Related Experiment Video
Updated: Jun 28, 2026
07:00
Accumulation and Analysis of Cuprous Ions in a Copper Sulfate Plating Solution
Published on: March 20, 2019
Absorptiometric determination of sulphide ion
1Department of Chemistry, Imperial College of Science and Technology,London, S.W.7 U.K.
Talanta
|September 1, 1970
Summary
A new absorptiometric method detects sulphide ions using a green color reaction with iron(III) and nitrilotriacetic acid. This sensitive technique accurately quantifies sulphide in various samples, with minimal interference from other anions.
Area of Science:
- Analytical Chemistry
- Environmental Chemistry
Background:
- Sulphide ion (S²⁻) is a critical analyte in environmental and industrial samples.
- Accurate quantification of sulphide is essential for monitoring water quality and industrial processes.
Purpose of the Study:
- To develop a novel absorptiometric method for sensitive and selective sulphide ion determination.
- To establish a reliable analytical procedure for sulphide quantification in diverse matrices.
Main Methods:
- The method involves the reaction of sulphide ions in an ammoniacal solution with iron(III) and excess nitrilotriacetic acid.
- A distinct green color forms, which is measured spectrophotometrically.
- The color system is stabilized using an excess of sulphite to enhance accuracy.
Main Results:
- The developed procedure accurately quantifies sulphide ions in the range of 1200 down to 8 ppm.
- The method exhibits high selectivity, with serious interference observed only from selenite among seventeen other tested anions.
- The study provides insights into the nature of the colored complex and its formation mechanism.
Conclusions:
- The described absorptiometric method offers a sensitive, selective, and reliable approach for sulphide ion analysis.
- The technique is suitable for routine analysis due to its robustness and minimal interference.
- Further investigation into the color body and reaction mechanism can optimize analytical performance.
Related Concept Videos
03:45Formation of Complex Ions
A type of Lewis acid-base chemistry involves the formation of a complex ion (or a coordination complex) comprising a central atom, typically a transition metal cation, surrounded by ions or molecules called ligands. These ligands can be neutral molecules like H2O or NH3, or ions such as CN− or OH−. Often, the ligands act as Lewis bases, donating a pair of electrons to the central atom. These types of Lewis acid-base reactions are examples of a broad subdiscipline called coordination...
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...
01:17Precipitation and Co-precipitation
Precipitation and coprecipitation methods can be used to separate a mixture of ions in a solution. In qualitative inorganic analysis, ions that form sparingly soluble precipitates with the same reagent are separated based on the differences in solubility products. For example, consider the separation of Cu(II) and Fe(II) ions by precipitation as insoluble sulfides. First, copper(II) sulfide is precipitated by the addition of acidic H2S, where the dissociation of H2S is suppressed. Adding H2S...
01:23Redox Titration: Iodimetry and Iodometry
Iodometry and iodimetry are analytical methods used to determine the concentration of oxidizing or reducing agents using iodine. In iodometric titrations, the oxidizing analyte solution is usually acidified and treated with an excess of iodide ions, which generates an equivalent amount of iodine in equilibrium with triiodide. The released iodine is subsequently titrated directly against a standardized reducing agent. As the dilute iodine color becomes pale yellow, a few drops of freshly...