Diffusion of CO₂ and O₂ Through the Walls of Plastic Syringes

Abstract

The diffusion of O 2 and CO 2 through the walls of two types of plastic syringes was measured. When the syringes were filled with 16% O 2 , 5% CO 2 , and the balance N 2 , the average outward diffusion of CO 2 was 0.076% per hour and the average inward diffusion of O 2 was 0.06% per hour in room air at room temperature. When the syringes were surrounded by room air cooled in ice the average loss of CO 2 was 0.137% per hour and the average increase in O 2 content 0.10% per hour. From the measurements we conclude that diffusion of gases through the walls of disposable syringes cannot be responsible for the low [Formula: see text] values of "normal" arterial blood reported by clinical laboratories.