[Values of nitrates and nitrites in selected vegetables given to hospitalized children].

In the study the levels of nitrates and nitrites were determined in certain vegetables used in preparation of meals for hospitalized children. The material studied comprised vegetables taken in three seasons of the year: autumn, winter, spring. Nitrates and nitrites were determined by the colorimetric method with Griess reagent after previous reduction of nitrates to nitrites with metallic cadmium. The content of nitrates, over 1 g NaNO3/kg, was found in celery, beet-roots, lettuce, green leaves of parsley and cabbage, even up to 10 g NaNO3/kg, in winter and spring in onions, leek and potatoes, and in autumn and spring in carrots. In 85% of the determinations the nitrite level was below 5 mg NaNO2/kg. An important source of nitrates in the food rations of the hospitalized children throughout the whole investigation period was lettuce, in autumn potatoes, in winter carrots and celery, and in winter and spring beet-roots.