Temperature-programmed chemiluminescence measurements for discrimination and determination of fragrance

An analytical method using a cataluminescence (CTL)-based gas-sensor is proposed for determination and discrimination of fragrance vapors of lemon and orange, etc. CTL is a kind of chemiluminescence (CL) emitted during the catalytic oxidation of combustible gases. We found that the CTL-based gas-sensor made of γ-Al2O3 containing Dy2O3 is sensitive for fragrance substances of linalool, citral, limonene and α-pinene which belong to terpene. The intensity of the CTL in a heating course at a constant rate (CTL glow curve) shows specific profiles depending on the kind of these vapors. We can discriminate the type of these fragrance vapors by means of principal component analysis (PCA) of three characteristic parameters which reflect the CTL glow curve, i.e. two peak temperatures of the glow curve and half width of one of two glow bands. The concentration between 0.1 and 1 ppm of these vapors in air can be determined.