ICP Analysis

Inductively coupled plasma mass spectrometry (ICP-MS) combines the easy sample introduction and quick analysis of ICP technology with the accurate and low detection limits of a mass spectrometer. This ICP analysis method exhibits high sensitivity and can perform multi-element analysis, often at the parts-per-trillion level. It is capable of the determination of a range of metals and several non-metals.

Samples are decomposed to neutral elements in a high-temperature argon plasma to produce ions and are analyzed based on their mass-to-charge ratios. Aqueous samples form by way of a nebulizer which aspirates the sample with high-velocity argon, forming a fine mist. The aerosol then passes into a spray chamber for removal. Droplets small enough to vaporize in the plasma torch pass into the torch body, where the aerosol mixes with more argon gas. A coupling coil transmits a radio frequency to the heated argon gas, producing an argon plasma at the torch. The hot plasma removes any remaining solvent and causes sample atomization followed by ionization.

We’ve enhanced our trace elemental analysis capabilities by adding a high-resolution inductively coupled plasma (ICP) quadrupole mass spectrometer for ICP-MS. The mass spectrometer allows routine chemical testing for trace elements in superalloys. It provides ultra-trace elemental analysis for high-purity alloys like those in the semiconductor industry. The ICP-MS spectrometer increases the capacity for chemical elemental analysis of samples into the parts per trillion range.

LTI performs both types of ICP analysis with computer-controlled spectrometers. Computer software controls and monitors the instrument functions, then processes and stores data before outputting the results of the ICP test. The spectrometers use charge-coupled device (CCD) technology, allowing the instruments to measure the broad spectrum of elements.

ICP metal analysis is performable on solid and liquid samples. However, a solid sample must be converted to liquid form before testing by dissolving the sample in a solvent (typically acid) to produce a solution. The sample solution enters the ICP as a fine aerosol of droplets—the aerosol forms from a nebulizer which aspirates the sample with high-velocity argon to form a fine mist.

The aerosol then passes into a spray chamber to remove larger droplets. Droplets small enough to be vaporized in the plasma torch pass into the torch body, where the aerosol mixes with more argon gas. A coupling coil transmits a radio frequency to the heated argon gas, producing an argon plasma in the torch. The hot plasma dries any remaining solvent and causes sample atomization.

The ICP-AES spectrometer detects the atomic emissions produced as light. With ICP mass spectrometry, the process uses ionization. The resulting mass of the ions indicates the elements present in the sample.