Inductively Coupled Plasma with Optical Emission Spectroscopy (ICP-OES)
Description of method
ICP-OES makes use of the fact that the atoms of elements can take up energy from an inductively coupled plasma, are thereby excited, and fall back into their ground state again emitting a characteristic radiation. The identification of this radiation permits the qualitative analysis of a sample. A quantitative determination takes place on the basis of the proportionality of radiation intensity and element concentration in calibration and analysis samples.
In ICP-OES analysis, the liquid sample is introduced into the inductively generated argon plasma through a nebulizer system and excited. The spectrum emitted is transferred into a spectrometer where it is decomposed into the individual wavelengths and evaluated. The intensities of the spectral lines are measured by CID semiconductor detectors. Calibration is effected with multi-element solutions mixed from standard solutions.
Features of ICP-OES
- The method is suited for multi-element determination in solutions or after appropriate sample preparation of solid samples brought into solution.
- Detectable elements: approx. 70, determinable concentration range from a few µg/l up to 2 % in solution or 1 µg/g up to 100 % in solids.
- Precision: 1 - 3 % for major elements, ± 10-30 % for traces.
- Particularly suited for stoichiometry determinations, material controls, material determinations
- Test quantities at least 1-0 mg for major elements, 100-500 mg for traces.
- Measurement times of generally a few minutes per sample;
for solid samples, a possibly time-consuming sample preparation must be taken into account.
Digestion methods such as microwave, high-pressure, fusion, and acid digestion are employed for the sample preparation of solid sample material.
Steels, nickel-base alloys, light metals, rock, coals, ashes, glasses, ceramics, water and waste water samples, soils, plants, nutrient solutions, oils, bulk analysis of thin films, high-temperature superconductors, mixed oxides, perovskites, electroceramic materials, zirconium oxides and others.
TJA-IRIS-INTREPID: spectrometer with echelle optics and CID semiconductor detector, axial and radial viewing, wavelength range 165 - 900 nm
Thermo Scientific iCAP6500: spectrometer with echelle-optics and CID semiconductor detector, axial and radial viewing, wavelength range 166-847 nm
Thermo Scientific iCAP7600: spectrometer with echelle-optics and CID semiconductor detector, axial and radial viewing, wavelength range 166-847 nm