WHAT IS HIGH RESOLUTION INDUCTIVELY COUPLED PLASMA MASS SPECTROMETRY?

An inductively coupled plasma (ICP) is created using a radio frequency coil to turn a stream of argon gas into a high energy plasma. An ICP is an efficient means of generating ions from a sample aspirated into the plasma. Many labs today have an ICP emission spectrometer-a device that looks optically at the plasma to quantify elements present in the aspirated sample. These ICP emission spectrometers have detection limits in the ppm to ppb range, depending on the element.

Since 1984, ICP's have been coupled with mass spectrometers, which are one of the most sensitive ion analyzers/ detectors available. These ICP-MS instruments are becoming more commonly available. Most ICP-MS instruments utilize a quadrupole mass spectrometer and have a sensitivity in the low ppb range for many elements.

In the past few years a new type of ICP-MS has become available that utilizes a high resolution (i.e., double focusing, sector field) mass spectrometer: hence, high resolution inductively coupled plasma mass spectrometry or HR-ICP-MS. The high resolution mass spectrometer allows many interferences to be distinguished and in most cases provides detection limits in the parts-per-trillion (ppt) to parts-per-quadrillion (ppq) range. Many isotope ratios can be determined to better than ±0.1%.

Our workhorse: the Element 2 high resolution inductively coupled plasma mass spectrometer (HR-ICP-MS) from Finnigan MAT:

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