Interlaboratory exercises for volatile organic compound determination

The results of a European level intercomparison involving measurements of 26 hydrocarbons (from C2 to C9) at ambient air concentration level are discussed. On-line sampling with cryo-GC-FID analysis was the most commonly used methodology among the 20 participating laboratories. The stability of the gas samples in the canisters; the calibration methodology, the separation of peaks and the low level of concentrations were identified as the most important factors, which contributed to the increase in the uncertainty of the measurement. Uncertainty values associated with the common method used for the quantification of each compound and exercise were also determined.