Manometric Determination of Hemoglobin by the Oxygen Capacity Method

Since Van Slyke (1) originally described a gasometric method for the determination of hemogIobin by analysis of the oxygen-combining power of blood, it has been the practice to saturate the blood with air at atmospheric pressure in a separate vessel and to transfer a sample of the aerated blood to the gas analyzing apparatus. A method is described here which requires less time, material, and apparatus, because both saturation with air and the subsequent oxygen analysis are performed in the chamber of the Van Slyke-Neil1 apparatus (2). Lundsgaard and Miiller (3) described a technique of this kind for use with the Van Slyke constant pressure apparatus, but it cannot be used with the Van Slyke-Neil1 chamber. Saturation by shaking the undiluted blood in the chamber of the latter apparatus filled with air has been found to be impractical; the viscosity leads to emulsion formation with the mercury and foam formation. If the blood is Iaked and diluted with water, the affinity of hemoglobin for oxygen is so much decreased that sat,uration with air fails to make the hemoglobin t,ake up its maximum volume of oxygen. If the blood is diluted with isotonic sodium chloride solution, however, the hemoglobin maintains its normal affinity for oxygen, and can be completely oxygenated by aeration at ordinary pressures. Furthermore, since no frothing or formation of minute air bubbles within the liquid occurs, the material can be agitated without the use of octyl alcohol, and hemolysis is avoided. Blood may be aerated as well as analyzed in the chamber of the Van Slyke-Neil1 apparatus, in samples of 1.0 to 0.2 cc. The correction for physically dissolved oxygen is large, but it can be so accurately