Related Experiment Video
Updated: Jul 12, 2026
11:50
Metal-silicate Partitioning at High Pressure and Temperature: Experimental Methods and a Protocol to Suppress Highly Siderophile Element Inclusions
Published on: June 13, 2015
Extraction and determination of elemental selenium in sediments--a comparative study.
Yu-Wei Chen1, Lu Li, Alessandro D'Ulivo
1Department of Chemistry and Biochemistry, Laurentian University, Ramsey Lake Road, Sudbury P3E 2C6, Canada. ychen@laurentian.ca
Analytica Chimica Acta
|August 29, 2007
Summary
A new method using carbon disulfide (CS2) effectively extracts elemental selenium (Se) from soil and sediment. This technique offers superior selectivity and accuracy compared to traditional sodium sulfite (Na2SO3) methods for selenium analysis.
Area of Science:
- Environmental Chemistry
- Analytical Chemistry
- Geochemistry
Background:
- Elemental selenium (Se) extraction from environmental matrices like soil and sediment is crucial for accurate geochemical and environmental studies.
- Traditional methods, such as sodium sulfite (Na2SO3) extraction, have shown limitations including lack of selectivity and potential for over-extraction.
- The purity and solubility characteristics of commercially available elemental selenium standards can impact analytical results.
Purpose of the Study:
- To develop and validate a new, selective technique for extracting elemental selenium from soil and sediment samples.
- To compare the efficiency, selectivity, and accuracy of carbon disulfide (CS2) extraction against the conventional Na2SO3 method.
- To investigate the composition and solubility of a commonly used red elemental selenium standard.
Main Methods:
- Characterization of a red elemental selenium standard (PF-Se) to determine its composition, including amorphous and monoclinic forms.
- Solubility tests of elemental selenium in carbon disulfide (CS2).
- Extraction of elemental Se from soil and sediment samples using CS2 and Na2SO3.
- Analysis of extracted selenium using Hydride Generation-Atomic Fluorescence Spectrometry (HG-AFS).
Main Results:
- The red elemental selenium standard (PF-Se) was found to be impure, containing amorphous elemental Se, oxidized Se, and monoclinic elemental Se.
- Carbon disulfide (CS2) demonstrated selective solubility for elemental selenium, unlike Na2SO3 which dissolved all forms of selenium in PF-Se.
- CS2 extraction proved simpler, more precise, selective, and accurate than Na2SO3 extraction.
- The CS2 extraction method, coupled with HG-AFS, achieved a low detection limit of 1.0 ng g(-1) in sediment samples due to minimal reagent blank.
Conclusions:
- Carbon disulfide (CS2) is a highly effective and selective solvent for extracting elemental selenium from soil and sediment.
- The proposed CS2 extraction technique offers significant advantages in terms of simplicity, precision, accuracy, and selectivity over the Na2SO3 method.
- This improved extraction method enables highly sensitive selenium determination in environmental samples.
Related Concept Videos
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...
01:08Sample Preparation for Analysis: Advanced Techniques
Accurate analysis of complex samples often requires advanced preparation techniques to achieve reliable and reproducible results. Samples containing inorganic or organic materials can be challenging to dissolve or decompose effectively. Standard sample preparation methods include acid digestion, fusion, dry ashing, and wet digestion.
Acid digestion with strong acids is commonly used to dissolve inorganic materials that are insoluble (do not dissolve) in water. This method can be useful for...
Acid digestion with strong acids is commonly used to dissolve inorganic materials that are insoluble (do not dissolve) in water. This method can be useful for...
00:56Extraction: Advanced Methods
Metal ions can be separated from one another by complexation with organic ligands–the chelating agent– to form uncharged chelates. Here, the chelating agent must contain hydrophobic groups and behave as a weak acid, losing a proton to bind with the metal. Since most organic ligands used in this process are insoluble or undergo oxidation in the aqueous phase, the chelating agent is initially added to the organic phase and extracted into the aqueous phase. The metal-ligand complex is formed in...