CERTIFICATION OF A REFERENCE MATERIAL FOR AROMATIC-HYDROCARBONS IN TENAX SAMPLERS

A homogeneous and stable reference material consisting of aromatic hydrocarbons sorbed on Tenax in stainless-steel sample tubes has been prepared and certified. An initial feasibility trial established that a homogeneous and stable batch could be prepared. Part of this batch was used in an intercomparison, which allowed the identification of various sources of error. A second test batch was used in a second intercomparison in an attempt to improve the analytical performance of the participating laboratories. A third batch (of 1000 tubes) was then prepared and certified on the basis of analyses carried out in ten laboratories. The certified values for benzene, toluene and m-xylene are, respectively, 1.053 +/- 0.014, 1.125 +/- 0.015 and 1.043 +/- 0.015-mu-g per tube. This Community Bureau of Reference (BCR) Certified Reference Material 112 is recommended for quality control and for calibration purposes.