The method of solid-phase extraction (SPE) based on novel carbon materials combined with inductively coupled plasma optical emission spectrometry (ICP-OES) for the determination of erbium in soil and sediment is an analytical approach that integrates efficient enrichment with high-sensitivity detection. Below is a detailed explanation of this method:
1. Method Principle
Solid-Phase Extraction (SPE): Utilizing novel carbon materials as adsorbents, erbium ions in soil and sediment are selectively adsorbed onto the surface of the carbon materials through physical or chemical interactions.
ICP-OES Detection: After enrichment, the samples are eluted and introduced into the ICP-OES instrument. The erbium ions are excited by the high-temperature plasma to emit characteristic spectra, which are then used for quantitative analysis.
2. Selection and Preparation of Novel Carbon Materials
Functionalized Carbon Materials: Carbon materials are chemically modified or grafted with specific functional groups to enhance their adsorption properties. Examples include graphene oxide and porous carbon materials derived from metal-organic frameworks.
Material Characteristics: These materials possess high specific surface areas, abundant adsorption sites, and good chemical stability, enabling efficient capture of erbium ions from complex matrices.
3. Sample Processing and Enrichment
Sample Pretreatment: Soil or sediment samples are subjected to digestion processes, such as microwave digestion or dry ashing, to release erbium ions into solution.
Enrichment Process: The digested sample solution is passed through an SPE column packed with the novel carbon material. The adsorption conditions, including pH, contact time, and flow rate, are optimized to maximize the enrichment efficiency of erbium ions.
4. ICP-OES Detection
Instrument Parameter Optimization: The parameters of the ICP-OES instrument, such as plasma gas flow, auxiliary gas flow, and nebulizer gas flow, are adjusted to achieve optimal signal intensity and stability.
Quantitative Analysis: Quantification of erbium is performed using calibration curves or internal standard methods to ensure accurate and reliable results.
5. Advantages of the Method
High Sensitivity: ICP-OES offers high sensitivity and a wide linear range, allowing for the detection of low concentrations of erbium ions.
High Selectivity: The novel carbon materials exhibit high selectivity for erbium ions, effectively reducing matrix interferences.
Environmentally Friendly: The SPE method reduces the use of organic solvents compared to traditional methods, aligning with the principles of green chemistry.
6. Practical Applications
This method has been successfully applied to the determination of trace amounts of erbium in standard reference materials and real soil and sediment samples, achieving good recovery rates and relative standard deviations. For example, in one study, the saturation adsorption capacity of the novel carbon material for erbium ions reached 47.27 mg/g, with a detection limit of 0.35 ng/mL and a relative standard deviation of 2.1%.
In summary, the solid-phase extraction method based on novel carbon materials combined with ICP-OES is an efficient, sensitive, and environmentally friendly analytical technique suitable for the determination of trace erbium ions in soil and sediment.
