Gas Chromatography and Selective Detection of N-Nitrosamines

N-Nitrosodimethylamine in fish meal

“…The tic method (Sen et al, 1969) with the double-spray technique is very specific for A-nitrosamines, but additional confirmation is necessary for unequivocal proof of the identity. Recent studies by Rhoades and Johnson (1970) indicated that amines and certain dilakylnitrosamines can be selectively detected by glc analysis using a Coulson electrolytic conductivity detector operating in the pyrolytic mode. If free amines and other basic compounds are removed by an acid wash of the extract (as was done in this study) the technique then becomes more selective and detects only nitrosamines and other neutral compounds which produce amines upon pyrolysis.…”

“…Further purification was achieved by chromatography on a basic alumina column. Finally, DMN was detected and semiquantitatively estimated by thin-layer chromatography (tic) and gas-liquid chromatography (glc) using a Coulson electrolytic conductivity detector (Rhoades and Johnson, 1970). Final confirmation was carried out by glc-mass spectrometry.…”

Automatic Colorimetric Determination of -Nitroso Compounds

“…This is also the approximate sample concentration required for gas chromatographic analysis with a flame ionization detector (Issenberg, 1971), although the total volume of sample required for gc may be five times less. The selective gc detector of Rhoades and Johnson (1970) would provide even more sensitivity at a lower background noise level. Although a range-expander on the recorder could increase the sensitivity of our analyzer, in practice it is the signal/noise ratio that establishes the actual detection limit.…”

“…The most specific, sensitive, and quantitive methods available are those which utilize gas chromatography (gc) and mass spectrometry after a suitable cleanup procedure (Howard et al, 1970); the possibility also exists for highly specific gc detectors (Rhoades and Johnson, 1970). These methods, however, are tedious and are applicable only to volatile compounds.…”

Determination of nitrosodimethylamine in the low parts per billion

“…Mayerhofer and Moehler (1967) and Sen et al (1969) used these techniques to determine nitrosodimethylamine (NDMA) and nitrosodiethylamine in food. Rhoades and Johnson (1970) selectively pyrolysed N-nitrosamines to ammonia at 400-600°C. Howard et al (1970) extracted NDMA from smoked fish and detected it by a gas chromatograph equipped with a modified thermionic detector.…”