Modernization of vacuum subsystem of ICPMS using state-of-the-art technology

Inductively Coupled Plasma Mass Spectrometer (ICPMS) is a typical analytical instrument used for compositional characterization of materials up to the levels of parts per billion (ppb) and parts per trillion (ppt). ICPMS is a versatile, complex and a very sensitive analytical instrument. This instrument consists of various subsystems for performing its intended operation. Hence the availability of such an instrument depends on the reliability of its various sub-systems. Failure of any one sub-system will lead to the non-functioning of the instrument. High vacuum conditions of 10^-6 to 10^-8 mbar are needed in the mass analyzer region and detector region of the ICPMS for the efficient operation of the instrument. And ICPMS interlocks are designed in such a way that the mass spectrometer goes to "operate mode' only when the instrument parameters' sequence is maintained. Failure of any component in the vacuum subsystem leads to non-availability of the ICPMS. The manufacturer of the ICPMS integrated all the third party subsystems and their control signals into the customized interfacing circuits. Because of this customization, any failure of the third party component necessitates replacement with the same make and identical model. The ICPMS at NCCCM was procured in 1997, and due to obsolescence and embargo, the identical models are not available and in the event of failure of any component, the instrument had to remain inoperative. In this context, this paper focuses on the adoption of protocols needed for the upkeep of the mass spectrometry systems, need based design modifications and interfacing techniques for integrating vacuum subsystem components of different make. Various maintenance strategies implemented in maximizing the availability of ICPMS system are discussed at length in this paper