A solid-phase micro extraction (SPME) device comprises a supporting substrate (10) in the form of a sheet of paper board, of cardboard or of plastics material having first and second major surfaces (11, 13) and first and second end regions. A layer (12) of gas barrier material is applied over the first end region of a least the first major surface (11). A volatile compound sorptive coating (14) is disposed on the gas barrier material on the first major surface (11). This may be on only a portion of the layer of gas barrier material (12), such as a central region of the first end region of the first major surface (11) where a depression or indentation (15) may be formed for this purpose. The second end region of the substrate (10) is dimensioned to serve as a handhold section (16) of the device. This SPME device may be used in combination with a breath sampler in the form of a hollow container, the SPME device being removably mounted to the breath sampler with the first end region of the SPME device protruding through a slot into the chamber of the sampler while the handhold section of said SPME device remains predominantly outside to facilitate rotation of said inner tubular part of the sampler from an open to a closed disposition. This SMPE device may also be used in combination with desorption apparatus having heating means for heating surface regions flanking the sorptive coating sufficient to release volatile substances therefrom.L'invention concerne un dispositif de micro-extraction en phase solide (SPME) qui comprend un substrat de support (10) en forme de feuille de carton ou de matière plastique ayant des première et seconde surfaces principales (11, 13) et des première et seconde régions d'extrémité. Une couche (12) de matériau étanche aux gaz est appliquée sur la première région d'extrémité d'au moins la première surface principale (11). Un revêtement (14) de sorption de composé volatil est disposé sur le matériau étanche aux gaz sur la première surface pr
