Analytical MethodsMethod for sampling and analysis of volatile biomarkers in process gas from aerobic digestion of poultry carcasses using time-weighted average SPME and GC-MS

- Method uses retracted SPME fibers for passive gas sampling of hazardous processes.
- Method reduces risks when monitoring emissions from biohazardous waste treatment.
- Method accurately quantifies biomarker VOCs from animal tissue digestion process.
- SPME follows Fick's law; adsorption to SPME metallic parts does not affect accuracy.
- Method results agree with conventional active sorbent-based gas sampling.

A passive sampling method, using retracted solid-phase microextraction (SPME) - gas chromatography-mass spectrometry and time-weighted averaging, was developed and validated for tracking marker volatile organic compounds (VOCs) emitted during aerobic digestion of biohazardous animal tissue. The retracted SPME configuration protects the fragile fiber from buffeting by the process gas stream, and it requires less equipment and is potentially more biosecure than conventional active sampling methods. VOC concentrations predicted via a model based on Fick's first law of diffusion were within 6.6-12.3% of experimentally controlled values after accounting for VOC adsorption to the SPME fiber housing. Method detection limits for five marker VOCs ranged from 0.70 to 8.44 ppbv and were statistically equivalent (p > 0.05) to those for active sorbent-tube-based sampling. The sampling time of 30 min and fiber retraction of 5 mm were found to be optimal for the tissue digestion process.