Cold plasma is not the technique. It is rather a condition of the plasma. This condition used to be used for determination of the elements  like Ca, K, etc. that are interfered by argon not only in the Thermo designs but also in the instruments of other manufacturers. It uses the phenomenon that these elements have lower first ionization energy than argon so the power of the plasma is lowered significantly that it manages to ionize these elements but not argon. As far as I know it might be used for the determination of Ca in trace concentrations in semiconductor for example.  Nowadays it has been limited by the introduction of collision and reaction chambers of different kinds, which allow to remove interferences with higher efficiency than cold plasma conditions and at the same time do not create other analytical problems that cold plasma condition can cause eg.: lower plasma temperature that can cause severe matrix effect.