2.6 Inductively Coupled Plasma-Atomic Emission Spectroscopy Lab Report
2.2.1.6 Inductively Coupled Plasma-Atomic Emission Spectroscopy
Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) is one of several techniques available in analytical atomic spectroscopy. ICP-AES utilizes plasma as the atomization and excitation source. Plasma is an electrically neutral, highly ionized gas that consists of ions, electrons, and atoms. Most analytical plasmas operate with pure argon or helium, which makes combustion impossible. Plasmas are characterized by their temperature, as well as their electron and ion densities. Analytical plasmas typically range in temperature from 6000 to 8,000K. The procedure involves;
1. Sample Preparation: Some samples require special preparation steps including treatment with acids, …show more content…
To do so, the ions are extracted through a number of apertures. Besides ions, photons are produced in the plasma. Photons (minute energy packet of electromagnetic radiation) also pass through the apertures. They are not removed by vacuum and produce high background signal when they reach the detector. To minimize this background, a so-called photon-stop is present. This is a small metal plate placed in the centre of the ion beam, which reflects the photons away from the detector. The positive ions are not stopped by the photon-stop because a positively charged cylinder lens guides them around it.
Subsequently, the positive ions in the plasma are focused down the quadropole mass analyser. In the quadrupole the ions are separated on the basis of their mass-to-charge ratio. Each element has its own characteristic isotopes and masses and will therefore produce its own mass spectrum. After passing the quadrupole the ions hit a special detector. It contains two stages to allow simultaneous measurements of high and low signals. This allows simultaneous detection of main components and ultra-trace elements in a single run, which makes the ICP-MS a perfect tool for survey analysis of totally unknown …show more content…
Microwave digestion is the perfect compliment to ICP-MS, ensuring rapid, clean digestions with no analyte loss. Microwave-assisted digestion in closed vessels is the best in the preparation of sample. This allows a contamination-free environment, as well as a single preparation method for all elements of interest. The high pressure rotor and vessels are recommended. A half gram of material should be weighed into a multiwave vessel. Concentrated HNO3 should add, and the solution swirled to ensure wetting and mixing. Finally, H2O2 solution must be added slowly and allowed to react. The vessels should then be sealed. Upon completion of the digestion, deionised water should be added to the samples. Samples may then be diluted 1:10 with deionized water prior to analysis, and internal standards added. Quantitation can then be done against aqueous, external calibration
Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) is one of several techniques available in analytical atomic spectroscopy. ICP-AES utilizes plasma as the atomization and excitation source. Plasma is an electrically neutral, highly ionized gas that consists of ions, electrons, and atoms. Most analytical plasmas operate with pure argon or helium, which makes combustion impossible. Plasmas are characterized by their temperature, as well as their electron and ion densities. Analytical plasmas typically range in temperature from 6000 to 8,000K. The procedure involves;
1. Sample Preparation: Some samples require special preparation steps including treatment with acids, …show more content…
To do so, the ions are extracted through a number of apertures. Besides ions, photons are produced in the plasma. Photons (minute energy packet of electromagnetic radiation) also pass through the apertures. They are not removed by vacuum and produce high background signal when they reach the detector. To minimize this background, a so-called photon-stop is present. This is a small metal plate placed in the centre of the ion beam, which reflects the photons away from the detector. The positive ions are not stopped by the photon-stop because a positively charged cylinder lens guides them around it.
Subsequently, the positive ions in the plasma are focused down the quadropole mass analyser. In the quadrupole the ions are separated on the basis of their mass-to-charge ratio. Each element has its own characteristic isotopes and masses and will therefore produce its own mass spectrum. After passing the quadrupole the ions hit a special detector. It contains two stages to allow simultaneous measurements of high and low signals. This allows simultaneous detection of main components and ultra-trace elements in a single run, which makes the ICP-MS a perfect tool for survey analysis of totally unknown …show more content…
Microwave digestion is the perfect compliment to ICP-MS, ensuring rapid, clean digestions with no analyte loss. Microwave-assisted digestion in closed vessels is the best in the preparation of sample. This allows a contamination-free environment, as well as a single preparation method for all elements of interest. The high pressure rotor and vessels are recommended. A half gram of material should be weighed into a multiwave vessel. Concentrated HNO3 should add, and the solution swirled to ensure wetting and mixing. Finally, H2O2 solution must be added slowly and allowed to react. The vessels should then be sealed. Upon completion of the digestion, deionised water should be added to the samples. Samples may then be diluted 1:10 with deionized water prior to analysis, and internal standards added. Quantitation can then be done against aqueous, external calibration