Related Experiment Video
Updated: Jun 23, 2026
07:00
Accumulation and Analysis of Cuprous Ions in a Copper Sulfate Plating Solution
Published on: March 20, 2019
Molecular characterization of copper in soils using X-ray absorption spectroscopy
Daniel G Strawn1, Leslie L Baker
1Soil and Land Resources Division, P.O. Box 442339, University of Idaho, Moscow, ID 83844-2339, USA. dgstrawn@uidaho.edu
Environmental Pollution (Barking, Essex : 1987)
|May 19, 2009
Summary
Copper speciation in soil is crucial for its bioavailability. This study found copper primarily binds to soil organic matter, specifically humic acid, in a bidentate complex with oxygen or nitrogen functional groups.
Area of Science:
- Environmental Chemistry
- Soil Science
- Geochemistry
Background:
- Copper (Cu) bioavailability in soils is directly influenced by its chemical form (speciation).
- Understanding Cu speciation is essential for assessing its environmental fate and potential toxicity.
Purpose of the Study:
- To investigate copper speciation in six diverse soil samples.
- To determine the primary binding forms and locations of copper within the soil matrix.
Main Methods:
- Utilized X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy.
- Employed synchrotron-based micro X-ray fluorescence (mu-XRF) for elemental mapping.
- Applied principal component analysis and target transform for spectral analysis.
Main Results:
- XANES and EXAFS spectra were consistent across all studied soils.
- mu-XRF showed minimal association of Cu with calcium carbonates, Fe oxides, or Cu sulfates.
- Analysis indicated Cu is predominantly adsorbed onto humic acid (HA), a component of soil organic matter (SOM).
Conclusions:
- Copper in the investigated soils is primarily associated with soil organic matter.
- The molecular structure reveals Cu exists as atoms bound in a bidentate complex to oxygen or nitrogen functional groups within SOM.
Related Concept Videos
01:21Atomic Absorption Spectroscopy: Lab
For AAS measurements, samples must be introduced as clear solutions, often requiring extensive preliminary treatment to dissolve materials like soils, animal tissues, and minerals. Common methods for sample preparation include treatment with hot mineral acids, wet ashing, combustion in closed containers, high-temperature ashing, or fusion with reagents.
Solutions containing organic solvents, such as low-molecular-mass alcohols, esters, or ketones, enhance absorbances by increasing nebulizer...
Solutions containing organic solvents, such as low-molecular-mass alcohols, esters, or ketones, enhance absorbances by increasing nebulizer...
01:27Atomic Absorption Spectroscopy: Overview
Atomic absorption spectroscopy (AAS) is a technique used to analyze elements by measuring electromagnetic radiation (EMR) absorbed by atoms, which causes them to transition to a higher-energy orbit. The most crucial step in AAS is atomization, where the analyte is converted into gas-phase atoms, typically through a flame or furnace. Some of these atoms become thermally excited in the flame, while most remain in the ground state.
When irradiated by EMR of a particular wavelength, these...
When irradiated by EMR of a particular wavelength, these...
01:20Atomic Emission Spectroscopy: Overview
Atomic emission spectroscopy (AES) is an analytical technique used to determine the elemental composition of a sample by analyzing the light emitted from excited atoms. In AES, atoms in a sample are excited to higher energy levels by thermal energy from high-temperature sources, such as plasma, arcs, or sparks. When these excited atoms return to lower energy states, they emit light at specific wavelengths characteristic of each element. The resulting atomic emission spectrum, which consists of...
01:16Spectrophotometry: Introduction
Spectrophotometry is the quantitative measurement of the absorption, reflection, diffraction, or transmission of electromagnetic radiation through a material as a function of the intensity and wavelength of the radiation. A spectrophotometer is a device used to measure the change in the radiation intensity caused by its interaction with the material.
The essential components of a spectrophotometer include a source of electromagnetic radiation, a slot for placing a material to be analyzed, and a...
The essential components of a spectrophotometer include a source of electromagnetic radiation, a slot for placing a material to be analyzed, and a...
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...