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 also in plasma samples awaiting analysis, which are no longer stored in plastic bags. Heating plasma samples at 60 C for 25 to 30 minutes in a water bath effectively halts conversion of DEHP to MEHP during subsequent room temperature storage for at least 100 hours. This result is consistent with the view that MEHP accumulation in plasma is due to enzymatic hydrolysis of DEHP by esterase (s) which can be heat-inactivated.
Subject(s)
Diethylhexyl Phthalate/metabolism , Hot Temperature , Phthalic Acids/metabolism , Blood Preservation , Diethylhexyl Phthalate/analogs & derivatives , Humans , Hydrolysis , Time FactorsABSTRACT
Plasma DEHP concentrations were measured weekly in whole blood and red cell concentrates (RCC) during 21 days of storage in standard CPD within PL-130 blood bags. In addition, DEHP and MEHP accumulation patterns were investigated in blood stored for 42 days in modified CPD with adenine within PL-146 and BB-69 storage containers. Total per-unit plasma DEHP of RCC units was 49 to 71 per cent of the total in plasma of whole blood units (PL-130). From 28 to 42 days, mean DEHP levels were 12 to 19 per cent higher in whole blood stored in PL-146 than in BB-69. Although MEHP was not found in any blood bag plastic, MEHP accumulated in plasma during whole blood storage. MEHP concentrations were 2.8 to 3.8 times higher in plasma stored in BB-69 than in PL-146. It is postulated that MEHP arises from hydrolysis of DEHP by plasma lipase, even in frozen plasma sample, and that the rate of this reaction is influenced by blood bag plastic surface characteristics.
