[Fluorine in vegetables and potatoes from the market in Warsaw]

In 65 samples of vegetables: cabbages, carrots, beetroots, onions and potatoes, of whose consumption is the highest in Poland, fluorine content was determined. The samples were prepared according to AOAC method, and fluorine concentration was determined in the filtrate by the potentiometric method using a Fluoride--selective electrode--model 920A of Orion Research Inc. The recovery rate of fluorine was 95 +/- 5%. The average level of soluble fluorine ranged from 3.36 mg/kg of dry weight of cabbage to 5.37 mg/kg of dry weight of onion and from 0.38 mg/kg of fresh weight of cabbage to 1.02 mg/kg of fresh weight of potatoes. In over 50% of the investigated samples fluorine content exceeded 0.56 mg/kg of fresh weight, which is the upper limit value of fluorine content found in the vegetables from the areas ecologically clean.