This note presents the automated determination of benzo[a] pyrene and benz[a]anthracene in tar distillation products by SPEGC/MS. Samples are dissolved in tetrahydrofuran (THF), placed in sample vials and internal standard added. The vials are then placed in the autosampler. All further sample preparation steps which include SPE cleanup on silica gel cartridges and injection into the GC/MS are performed automatically.

Eight replicates of each sample were analyzed resulting in relative standard deviations between 0.8 and 2.6 %. Analysis results were compared with results of an LC reference method with fluorescence detection [1]. Both methods gave equivalent results with maximum deviations of +6.7 and -11.3 % for benzo[a]pyrene.

These data show that the developed SPE-GC/MS analysis method is precise and accurate. The SPE system performs sample preparation during the chromatographic run of the preceding sample for maximum throughput, enabling the analysis of around 40 samples per day.