| 摘要 |
PURPOSE:To enable efficient use of memory capacity, by providing a control system for variable setting the cycle of mass scanning according to the peak range of chromatogram so that the frequency of scanning will be almost the same with respect to any peak. CONSTITUTION:A gas chromatograph 1 is connected to a mass spectrometer (an ion source 3, an ion acceleration electrode 4, a total ion detector 5, a magnetic field 6 for mass spectrograph, an ion detector 7 or the like) through an interface 2. An excitation power source circuit 8 generates a saw-tooth current to run current to the magnetic field 6, where this cycle thereof is controlled with a computer (CP)9 at each one cycle of mass scanning. The CP9 samples the output of the detector 5 at a fixed cycle to obtain a differentiation signal of a chromatogram depending on the difference between adjacent sampling data. The CP9 also has the cycle of mass scanning set for the first peak of the chromatogram and the circuit 8 is controlled by the cycle. On the other hand, the CP9 counts the time from the start to the end of the mass scanning to determine the scanning cycle at the next peak. |
