Dipropylnitrosamine Levels in a Tomato Field a t concentrations of 0.05, 0.10, and 0.25 ppm and the samples were extracted and analyzed as described above, the mean percent recovery at each level was 93.5,98.6, and 89.2, respectively. Typical control values for both 0naphthoxyacetic acid and 0-naphthol were
