ICP-MS at MURR
Inductively Coupled Plasma Mass Spectrometry (ICP-MS) is a very powerful tool for trace (ppb-ppm) and ultra-trace (ppq-ppb) elemental analysis. ICP-MS is rapidly becoming the technique of choice in many analytical laboratories for the accurate and precise measurements needed for today's demanding applications. In ICP-MS, a plasma or gas consisting of ions, electrons and neutral particles, is formed from argon gas. The plasma is used to atomize and ionize the elements in a sample. The resulting ions are then passed through a series of apertures (cones) into the high vacuum mass analyzer. The isotopes of the elements are identified by thier mass-to-charge ratio (m/e) and the intensity of a specific peak in the mass spectrum is proportional to the amount of that isotope (element) in the original sample.
The following pages describe the instrument and the techniques:
- Creating the Ions The inductively-coupled plasma is a very aggressive ion source...
- Sampling the Ions A special set of metal cones and ion-focusing elements are used to extract the charged atoms from the plasma...
- Analysis Methods At MURR we have a choice of two ICP analysis methods.
- Comparisons of Techniques
Quadrupole ICP-MS is able to differentiate easily between the different isotopes of a single element or between one element and another of differing mass.
High-Resolution ICP-MS is able to resolve most isotopes from any molecular species that would otherwise interfere with their analysis.
- The Analysis: Calibration Any sample entered into the mass spectrometer under exactly the same conditions will return a count rate, which can be converted directly to concentration for each element from a calibration curve.