A survey was conducted jointly by the Food and Drug Administration and the Department of Agriculture to ascertain the types and amounts of polycyclic aromatic hydrocarbons present in smoked foods. The samples include many varieties of meat products, poultry, fish, and other miscellaneous items. All samples were analyzed by the published methods of Howard et al. Results indicate that many smoked foods contain small amounts (0.5—7.0 ppb) of polycyclic aromatic hydrocarbons

A rapid method has been developed for the determination of N-nitrosopyrrolidine (NPYR) in fried bacon at less than the 1 ppb level. Ground fried bacon is mixed with anhydrous sodium sulfate and Celite by using a glass mortar and pestle. This dry mixture is then added to a chromatographic column containing a layer of acid-Celite. The column is washed with pentane-dichloromethane, and the nitrosamines are eluted with pure dichloromethane. The eluate is concentrated, and the nitrosamines are quantitated by using a gas chromatograph interfaced with a thermal energy analyzer. Recovery of the nitrosamine internal standard, N-nitrosoazetidine, added at the 10 ppb level, was over 90%. The results obtained by this method are in good agreement with the mineral oil distillation procedure currently used in the FSIS monitoring program. Because 25 samples can be analyzed per day per person, this simple screening procedure offers advantages over other methods.

Nine laboratories participated in a collaborative study of a method for determining 6 nitrosamines, dimethylnitrosamine, diethylnitrosamine, dibutylnitrosamine, nitrosopiperidine, nitrosopyrrolidine, and nitrosomorpholine, in the 5-17 ppb range. The coefficients of variation for repeatability were 10.8, 8.5,10.4, 8.5, 8.7, and 7.8% with corresponding coefficients of variation for reproducibility of 16.4, 12.0,13.6,10.8,11.2, and 10.3% and recoveries of 89.6, 91.6, 84.7, 90.0, 89.6, and 88.1%, respectively. The method was adopted official first action.

A rapid screening procedure for the detection of volatile N-nitrosamines in fried bacon has been developed for the regulatory monitoring of bacon. This procedure uses vacuum mineral oil distillation of an alkaline sample. The distillate is collected in a prewet trap immersed in liquid nitrogen. After thawing, the distillate is transferred to a separator. The trap is rinsed with methylene chloride which is then used to extract the nitrosamines. The methylene chloride is dried with Na2S04 and concentrated. A gas-liquid chromatograph coupled to a thermal energy analyzer is used to identify and quantitate the nitrosamines. Recoveries of 7 volatile N-nitrosamines added to 25 g fried bacon at the 10 ppb level (μg/kg) ranged from 78 to 92%.