A Peltier-effect cryogenic trap was developed that consisted of a polytetrafluoroethylene (PTFE) body sandwiched by two Peltier modules. In the body, a zigzag channel was cut; near the exit of which a sorbent bed of 0.2 g Chromosorb sorbent was embedded. After the trap was precooled, the arsines flew along the channel. CH3AsH2 and (CH3)2AsH were selectively trapped by the sorbent bed while AsH3 passed the trap unaffected and was finally quantified by atomic fluorescence spectrometry. This approach eliminated liquid nitrogen (LN2) as the conventional coolant and allowed continuous AsH3 detection leading to enhanced sample throughput. For inorganic As, limit of detection (LOD) was 1.1 ng/g and recovery was 101.0±1.1% at 100 ng/g. Monomethylarsonic acid and dimethylarsinic acid did not interfere with 0.2±1.2% and -0.3±0.5% recoveries, respectively.

Determination of inorganic arsenic in rice by hydride generation, Peltier-effect cryogenic trapping and atomic fluorescence spectrometry

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.