Inductively coupled plasma optical emission spectrometry is a process in analytical chemistry where the elemental composition of mostly water-dissolved samples is detected through the use of a spectrometer and plasma. This technique has been used since its commercial availability in 1974.
The ICP OES, as it is also called, is known for its high throughput, precise measurements, and reliability, not to mention, its multi-element benefits. Owing to all of its contributing attributes, the technique is widely used in research and routine chemical analysis.
As intriguing as a technique it is, we are going to further shed some light on the ICP OES principle through the FAQs below.
What is the Principle of ICP OES?
As per the principle, the atoms and ions are capable of absorbing energy, stimulating the electrons to move from their ground state to a state of excitement. In Inductively coupled plasma optical emission spectrometry, the energy source is the heat introduced through the argon plasma operating at high temperatures of 10,000 kelvins.
The principle of inductively coupled plasma optical emission spectrometry depends on the excited atoms to generate light at precise wavelengths while transitioning into lower levels of energy.
As per the principle, the quantity of light generated at each precise wavelength is proportionate to the number of ions or atoms created during the transition phase.
How does the ICP OES apparatus work?
The inductively coupled plasma optical emission spectrometry apparatus includes the following elements:
- An introduction system for the sample.
- Plasma torch.
- Radio-frequency producer.
- Optical spectrometer.
- Digital apparatus control for data collection & analysis.
Given below are the steps mentioning the function of the apparatus:
- The argon plasma is used to excite the atoms or ions.
- The intensity of the light produced and released from ions or atoms when the electrons transition into the ground state is measured.
- As per the calibration graph, the concentration of particular elements in the sample is calculated.
What is ICP-OES Analysis?
The ICP OES principle relies on the analysis process described in the steps below:
- Selection of the composition elements of the sample for measurement.
- Preparation of the sample solutions via quantitative chemical analysis techniques.
- Preparation of calibrating solutions.
- Introduction or delivery of sample solution and calibrating solutions into the plasma.
- Appropriate measurement of the light intensities as per the precise analytical lines.
- Preparation of the calibration graphs for every element by analyzing the intensity of the emissions from the calibrating solutions.
- Determination of the concentration of the samples from calibration graphs.
The elemental concentration in the base sample is then further calculated by getting measurements of the elemental concentrations in the sample solution and dilution factor. Finally, the apparatus delivers precise results on the concentration of elements that were initially selected for measurement at the beginning of the process.
The ICP OES is one of the most important widely used techniques in the field of analytical chemistry with multiple applications across industries and in research work. However, the key to an accurate reading or measurement lies in the quality of the apparatus used. Hence it should always be sourced from a reliable vendor.