A rapid method for the determination of sub-part per billion amounts of n-nitroso compounds in foodstuffs

Determination of dimethylnitrosamine in air and water by thermal energy analysis: validation of analytical procedures

“…DMN was identified here by both coincidence of retention time and by comparison of the quantitative amount present in both gas chromatography and high-performance liquid chromatography. Coincidence of retention time using gas-liquid chromatography (where the elution order is solubility/vapor pressure-dependent) and high-performance liquid chromatography (where the elution order is polarity-dependent) may be taken as confirmation of identity, particularly because the TEA detector that was used has been shown to be extraordinarily selective to N-nitroso compounds (7,10). In all cases, only one major peak was found to be present which corresponds in retention time to DMN; furthermore, the quantitative amount of DMN present was always identical by both the TEA-HPLC and TEA-GC techniques.…”

“…The development of a N-nitroso compound specific Thermal Energy Analyzer (TEA) has greatly simplified the analytical techniques because virtually no cleanup or concentration is required (6,7). With a selective catalyst the TEA pyrolyzer selectively cleaves N-nitroso compounds, splitting off the nitrosyl radical:…”

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

“…The use of permeation devices to generate calibration gas mixtures is a fairly widely used technique (1)(2)(3)(4)(5)(6)(7). Permeation, or effusion, of a compound through a membrane will occur at a constant rate if the ratio of the concentration of the compound on either side of the membrane is constant.…”

“…surement at the sub-microgram level in air, water, food, and other materials has been proposed (3)(4)(5). Since DMN can form from dimethylamine (DMA) and oxides of nitrogen (NO,), the apparent need to determine DMN in air near areas handling DMA has arisen.…”

Determination of N-nitrosodimethylamine in dimethylamine by gas chromatography with nitrogen selective detection and nitrosamine selective detection

“…Numerous methods have been reported for the analysis of -keto acids based on diverse principles. Among them the colorimetric method using 2,4-dinitrophenylhydrazine (1,2), UV absorptiometric (3)(4)(5) and the fluorometric (6, 7) methods coupled with enzymic reactions are most widely used. However, these spectrophotometric methods do not permit the simultaneous analysis of coexisting -keto acids.…”