Gas analyzer

A gas analyzer for detecting a greenhouse gas contained in a sample gas, comprising:

• an adsorption-type column;
• a sample introduction unit that introduces said sample gas to one end of said adsorption-type column;
• an electron capture detector connected to the other end of said adsorption-type column;
• a detector gas supply unit that supplies nitrogen as a detector gas to said electron capture detector;
• a column oven that accommodates said adsorption-type column;
• a temperature control unit that adjusts the temperature inside said column oven;
• and
• a control unit that controls said temperature control unit such that, at the time said sample gas is introduced into said adsorption-type column, the temperature inside said column oven is lower than a first temperature, which is the upper limit of the temperature at which nitrous oxide is adsorbed in said adsorption-type column and does not desorb, and thereafter, the temperature inside said column oven is raised above said first temperature,
• wherein nitrous oxide is concentrated by adsorbing nitrous oxide in said adsorption-type column at a temperature equal to or lower than the first temperature and desorbing nitrous oxide from said adsorption-type column at a temperature above said first temperature.