[Determination of nitrate in raw spinach and commercially-prepared baby food]

During the years 1972--1975, the author performed nitrate determinations, using the xylenol method according to E. Bohm, to verify if the standard or maximum permissible values established by the Ministry for Health of the GDR in 1972-1973 for spinach and spinach preserves for babies had been respected. The relative standard deviation of the method is +/- 5%. The values found in spinach samples of the same harvest and from the same area varied considerably (up to +/- 40% of the mean). Taken altogether, the nitrate content, especially in autumn spinach, exceeded by far the maximum permissible values for baby food as well as for general consumption in spite of contractual agreement with the farmers on the use of nitrogenous fertilizers. It is recommended to study systematically all the factors of nitrate accumulation in order to secure safe spinach products.