A Guide To The Principle Of ICP-MS And Its Applications
Since its introduction, ICP Mass Spectrometry or ICP-MS has found usage in a wide variety of fields. For example, the semiconductor industry uses this method extensively for maintaining the quality of high-purity materials. Additionally, the icp ms instrument is also being used to maintain strict drainage and environmental standards, etc.
Defining ICP-MS
ICP stands for Inductively Coupled Plasma. ICP-MS is a method for chemical analysis that is flexible enough to be customized based on the demands and needs of the industry. Some industries where this method is used include exploration of natural resources, medical and pharmaceutical industry, nuclear and nanotechnology, materials and metallurgy, environmental and regulatory, etc.
In the simplest form, ICP-MS pumps a pre-prepared analyte-containing liquid through a nebulizer. This creates an aerosol that is further introduced into the argon gas plasma. The extremely high temperature of approximately 5500K to 6500K in the plasma is enough to enable the atomization and ionization of almost all elements irrespective of their ionization potential.
Electrostatic ion-optic elements further steer these analyte ions into the mass spectrometer where the ions are further separated basis their mass to charge or m/z ratio to enable their detection. Since ionization is 100% complete, the m/z ratio counts of ion detected are said to be the same as the concentration of the respective element in the analyte.
ICP-MS strengths and limitations
Some of the strengths of ICP-MS include:
· An ability to analyze mostly all periodic table elements,
· Even concentrations of elements that are very low in the ng/L range are detected,
· High sample throughput,
· 8 figure wide dynamic range,
· Low sample volumes produce the required results,
· Isotopes, both normal and radioactive, can be easily distinguished,
· Multi-element analysis can be simultaneously done.
Limitations of this method are mostly related to high equipment costs and the requirement of precision staff proficiency. Mass interferences sometimes pose a challenge but this can be easily tackled using appropriate methods.
Applications of ICP-MS
Some major applications of the ICP-MS include:
· In medicine and forensics: The use of the ICP-MS is rampant in this field, especially in toxicology. Several valid reasons prompt a physician to order for a metal assay like:
o Metabolic concerns,
o Hepatological issues,
o Heavy metal poisoning etc.
Each patient has a unique diagnostic plan. Thus, the samples sent for analysis are also patient-specific and can include anything from urine, plasma, whole blood, serum to packed RBCs.
In forensics, the ICP-MS is popularly used for glass analysis. Herein trace elements present on glass can also be detected and used to match crime scene samples to the suspect.
· In the environmental field: In this field, the use of ICP-MS is primarily related to the analysis of soil, water, etc. It is used to analyze the levels of contamination present, the degree of self-purification that water undergoes when flowing from one place to another, etc. Primarily the icp ms instrument is used to detect 8 elements that include Aluminium, Arsenic, Cadmium, Chromium, Lithium, Manganese, Antimony, and Zinc.
· In biological and industrial monitoring: In industries where workers have to be exposed to metals, like in the battery factory, the employers have to ensure that they undergo regular blood or urine tests using ICP-MS to check for toxicity.
· In geochemistry: In this field, it is essentially used for radiometric dating where the abundant presence of the different isotopes of Uranium and lead are analyzed.
· In flow cytometry: A new technique, based on the ICP-MS, has been introduced in this field as a replacement for the traditionally used fluorochromes for the labeling of antibodies or other such biological probes. The use of lanthanides in distinct combinations for antibody labeling makes it easy for ICP-MS to identify and quantitate it because of its distinct ICP footprint.
· In the pharmaceutical industry: This analytical method is extensively used to detect inorganic impurities present in the ingredients of the pharmaceuticals.
· In speciation analysis: This is a relatively recent and growing field. Speciation analysis is done using front-end chromatography separation and ICP-MS or AAS, both of which are elemental selective detectors.
There is a multitude of ways by which ICP MS is being used in diverse industries to benefit humanity. However, it would not be wrong to say that the full potential of the icp ms instrument is yet to be realized.
