Related Experiment Video
Updated: Jun 28, 2026
08:25
Measuring Nitrite and Nitrate, Metabolites in the Nitric Oxide Pathway, in Biological Materials using the Chemiluminescence Method
Published on: December 25, 2016
Selective potentiometric determination of nitrite ion using a novel (4-sulphophenylazo-)1-naphthylamine membrane
Saad S M Hassan1, Sayed A M Marzouk, Hossam E M Sayour
1Department of Chemistry, Faculty of Science, Ain Shams University, Cairo, Egypt.
Talanta
|October 31, 2008
Summary
A new polymeric membrane sensor detects (4-sulphophenylazo-)1-naphthylamine (SPAN) ions. This sensor enables sensitive and selective quantification of nitrite ions in wastewater and food products.
Area of Science:
- Electroanalytical Chemistry
- Polymer Science
- Chemical Sensing
Background:
- Development of selective and sensitive ion-selective electrodes is crucial for environmental and food analysis.
- Polymeric membrane sensors offer advantages in stability and processability.
Purpose of the Study:
- To develop a novel polymeric membrane sensor for the detection of (4-sulphophenylazo-)1-naphthylamine (SPAN).
- To evaluate the sensor's performance for the quantification of nitrite ions.
Main Methods:
- Fabrication of a plasticised PVC membrane sensor incorporating a tris(bathophenanthroline) Ni(II)-SPAN ion pair as the ion exchanger.
- Potentiometric measurements to determine the sensor's response characteristics (slope, linearity, pH range, response time, lifetime).
- Application of the sensor for nitrite determination after conversion to SPAN, with validation against spectrophotometric methods.
Main Results:
- The SPAN sensor exhibited a linear calibration plot with a near-Nernstian anionic slope (-55.0 ± 0.3 mV log[SPAN]⁻¹) over a wide concentration range (10⁻⁶–10⁻² mol L⁻¹).
- The sensor demonstrated a working pH range of 6–8, a rapid response time of 20 s, and an operational lifetime of 8 weeks.
- The sensor was successfully applied for the potentiometric determination of nitrite ions in wastewater and meat products with good sensitivity and selectivity.
Conclusions:
- A novel and effective polymeric membrane sensor for SPAN has been developed.
- The sensor provides a reliable method for the sensitive and selective determination of nitrite ions in complex matrices.
- The developed sensor shows promise for routine analysis in environmental and food safety applications.
Related Concept Videos
01:15Potentiometry: Membrane Electrodes
Membrane electrodes, also known as p-ion electrodes, use membranes that selectively interact with free analyte ions, generating a potential difference across the membrane. The resulting membrane potential, known as the asymmetry potential, is not zero even when analyte concentrations on both sides of the membrane are equal. The membrane's response is typically not selective to a single analyte but proportional to the concentration of all ions in the sample solution capable of interacting at the...
01:19Precipitation Titration: Endpoint Detection Methods
In argentometric precipitation titrations, endpoints can be detected visually by the Mohr, Volhard, and Fajans methods. In the Mohr method, adding a soluble chromate indicator gives an initial yellow color to the analyte solution. As the titrant is added, the first excess of silver ions forms a red silver chromate precipitate, marking the endpoint. The solution pH should be maintained at about 8 by adding solid CaCO3.
In the Volhard method, a standard excess of AgNO3 is first added to the...
In the Volhard method, a standard excess of AgNO3 is first added to the...