Inexpensive analog equipment for processing gas chromatography mass spectrometry data.

Using relatively simple analog circuitry, and an inexpensive analog frequency modulated tape recorder (or a modified audio recorder) for data storage, repetitively scanned spectra may be examined on an oscilloscope, and reconstructed mass chromatograms produced. The same equipment may be used for peak matching, and for selective ion detection over the full mass range of a sector instrument.