inductively coupled plasma ICP

A Plasma is a gas that contains ions and free electrons.

electrically conductive so that it responds strongly to electromagnetic fields.

argon

an electrical discharge

through inductive coupling of free electrons with rapidly oscillating external magnetic field (27 MHz) Energy is transferred collisionally to Argon molecules

allows very high temperatures ~ 10000 C (a low pressure plasma is a fluorescent lamp)

between 6 000 K and 10 000 K

inert not expensive obtained at high purity

first ionization potential of 15.75 eV • Higher than the first ionization potential of most other elements (except He, F and Ne) • Lower than the second ionization potential of most other elements (except Ca, Sr, Ba…)

because the plasma environment is defined by Ar

it creates a time varying magnetic field around it,

electric currents in the rarefied gas, leading to break down and formation of a plasma. - ICP discharges are of relatively high electron density, on the order of 1015 cm-3.

ICP - MS : Inductively Coupled Plasma Mass Spectroscopy ICP - OES : Inductively Coupled Plasma Optical Emission Spectrometry = ICP - AES : Inductively Coupled Plasma Atomic Emission Spectrometry

bulk elemental chemical analysis of just about any material or substance (waters, biological materials, inorganic materials of all sorts, environmental, forensic, geological samples…

most of the periodic table conc. from major to parts per billion or in cases parts per trillion in solution can be measured

to produce excited atoms that emit electromagnetic radiation at a wavelength characteristic of a particular element.

the concentration of the element within the sample.

coupling together an ICP as a method of producing ions with a mass spectrometer as a method of separating and detecting the ions.

quantitative multi-elemental analysis and stable isotopic ratioing that is becoming increasingly important in biotechnology, nanotechnology, biochemistry and analytical chemistry.

 Excellent detection limit low ppb-ppt for all elements  Wide elemental coverage from Li to U, over 70 elements measurable  All elements determined simultaneously  Wide dynamic range linear over 9 orders  Routine technique can leave system running overnight  Small size instrument saves space in the lab

MS much simpler than the optical emission spectra. Most heavy elements exhibit hundreds of emission lines, but they have only 1-10 natural isotopes in the mass spectrum.  ICP-OES suffers from many overlapping spectral interferences from other elements and a very high background emission from the plasma itself, limiting detection limits.  Detection limits of ICP-MS are three orders of magnitude better than ICP-OES.