Determination of sub-microgram per cubic meter levels of N-nitrosodimethylamine in air

Abstract

Ambient-temperature caustic impinger traps were used in parallel sampling with cryogenic caustic traps to study the degree of conversion of dimethylamine (DMA) to A/-nitrosodimethylamine (DMN) when DMA and NO" were brought together by trapping. Under simulated use conditions where DMA at sub-ppm (0.05) and NO, (0.2 ppm) from light traffic were brought together by trapping, the cryogenic traps produced from one to two orders of magnitude more DMN than the ambient traps. For routinely measuring DMN in air, ambient trapping in caustic followed by combination gas chromatography-mass spectrometry readout has been shown to produce artifact-free results.Recent literature reports have expressed concern that N-nitrosodimethylamine (DMN) may be a widespread environmental contaminant which may have implications as a human carcinogen (1, 2). The necessity for DMN mea-

Sampling of organic compounds in the presence of reactive inorganic gases with Tenax GC

“…There is, however, a paucity of experimental research addressing the question of whether decomposition products or artifacts occur during the collection of vapor-phase organics. Isolated reports do suggest that serious problems could exist with cryogenic traps (13)(14)(15), containers (11,16) and sorbent traps (17). With the observation of nitrosamines in ambient air, the potential in situ formation of these substances from secondary amines and nitrogen oxides was of some concern in cryogenic traps (13,14) and on sorbents (17,18).…”

“…Isolated reports do suggest that serious problems could exist with cryogenic traps (13)(14)(15), containers (11,16) and sorbent traps (17). With the observation of nitrosamines in ambient air, the potential in situ formation of these substances from secondary amines and nitrogen oxides was of some concern in cryogenic traps (13,14) and on sorbents (17,18). In fact, a metamorphosis of collection methods for nitrosamines occurred leading eventually to a sorbent cartridge impregnated with sulfamic acid to inhibit nitrosation (18).…”