Distribution of di-(2-ethylhexyl) phthalate in leaf cuticular waxes and leaf tissues of plants

Di-(2-ethylhexyl) phthalate (DEHP) as plasticizer is widely used in the modern plastic manufacturing industry, DEHP and its breakdown products have been identified as a global environmental contaminant. Vegetables and crops which are the energy sources of human beings are often exposed to DEHP, which enriched in humans through the food chain, resulting in many diseases. The content distribution of DEHP in leaf cuticular waxes and tissues of 14 plants including vegetables and crops, and in various parts of cells of 4 plants were investigated by gas chromatography–mass spectrometer (GC–MS). The results show the stronger the DEHP uptake ability of the plant the less ratio of DEHP in leaf cuticular wax occupying the total DEHP in the leaves of the plant. DEHP in atmosphere is adsorbed by leaf cuticular wax or stoma, then transferred to inner tissues through cell wall. Interestingly, we found that the leaf cuticular wax and cell wall of plants are possible barriers to uptake of DEHP for the plants possessing lower DEHP uptake ability. Our results will provide some information for further study on the mechanism of DEHP uptake by plants.