The Use of Atomic Absorption Spectroscopy in Hemoglobinometry: I. The Determination of Iron in Hemoglobin

Abstract

Atomic absorption is finding wide acceptance as a convenient method of metal analysis in biologic materials. The specificity and accuracy of the method, and the convenience of direct analysis of samples, requiring no preparation other than simple dilution, make the use of this technic highly desirable for iron analysis of hemoglobin. In order to take full advantage of the potentials of the technic, we were interested in investigating whether the analysis of aqueous hemoglobin solutions by direct aspiration into the flame gave accurate values for iron. Interfering effects might be observed from the incorporation of the iron in the hemoglobin molecule itself, or from the presence of other components of the sample matrixderiving from whole blood constituents. We were able to show that very accurate quantitative iron determinations can be obtained when simple aqueous dilutions of toluene hemolysates of hemolyzed washed cells or of hemolyzed whole blood were analyzed. No effect on the iron values was seen from the concomitant constituents of hemolysates or of whole blood when dilutions of 100-fold or greater were used. Instrumentation and technics. A PerkinElmer atomic absorption spectrophotometer model 303 (Perkin-EImer Corporation, Norwalk, Connecticut) was used. The standard instrument settings were: neon-filled iron hollow cathode tube, operating current, 30 ma.; analytical resonance line, 24S3 A; monochromator slit, 3; flame, acetylene-air, stoichiometric. The baffle system of the burner was modified as described previously. The aspirator capillary was replaced by a 10-in. length of polyethylene tubing of 0.030 in. i.d. (Clay-Adams Intramedic Pol}'ethylene tubing, PE 60). A wide-slot