Patent ID: 7671329

Claim:
An inductively coupled plasma mass spectrometer designed such that an aerosol comprising a carrier gas and liquid drops containing an analysis sample is introduced into a plasma torch disposed near a work coil connected to a high-frequency power source, a plasma is generated such that it contains the ions of the elements contained in the aerosol, the plasma is projected toward interface having orifices, and at least some of the ions pass and escape through the orifices, said inductively coupled plasma mass spectrometer comprising: a control device for comprehensively controlling conditions of the inductively coupled plasma mass spectrometer according to instructions in a computer readable medium; the computer readable medium containing the instructions for instructing the control device to comprehensively control each of the following conditions: the amount of liquid drops in the aerosol, the flow rate of carrier gas in the aerosol, the RF output of the high-frequency power source, and the distance between the plasma torch and the interface, wherein the sensitivity to the ions to be measured can be set at a specific level by the control device and the ratio of the maximum and minimum sensitivities to the ions to be analyzed is at least 10:1; and wherein the computer readable medium further contains instructions for instructing the control device to determine at least the flow rate of carrier gas in the aerosol, the RF output of the high-frequency power source, and the distance between the plasma torch and the interface such that the points corresponding to the analysis conditions on a sensitivity/oxide ion ratio graph showing the relationship between sensitivity to a specific metal ion and oxide ions of the metal ion are positioned along an envelope wherein the log of the ratio of oxide ions forms a virtually proportional relationship with sensitivity when the oxide ion concentration at each sensitivity has been brought to virtually a minimum.