Abstract
Contamination of fruit and vegetables such as grape, cabbage, turnip and cucumber by the detergent solution of sodium dodecylbenzene sulfonate (SUBS) have been investigated by means of the radiotracer method using SUBS labeled with radioisotope 35S. The measurement of contamination was chiefly made for cabbage under varying conditions of the difference in the part and in water content of cabbage leaf, concentration of the detergent solution, dipping time and temperature, and rinsing time. The effect of sodium sulfate as a builder was also studied. Under the usual condition of dipping in 0.1% detergent solution for five min at 1618°C, followed by rinsing twice with 100 cc of water for 20 sec, the contaminations observed were 0.29 γ/cm2 for the surface and 1.8 γ/cm along the cracks and damages of cabbage leaf. Air dried cabbage leaf suffered from stronger contamination than the fresh one. The contamination of grape was about the same but those of turnip and cucumber were three or four times as much as that of cabbage when compared in the unit of contamination per area, but the results were just opposite when the usual unit of contamination per 100 g of the sample was used. We considered the latter expression to be unreasonable.
