Temporal limitations in the use of potassium dichromate as a blood preservative for the analysis of organohalogenated contaminants including polybrominated diphenyl ethers, dioxins and PCBs

TLDR: The use of Potassium dichromate (K2Cr2O7) has been successfully employed as a preservative for cows' milk and in a World Health Organization study of human milk.

Abstract: Previous studies described the use of potassium dichromate (K2Cr2O7) to successfully preserve whole blood for up to 34 days at room temperature (20–22°C) for analysis of chlorinated dioxins, dibenzofurans and PCBs. Potassium dichromate has been successfully employed as a preservative for cows’ milk and in a World Health Organization study of human milk. The use of two 100 mg tablets in 40 to 100 mL of whole blood in anticoagulant was found to provide almost identical levels of dioxins, dibenzofurans, PCBs and lipids as found in frozen comparison blood at −70°C which is generally regarded as the gold standard for blood preservation. Potassium dichromate was found to be preferable to 20 and 40% ethyl alcohol for this preservation. This finding opens opportunities for preservation under field conditions in developing countries where neither electricity nor dry ice is available. Not having to use dry ice for shipping also allows more flexibility in the choice of commercial carriers for transporting blood to a...