Pressure control valve and supercritical fluid chromatograph

A supercritical fluid chromatograph comprising:

• an analysis channel;
• a mobile phase liquid delivery portion for delivering a mobile phase to the analysis channel;
• a sample introduction portion for introducing a sample into the analysis channel;
• a separation column arranged on a downstream side of the sample introduction portion on the analysis channel;
• a detector arranged on a downstream side of the separation column on the analysis channel and detecting a sample component separated by the separation column;
• and
• a pressure control valve, arranged on a downstream side of the detector on the analysis channel and controlling a pressure in the analysis channel to a pressure at which the mobile phase is in a supercritical state, further comprising:
• a pressure control block having an opening portion provided on one outer surface, a pressure control surface provided as a plane at a bottom portion of the opening portion, and two internal channels having openings at respective end portions of the pressure control surface;
• a sheet-like valve body having elasticity and arranged so as to cover the pressure control surface;
• and
• a valve body driving portion provided on a side opposite to the pressure control surface with the valve body interposed therebetween, wherein the valve body driving portion is driven in a direction perpendicular to the pressure control surface so that an amount of a gap between the valve body and the pressure control surface is adjusted by pressing the valve body in the direction perpendicular to the pressure control surface, wherein
• the pressure control surface is made of a material having higher hardness than the hardness of SUS316L.