The BTEX Calibration Kit (thermal desorption) was designed for the analysis of BTEX in urban environments followed by thermal desorption. The kit may be used for both routine calibration and quality control. The kit consists of twelve RAD145 Cartridge Adsorbents. Three of which are blanks and nine, divided into three concentration groups, are preloaded with BTEX to simulate 7 day exposures (100,080 minutes). Concentrations are described in the listed table. The values shown are indicative. Actual concentrations are certified for each lot. BTEX is spiked on the cartridges by injecting vaporized BTEX standards in methanol under nitrogen flow. A methanol peak may be visible during chromatographic analysis. The cartridges are stable for at least four months when stored at 4°C.