Many scientific publications (26, 27, 28) use the terms inductively coupled plasma optical emission spectroscopy (ICP-OES) and inductively coupled plasma atomic emission spectroscopy (ICP-AES) interchangeably. This is because both represent the emission of photons from an ionized sample that can be deconvoluted into signals from each of the constituent elements.
How do you analyze the data from an icp emission spectrometer experiment, and what can you learn from the results?
The general guidelines for the analysis of ICP-AES data state that you should look at the intensity of the light emitted at particular wavelengths and then compare that to the calibration data in order to determine the concentration of atoms that are emitted at that particular wavelength. The vast majority of instruments that are currently in use provide the user with the opportunity to select multiple wavelengths. When doing so, the user should select wavelengths that are in line with the emission signals coming from the atoms that are of particular interest.29Following the selection of the appropriate wavelength, the process of identifying the components contained within the sample is typically an automated one. Over the course of the past few years, this process has become increasingly sophisticated in order to facilitate multivariate analysis and highly sensitive identification.30
Other concerns that need to be addressed when analyzing ICP-OES data relate to the possibility of interferents and their ability to hinder the performance of the system. It is recommended to users that they use an internal standard in order to correct for variability from sample to sample and differences in the conditions under which samples are processed in order to eliminate unwanted interferences prior to analysis.31Scandium32 and yttrium33 are two elements that are frequently used as internal standards. These elements were selected due to the fact that their wavelengths generally do not overlap with those of other atoms in the sample. After the internal standards have been successfully implemented, the calibration data enables a direct comparison of the light intensity obtained from the sample to the light intensities of known sample compositions. This comparison provides the types of elements found in the sample as well as their relative ratios within that sample as the key readout data from the ICP-OES.
Typical line spectra generated by an ICP-OES instrument are shown on the left. The same spectra with an increase in magnification along the y-axis demonstrates that, despite being "lines" in the spectrum, they are still peaks and can, as a result, be affected by spectral interferences (right).
Line spectra that are typical for ICP-OES are shown on the left in Figure 2. The same spectra with an increase in magnification along the y-axis demonstrates that, despite being "lines" in the spectrum, they are still peaks and can, as a result, be affected by spectral interferences (right). Utilizing software that enables the selection of peaks that are unaffected by interference is one way to circumvent this challenge.
The benefits and drawbacks of the icp emission spectrometer method
The ability of the ICP-OES to identify the types of elements in complex samples as well as the ratios of those elements is one of its key strengths. ICP-OES, for instance, has been used successfully to analyze the composition of crude oil, contaminated soil, and heavy metal mixtures, all of which would have been difficult to analyze using other methods. This is because ICP-OES is a multi-step process. ICP-OES also has the ability to detect multiple elements at the same time, which is another significant advantage37, 38; researchers have reported instances in which ICP-OES has detected as many as 19 elements in a single analytical procedure.39The general applicability of ICP-OES has been improved thanks to advancements in spectral deconvolution41 and calibration procedures17, as well as improvements in the ability to aerosolize a wider variety of samples. These advancements were made to facilitate effective detection. ICP-AES can be used to determine the elemental composition of a sample, even when the sample in question is radioactive; however, separate measurements are required in order to determine the level of radioactivity present in the sample.42, 43In conclusion, the simplicity of the icp optical emission spectrometer has made it possible for it to be utilized in chemistry education settings,44 with solvents of both analytical reagent grade and spectral pure grade,45 and with relatively high throughput for sample preparation46 and analysis47, highlighting the ease with which the system can be utilized.
The requirement that samples be aerosolized is one of the most notable limitations of the ICP-OES. Despite the fact that the procedures for aerosolization have undergone significant advancements (refer to the section above for more information), this indicates that solid and liquid samples cannot be analyzed while they are still in their respective solid and liquid forms. In addition, Icp optical emission spectrometer is a destructive analytical method, which means that the sample cannot be retrieved after it has been analyzed. As a direct consequence of this, extremely valuable or scarce samples cannot be analyzed using this technique. In addition, developing a method with the use of ICP-OES can be a time-consuming process because it requires the completion of multiple steps:28(a) performing a rough analysis to obtain a general idea of the elements that are present in the sample; (b) selecting a wavelength based on that initial knowledge; (c) optimizing separation in such a way that signals from the various wavelengths have limited overlap; comparing the method and system performance with an internal standard to validate them; and conducting an analysis for spectral interferences and finding ways to eliminate those from the read-out without eliminating target signals. Lastly, requires expensive instrumentation for plasma generation, sample aerosolizing, and signal analysis, albeit at a relatively lower cost than other comparable methods such as ICP-MS,48 which means that access to this technique is necessarily limited.
Despite the fact that this technique has a relatively lower cost than other comparable methods such as ICP-MS,48 access to this technique is necessarily limited.