Data processing system by computer for GC/MS, (1)

The full automatic system including data acquisition and processing for GC/MS was constructed, and its applicability was studied. The mass spectrometer(Hitachi RMU 6-E single-focusing)and a small computer(JEOL JEC-5)with 4 k words of 16-bit length and with a 2-channel 8-bit A-D converter were adopted. So as to scan successively and automatically, GC/MS was partially modified by introducing the meter relay units and a solenoid valve. The electric out-put of mass spectrometer is digitized at a rote of 4500 points per sec. while the spectrometer scans in the range m/e 0-600 in 5 sec., and the data are punched out immediately as a tape in a few sec. in order to save core memory. The computer reads the tape, calculates m/e values, normalizes the intensities, and prints out the mass spectra in digital form. M/e values were correct up to 300, and the pattern coefficient was quite similar to that of the visicorder, and these values were suitable for further processing such as searching the standard files of mass spectra. This system with automatic scanner enables us a full automatic data reduction for GC/MS method.