Sorbent-based active sampling method for the simultaneous analysis of very volatile, volatile, and semi-volatile organic compounds

A thermal desorption gas chromatography-mass spectrometry (TD-GC/MS) method is presented that combines a novel sorbent configuration (Carbograph 5TD and Carbosieve™ SII) with two capillary columns connected in series: a porous layer open tubular (PLOT) column for very volatile organic compounds (VVOCs) and a conventional column for volatile and semi-volatile organic compounds (VOCs and SVOCs). The method addresses the lack of a standardised approach for the simultaneous determination of VVOCs, VOCs, and SVOCs in indoor air within a single analytical run. Validation using a mixture of 69 compounds demonstrated high precision, excellent linearity, and low limits of quantification (LoQs). Repeated measurements yielded coefficients of variation below 10% for most analytes. Across calibration ranges from below 1 ng to above 200 ng, coefficients of determination (R²) exceeded 0.99 for almost all compounds. Based on a sampling volume of 1 L, LoQs were below 10 µg m^-3 for 76% of analytes and were comparable to or lower than literature values. Humidity effects were most pronounced for highly polar compounds but were less influential than PLOT column length. A 3 m PLOT column enabled analysis of the entire analyte range in a single run, albeit with reduced chromatographic resolution. This limitation was largely mitigated by evaluating characteristic target ions. Extending the PLOT column to 6 m substantially improved resolution but decreased sensitivity for SVOCs. The optimum column configuration therefore depends on the analytical objective. The proposed method enables simultaneous characterisation of indoor air contaminants across a broad volatility range and may improve the efficiency and cost-effectiveness of emission testing and indoor air investigations.