Patent ID: 8365576

Claim:
A method for detecting a low concentration gas contained in a measurand gas, the method comprising the steps of: supplying the measurand gas containing the target gas in a concentration of 50 ppm or less to an oscillation element, the oscillation element containing a quartz crystal resonator and a zeolite including a metal complex (hereinafter simply referred to as “metal-complex-including zeolite”) present on or above the quartz crystal resonator, and detecting the target gas through a change in resonance frequency of the quartz crystal resonator, the change caused by the adsorption of the target gas by the metal-complex-including zeolite, wherein the zeolite is selected from the group consisting of zeolite X, zeolite Y, EMT, SAPO-37, and beryllophosphate X having an internal pore diameter of 1.3 nm and a pore opening diameter of 0.7 nm, the metal complex is a metal phthalocyanine complex encapsulated in a unit cell of the zeolite, and the metal-complex-including zeolite is just supported on an electrode of the quartz crystal resonator.