The combination of micro reactor and analytical devices are popular in research and industry, in addition to the automation of analytical tasks. An automated system for online reaction monitoring in a micro reactor using a mass spectrometer has therefore been realized. The system offers fast data acquisition at discrete time-point in a reaction process. In addition, different functions and utilities that facilitate the convenience to users are included: A dilution module, integration of the micro reactor system to an ICP-MS, two sampling methods, a heating module and a control software.