Dynamic reaction cell (DRC)

The collision reaction cell known by the trade name dynamic reaction cell (DRC) was introduced by Perkin-Elmer on their Elan DRC (followed by Elan DRC II and Elan DRC-e) instrument. The DRC is a chamber placed before the traditional quadrupole chamber of an ICP-MS device, for eliminating isobaric interferences. The chamber has a quadrupole and can be filled-up with reaction (or collision) gases (ammonia, methane, oxygen or hydrogen), with one gas type at a time or a mixture of two of them, which reacts with the introduced sample, eliminating some of the interference.

The DRC is characterized by the following parameters, that can be modified: RPq (the corresponding q parameter from the Mathieu equation), RPa (the corresponding a parameter from the Mathieu equation), which refer to the voltage applied to the quadrupole rods and the gas flow of the reaction gas.

Ammonia gas is the best solution for the majority of interferences, but it is far for being the perfect gas. Sometimes, for specific isotopes, other gas must be used for better results or even mathematical correction, if no gas offers a satisfactory advantage.