抄録
A new twin ion source mass spectrometer has been constructed for the application of simultaneous meaurement of respiratory and blood gases. The ion optics is such that two ion beams of same m/z from two ion sources are analyzed through a common magnetic field and are simultaneously received by the respective collectors. The gases measured are CO2, N2O, Ar, O2, N2, and C2H2, and they are detected on 44, 40, 32, 30, 28, and 26 (a,m,u). The ions are measured by multi-ion detection system which consists of amplifiers and integrators for the ion peak detection, sample-holders which separate and hold the peaks, the microcomputer (8085 CPU) with its interface, and of the molecular peak calculator. For the respiratory gas analysis, automatic calibration is carried out. The computer system is employed to determine and produce the scanning voltages and to control the integrators and sample-holders.
The spectra from two ion sources are proved to be perfectly resolved with all scanning volteges on the respective collectors. Mixing of the samples between two sources is of the rate of 1/30 and compensated by the analogue circuit with satisfactory precision.
Thus the simultaneous measurement was carried out within the error of 0.05% to the full scale for the respiratory gases, and within the error of 0.2 Torr CO2 and 0.5 Torr O2 respectively, for 76 Torr blood gases.
