Precautions for in-injection port thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) as applied to aerosol filter samples

摘要: In-injection port thermal desorption-gas chromatography/mass spectrometry (TD-GC/MS) allows for analysis >130 non-polar organic compounds on small quartz-fiber filter samples without extraction chemicals. TD-GC/MS has been applied to from long-term U.S. networks since it is cost effective and less labor intensive. However, of large numbers results in sensitivity reductions over time. Instrument reproducibility were examined after 100, 200, 500 sample analyses. Analyses standards between batches heavily loaded China Japan showed signal decreases 28–78% major classes. In the GC injection port, residues can accumulate gold-plated seal resulting analyte adsorption as well elevating background. Decreases in signal response 28–43% n-alkanes, 33–45% hopanes steranes, 28–56% PAHs, 38–78% phthalates when was not replaced Limits detection (LODs) also increased by 14–76% targeted compounds. Residues trapped capillary column head cause peak broadening overlap. The GC/MS system, including gold seal, (where eluted pre-concentrated), ion source should be cleaned every batch 50–100 samples.