Nitrate and nitrite contamination of vegetables in the Slovenian market

Overview of the quality of domestic and imported vegetables in Slovene market was investigated in terms of nitrate and nitrite contamination. In total, 145 samples (rocket, lamb's lettuce, silverbeet, spinach, lettuce, cabbage, radicchio, string beans, carrots, cucumber, potato, cauliflower, pepper and tomato) were bought in supermarkets and market places in Ljubljana in 2017. Values over 1000 mg NO₃^- kg^-1 were found in 30% of randomly selected samples. The highest nitrates (4000-7600 mg kg^-1) were determined in rocket, lamb's lettuce, silverbeet, and spinach. They were bought in supermarkets declared as imported samples. Regarding EU regulatory limits, available for rocket, lettuce, and spinach, 17% of the samples exceeded the threshold values. Furthermore, some of them were designated as ecological product (ECO). There are no maximum limits for lamb's lettuce; however, all samples from supermarkets, declared as imported samples, contained very high values of nitrates (>3500 mg NO₃^- kg^-1).