Method for sampling flue gas for analysis containing gas component having high susceptibility to adsorption

In relation to an automated flue gas measurement apparatus, a method for sampling an analyte flue gas containing a gas component having high adsorbability, characterized in that the method comprises:

• providing a gas sampling tube having a double-tube structure including an inner tube and an outer tube;
• causing a sampled gas to flow through the inner tube;
• injecting, into a space between the inner tube and the outer tube, a washing liquid for washing out a flue gas component deposited on a surface of the inner tube;
• introducing the washing liquid, through a small through hole provided at a position on the inner tube that faces the outer tube, into the inner tube through which flue gas passes;
• in a gas sampling mode, collecting the washing liquid in a flue gas absorption bottle using a flue gas suction pump disposed downstream of the gas sampling tube to thereby collect a predetermined amount of the flue gas component deposited on the surface of the gas sampling tube;
• and
• in a washing mode, operating a washing liquid pump so as to inject washing liquid only after collection of flue gas in the flue gas absorption bottle in the predetermined amount as determined by a gas meter.