Agilent 8800 Triple Quadrupole ICP-MS: Understanding oxygen reaction mode in ICP-MS/MS

The use of oxygen as a reaction gas for the removal of interferences in quadrupole ICP-MS is well established. However, prior to the development of the Agilent 8800 Triple Quadrupole ICP-MS (ICP-QQQ), the use of oxygen had been limited to determination of a small number of analytes in simple, well defined matrices. This is because oxygen can react with matrix components, analytes and polyatomic species in the cell resulting in the formation of new and unwanted interferences and loss of analyte. In order for oxygen reaction mode to be used reliably, the reaction environment within the cell must be strictly controlled. To this end, the Agilent 8800 ICP-QQQ employs an additional quadrupole mass filter before the reaction cell. This additional quadrupole (Q1) can be used to accurately control the species that enter the cell before any reactions can occur, resulting in precise control of the reaction chemistry even in the case of unknown or complex matrices. The use of an additional mass filter before the cell is refered to as MS/MS mode, and is currently only possible using ICP-QQQ. The use of MS/MS mode with ICP-QQQ permits reaction chemistry to be applied to the most complex Agilent 8800 ICP-QQQ