[Content estimation of nitrates and nitrites in vegetables from the province of Lodz]. / Ocena zawartosci azotanów i azotynów w warzywach pochodzacych z terenu wojew-odztwa L-odzkiego.

The contents of nitrates and nitrites in selected vegetables reaped in summer and autumn in 1993 were investigated. The samples of vegetables were collected directly from the producers from area of Lódz and from outside of the city. Nitrates were reduced on a cadmium column to nitrites, where-upon they were determined colorimetrically using sulfanilic acid and N-1-Naphthylethylenediamine. It has been found that the contents of nitrates in tested vegetables are mostly higher than the allowable values published in the Ordinance of Minister of Health and Social Welfare from 8th of October 1993. The average contents of nitrates and nitrites in most of tested vegetables were higher in the vegetables from the outskirts of the city than in ones from outside of the city in the province.

[Studies on the contents of nitrates and nitrites in selected fresh and heat processed vegetables]. / Badania zawartosci azotanów i azotynów w wybranych warzywach surowych oraz poddanych obróbce termicznej.

The levels of nitrates and nitrites were determined in fresh vegetables and the same products subjected to culinary processing such as boiling. Nitrates were reduced on a cadmium column to nitrites, where upon they were determined colorimetrically using sulfanilic acid and N-1-naphthyl-ethylenediamine. Thermal processing of these vegetables reduced the level of nitrates by about 50% and the nitrites loss reached even 100%.