Evaluation of thermal desorption analysis on a portable GC–MS system

The HAPSITE-ER-TD (Hazardous Air Pollutants on Site Extended Range HAPSITE-ER) portable gas chromatograph–mass spectrometer (GC–MS) combines the sensitivity of a thermal desorption (TD) GC–MS with the advantages of field-portable instrumentation. Though previous iterations of the HAPSITE have been extensively evaluated in the literature, performance assessment of the TD-equipped instrument is lacking. In this manuscript, the variability in the HAPSITE-ER-TD response was established for both internal standards and test compounds across three instruments over a 5-week time course. These data show poor normalised internal standard reproducibility with %RSD values from 17.84% to 49.97% on the HAPSITE-ER-TD when compared to a bench-top instrument (%RSD p value = 0.0014) compound-dependent system carryover on the HAPSITE-ER-TD, indicating that procedural modifications to eliminate instrumental carryover may be necessary. This study establishes several limitations associated with the use of the HAPSITE-ER TD accessory with suggestions for addressing the shortcomings to allow for reliable field use.