How Do ICP MS instruments Work?

Inductively coupled plasma mass spectrometry offers non-destructive, real-time analysis through the separation of ions in a plasma. Keep reading to learn about its features, applications, ways to calibrate it, and how it works.

What Are the Features of the ICP-MS Instrument?

Inductively coupled plasma mass spectrometry (ICP-MS) is an analytical technique used to detect trace metals. It allows the simultaneous determination of up to 70 elements in a sample.

The method has extremely high sensitivity, allowing even parts per trillion (ppt) levels to be measured with the proper instrumentation.

Here are the features of ICP MS instruments.

1. High Sensitivity

An instrument with high sensitivity is required to detect trace elements like mercury, lead, arsenic, cadmium, and selenium. These elements are present in very low concentrations of parts per billion or even parts per trillion in real-world samples.

2. Multielement Capability

With the recent advancement in ICP-MS technology and new software development, detecting all elements in one run is now possible. This dramatically reduces the analysis time and improves laboratory efficiency.

The multielement capability is especially useful in industries where trace elements and major element analysis are required, such as food safety, environmental, pharmaceuticals, and materials.

3. Wide Linear Dynamic Range

The wide linear dynamic range is a particular feature of ICP-MS. This is advantageous because the low detection limit can detect trace elements, while the high limit can be used to detect heavy metals.

What Are the Applications of the ICP-MS Instrument?

The ICP-MS instrument has a wide range of applications in different fields. Generally, the main applications are listed below.

1. Food Quality Control

The main task of food quality control is to ensure that there are no harmful heavy metals in the food. ICP-MS is a powerful tool for this task: it can simultaneously analyze more than 70 elements, including heavy metals such as lead, cadmium, mercury, arsenic, and chromium.

2. Trace Analysis

Making multiple determinations of trace elements in the same sample is often necessary. This can be done very efficiently by using the continuous introduction capability of ICP-MS.

3. Quality Control

ICP-MS is an excellent tool for quality control in biological and medical samples. Biological materials are analyzed by digestion before ICP-MS analysis.

Many elements can be measured simultaneously, making this technique very useful for tracking trace elements in tissue samples and correlating them with experimental results.

How Do ICP-MS Instruments work?

It works by ionizing a sample using a high-temperature plasma such as argon. This process separates the ions of different masses. A mass analyzer then sorts the ions according to their mass-to-charge ratio. Lastly, the detector determines the number of selected ions every second, allowing the instrument to identify each element’s concentration.

How to Calibrate an ICP-MS Instrument?

Inductively coupled plasma mass spectrometry is a powerful technique for determining metals and some nonmetals in a sample.

To obtain accurate results from an ICP-MS instrument, it is important to ensure that it is properly calibrated. The calibration methods for an ICP-MS instrument include:

1. External Calibration

In the external calibration technique, calibration standards with known concentrations of elements are analyzed, and a calibration curve is constructed. 

In subsequent analyses, unknown samples are also analyzed, and their concentrations are determined by comparison with the calibration curve.

2. Isotope Dilution

Isotope dilution is a technique applicable to the quantitation of most analytes using ICP-MS. The analyte is added to the sample in known concentration. This addition is made as an isotopic abundance of the analyte.

After the analysis, the results are corrected by comparing the measured isotopic abundance ratio of the sample to that of the isotopic standard. This correction compensates for errors in instrument response and sample preparation.

3. Compound-Independent Calibration

The technique of compound-independent calibration involves calibrating one element’s chemical species and utilizing another as a calibrant. This technique can significantly reduce the need for internal standardization in many applications. 

Compound-independent calibration is useful when internal standards cannot be added to the sample or when they are not available.

Wrapping Up

When it comes to modern science, ICP-MS is one of the most powerful tools available. If you need to measure trace elements in samples, there’s no better way to do it without spending time and resources than with this instrument.

References

https://www.thermofisher.com/ph/en/home/industrial/spectroscopy-elemental-isotope-analysis/spectroscopy-elemental-isotope-analysis-learning-center/trace-elemental-analysis-tea-information/inductively-coupled-plasma-mass-spectrometry-icp-ms-information.html

https://www.sciencedirect.com/topics/neuroscience/inductively-coupled-plasma-mass-spectrometry

https://www.news-medical.net/whitepaper/20170905/Benefits-and-Uses-of-IC-ICPMS-Method.aspx

https://www.ohsu.edu/elemental-analysis-core/icp-ms-technique#:~:text=Mass%20Spectrometer%20(MS)%20separates%20the,concentration%20of%20each%20chosen%20element.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6719745/

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