page_title: Miniature mass spectrometer
section_title: Coupling and ionization in miniature mass spectrometer
hierarchical_section_title: Miniature mass spectrometer / Coupling and ionization in miniature mass spectrometer
caption_attribution_description: English: Microfluidic Chip fabricated in Glass. Channels are 50µm deep and 150µm wide.
context_page_description: A miniature mass spectrometer is a type of mass spectrometer which has small size and weight and can be understood as a portable or handheld device. Current lab-scale mass spectrometers however, usually weigh hundreds of pounds and can cost on the range from thousands to millions of dollars. One purpose of producing MMS is for in situ analysis. This in situ analysis can lead to much simpler mass spectrometer operation such that non-technical personnel like physicians at the bedside, firefighters in a burning factory, food safety inspectors in a warehouse, or airport security at airport checkpoints, etc. can analyze samples themselves saving the time, effort, and cost of having the sample run by a trained MS technician offsite. Although, reducing the size of MS can lead to a poorer performance of the instrument versus current analytical laboratory standards, MMS is designed to maintain sufficient resolutions, detection limits, accuracy, and especially the capability of automatic operation. These features are necessary for the specific in-situ applications of MMS mentioned above.
context_section_description: In typical mass spectrometry, MS is coupled with separation tools like gas chromatography, liquid chromatography or electrophoresis to reduce the effect of the matrix or background and improve the selectivity especially when the analytes are widely different in concentration. Sample preparation including sample collection, extraction, pre-separation increases the size of the mass analysis system and adds time and sophistication to the analysis. A lot of contribution promotes miniaturizing devices and simplifying the operations. A micro-GC has been implemented to fit to a portable MS system. Besides microfluidics is a competent candidate for MMS and automating sample preparation. In this technique, most of the steps for sample preparation are staged similarly with laboratory systems, but miniature chip-based devices are used with low consumption of sample and solvents. 
  One way to circumvent classical, lab-based sample introduction systems is the use of ambient ionization as it does not require mechanical or electrical coupling to a MMS and can generate ions in the open atmosphere without prior sample preparation. Different ambient ionization methods, including low-temperature plasma, paper spray, and extraction spray, have been demonstrated to be highly compatible with MMS.
  Without separation coupling, the basic building blocks in MMS, which are similar in composition with the conventional laboratory counterpart, are sample inlet, ionization source, mass analyzers, detector, vacuum system, instrument control and data acquisition system.
  Three most important components in MMS contributing to miniaturization are mass analyzer, vacuum system and electronics control system. Reducing the size of any components is beneficial to the miniaturization. However, it is noticeable that minimizing the analyzer’s size can greatly enhance the miniaturization of the other components especially the vacuum system because the analyzer is the pressure deciding factor for MS analysis and pressure interface fabrication.
caption: Microfluidic Chip iX-factory
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