Reduction of Reagent Blank Containing Trimethylamine Using Denuder Sampler Coated with Titanium Dioxide

Trimethylamine (TMA) is a compound with an unpleasant odor, like ammonia. We previously reported a detection system for trace TMA in ambient air by using a headspace gas-chromatography-surface ionization detector. In this study, a novel denuder sampler coated with titanium dioxide was developed. TMA, which was naturally contained in phosphoric acid used as a collecting solution, was photochemically decomposed by the denuder. Consequently, the denuder greatly reduced the TMA blank level. The detection limit of TMA was 0.004 ppbv for 60 L of an air sample. The analytical results of TMA in the lavatory showed good agreement with the values obtained by the bubbler sampling method.