Effect of heat on the conversion of di‐2‐ethylhexyl phthalate to mono‐2‐ ethylhexyl phthalate in human plasma

Abstract
Plasma di-2-ethylhexyl phthalate (DEHP), which accumulates during blood storage in plastic bags, gives rise to plasma mono-2-ethylhexyl phthalate (MEHP). This phenomenon occurs not only during blood storage, but also in plasma samples awaiting analysis, which are no longer stored in plastic bags. Heating plasma samples at 60.degree. C for 25-30 min in a water bath halted conversion of DEHP to MEHP during subsequent room temperature storage for at least 100 h. This result was consistent with the view that MEHP accumulation in plasma was due to enzymatic hydrolysis of DEHP by esterase(s) which could be heat-inactivated.