ICS-2000 ion chromatograph was used to detect the content of NO2- and NO3- in celeries and carrots. NO2- and NO3- were separated on a DIONEX Ionpac AS19 A-4 mm ion-exchange column and an Iopac AG AS19 A-4 mm guard column. The eluant was suppressed with an anion electrical self-regenerating suppressor (ASRS 300) and the content of NO2- and NO3- was detected with a conductivity detector. The detection limits were obtained for anions NO2- and NO3-. The present results showed that the ion chromatography was a suitable technique for the simultaneous determination of NO2- and NO3- in vegetables.

Determination of nitrate and nitrite in rat brain perfusates by capillary electrophoresis.

A fast and simple method for the direct, simultaneous detection of nitrite (NO(2) (-)) and nitrate (NO(3) (-)) in rat striatum has been developed using a capillary electrophoresis separation of low-flow push-pull perfusion samples. The method was optimized primarily for nitrite because nitrite is more important physiologically and is found at lower levels than nitrate. We obtained a complete separation of NO(2) (-) and NO(3) (-) in rat striatum within 1.5 min. Optimal CE separations were achieved with 20 mM phosphate, 2 mM cetyltrimethylammonium chloride (CTAC) buffer at pH 3.5. The samples were injected electrokinetically for 2 s into a 40 cm x 75 microm ID fused-silica capillary. The separation voltage was 10 kV (negative polarity), and the injection voltage was 16 kV (negative polarity). UV detection was performed at 214 nm. The limits of detection obtained at a signal-to-noise ratio (S/N) of 3 for nitrite and nitrate were 0.96 and 2.86 microM. This is one of the fastest separations of nitrite and nitrate of a biological sample ever reported. Interference produced by the high physiological level of chloride is successfully minimized by use of CTAC in the run buffer.

High Performance Ion Chromatography Determination of Nitrite and Nitrate in Foodstuffs

Abstract An alternative chromatographic method has been developed to selective and simultaneous detection of nitrite and nitrate in the presence of chloride, based on the use of an anion-exchange polymethacrylate column with 5mM phosphate buffer as eluent and ultraviolet absorbance at 214 nra as detection procedure. The detection limit was 0.5 μg/ml for both anions. This method was shown to be applicable to the analysis of several foodstuffs.