The Reason for Vertical Return Peak in Gas Chromatography Analysis:

Oftentimes, the zero-point deviation of the gas chromatograph is improperly calibrated, leading to it falling outside the operational range of integrators or recorders, as well as chromatography workstations.

B. General integral meters or gas chromatography workstations have a narrower range of input voltage on the negative side. Some integral meters or recorders, as well as chromatography workstations, have an internal zeroing function and can perform forced zeroing.

If the zero point of the gas chromatograph deviates too much negatively from the integrator or recorder, or the chromatography workstation's own zero point, the aforementioned situation may occur. In this case, please re-zero the gas chromatograph before analysis.