No abstract

Four composite diets from three cities, each representing the daily per capita consumption of foods in Canada, contained on analysis 191, 220, 113, and 150 mug selenium. Cereals provided the most selenium (62-112 mug) followed by meat, poultry, and fish (25-90 mug) and dairy products (5-25 mug). The average daily intake of selenium in Canada was also calculated from published analytical data and the per capita disappearance of unprepared foods. The total intake was 197 mug/day, and the major sources were wheat flour (98 mug), pork (21 mug), poultry products (24 mug), and fish (17 mug). Because the average diet is rich in selenium, the possibility of a deficiency in the adult is considered to be remote. Milk is relatively low in selenium, and thus the greatest deprivation in humans would occur during infancy.

Dimethyl-, diethyl-, di-n-propyl, and other nitrosamines in foods are determined semiquantitatively as follows: (a) initial extraction of the nitrosamines from foods into suitable solvents, (b) isolation of the nitrosamines from other interfering materials by steam distillation and ion exchange cleanup, (c) detection and semiquantitative estimation by TLC, and (d) final identification by GLC analysis of the separated compounds. The detection limit for dimethylnitrosamine in foods was 0.15 ppm and for diethyl- and di-re-propylnitrosamines, 50 ppb. The method has been successfully applied to wheat flour, fish, cheese, and spinach samples.

No abstract

A total diet, representative of a Canadian's dairy food intake was formuIated, grouped by types of food, and prepared as for eating. Analysis of these composites for residues showed eleven organochlorine but no organophosphorus pesticides. Residues were low and would yield an average total daily intake of 24pgI personlday. The level of arsenic was determined on one-quarter of the samples and was found to be consistently below 0.1 ppm.