About ICP

Elemental analysis has become an integral part of most scientific research.  Inductively Coupled Plasma (ICP) has grown to be an invaluable method by which an investigator may detect almost any analyte within the periodic table of the elements.  ICP utilizes an inductively coupled plasma source to de-solvate, atomize, and excite or ionize the sample. 

    Beside its ability to monitor multiple elements in a single reading, ICP also provides low detection limits, measuring at very low (ultra trace) concentration, depending on the instrument used.  Analyte detection by ICP is usually achieved via two methods; the first, utilizes a Mass Spectrometer (ICP-MS) that detects the various isotopes of each element while the second mode of detection makes use of a Charge Injection Device (CID) detecting elements by their multiple emission wavelengths (ICP-OES).

    ICP-MS is able to detect analytes at low part-per-trillion (PPT, pg/ml) concentrations.  As in all mass spectrometers, molecules / elements are separated according to their mass/charge ratio.  Newer instruments utilize  hexa/octapole collision cells which eliminate or significantly minimize poly-atomic interferences such as the infamous ArO⁺ interference at mass 56 which is the mass of the most abundant isotope of iron (Fe-56). 

    ICP-OES sensitivity is at the low part-per-billion (PPB, ng/ml) range.  After electron excitation, that is achieved by the plasma, an atom will emit electromagnetic radiation as the electron relaxes to the lower energy ground state.  That photon/s (hν) is/are directed by a series of optics leading to the CID detector.  The TJA IRIS 1000's CID is an array of 512X512 pixels of continuous wavelength detector.  That means that the entire chip is photoreactive and thus enables the ICP-OES to detect the various emission lines with great accuracy.