The Complete Guide to Fundamentals of ICP-MS and How it Works
The ICP-MS technique is widely used in several fields for better quality control of most materials with high purity and trace hazardous metal amounts. This analysis can respond well to stricter and improved drainage and environmental standards. With these key features, the ICP-MS technique paves its way in various laboratories, making it one of the most common and popular efficient analyzing techniques in various research areas. In this article, let’s learn about the fundamentals of ICP-MS, its components, and how it works.
What is ICP-MS?
ICP-MS, or Inductively Coupled Plasma Mass Spectrometry, is a famous analytical technique for measuring and identifying specific elements within a sample through ionization. The mass spectrometer is responsible for separating the ions in their mass: charge ratio after being examined in the ICP.
To determine the amount and concentration of the chosen element, the detector counts how many ions are selected per second. ICP-MS requires the samples to be liquified, so solid and biological samples should be digested before their analyses.
When the sample is converted to liquid, the plasma utilizes Argon carrier gas, aerosolizing the sample. It only allows small and fine droplets to enter the chamber directly into the Argon plasma torch. When the Argon plasma desolvates and ionizes the sample, ions are extracted through interference and skimmer cones from the plasma.
These ions are separated according to their mass-to-charge ratios. Only selected ions can travel to the detector, where they are measured according to their concentration and counts per second by ICP-MS instruments.
Components of ICP-MS
ICP-MS can ionize almost every element in the periodic table. Generally, ICP-MS has six major components:
- Sample introduction system
- Inductively coupled plasma
- Interface
- Ion optics
- Mass analyzer
- Detector
The first requirement for ICP-MS analyzing technique is the sample should be in liquid form. These liquid samples undergo nebulization in the instrument’s sample introduction system, creating fine droplets of aerosol that will enter the argon plasma.
Additionally, these droplets are then atomized and ionized in the high-temperature plasma, and they are extracted from the interface region to enter the ion optics, which are electrostatic lenses. These ion optics are used to focus and guide the ion beams to enter the quadrupole mass analyzer, where they will be separated depending on these ions’ mass-to-charge ratio. Afterwhich, the detector measures them.
Applications of ICP-MS
Aside from scientific research, ICP-MS has evolved to involve other fields such as environmental safety, bio-remediation, maintenance of food quality control, diagnostic laboratories, and chemical and biological investigations. Because of the benefits of this analyzing technique, it has also been used widely in petrochemical, geological, technological, and environmental studies.
The ICP-MS analyzing technique is easy and efficient, and most chemistry education contexts have also started to employ this method for sample analyses. Recently, studies have also started to apply ICP-MS instruments in analyzing and determining trace amounts of inorganic impurities in pharmaceuticals and drugs.
Benefits of ICP-MS
The following are essential benefits that make ICP-MS one of the famous sample analyzing techniques in various fields:
- Multi-element technique with low detection limit and large analytical range
- High sample throughput and low sample volume
- It’s easy to prepare the samples analyzed
- Contain tandem mass and high-resolution spectrometry
- Allow efficient and premium interference level
- Rapid identification of a sample’s quality and quantity
- Allows comparison of isotopes
Another major advantage of ICP-MS is its suitability and effectiveness as a selective online detector to determine element species. This led to this technique gaining popularity in biological sciences and food toxicology.
The ICP-MS technique is also versatile, allowing accurate connectivity with various sample introduction systems, such as electrothermal vaporization, nebulization, chemical gas generation, laser ablation, and liquid chromatography.
Disadvantages of ICP-MS
On the other hand, this technique also has disadvantages you should be aware of before utilizing this technique:
- The equipment and Argon operating costs can be expensive.
- It requires multiple gases with high purity.
- The staff operating the equipment should be well-trained.
- There is a need to control the interference.
- Setting up the laboratory for HEPA filters, air-conditioning, and dust reduction measures is costly.
The Future of ICP-MS
ICP-MS has proven its effectiveness and accuracy in various fields, and more researchers are continuously employing this technique, improving everyone’s quality of life.