Different types of Brassica Campestris plants were grown in soil contaminated with di-n-butyl phthalate (DBP). The researchers used GC/MS to study how DBP accumulated in the plants and soil. They found that the amount of DBP in the leaves and roots varied between different Brassica Campestris genotypes. Some genotypes had higher DBP levels in their leaves and roots, while others had lower levels. The size of the leaves also affected the amount of DBP present. Overall, the distribution of DBP in the plants and soil differed significantly between the genotypes, with some having lower DBP levels in both plants and soil, while others had higher levels.