Phosphate contamination of commercial heparin.

Heparin is widely used as an anticoagulant in biochemical laboratories. Hawk, Oser, and Summerson (1947) state that heparin is an excellent anticoagulant, as it does not alter the distribution of diffusible substances between cells and plasma. Jorpes (1946) states that heparin neither influences the volume of the blood corpuscles nor interferes with the chemical analysis. In the course of routine estimations of plasma inorganic phosphorus (P), it was noted that the heparin used was heavily contaminated with phosphate and was responsible for erroneously high values. We have not been able to find any report suggesting that heparinized blood is not suitable for the estimation of phosphate.