The Colorimetric Determination of Iron in Biological Material with Reference to its Measurement During Chelation Therapy

Abstract

Iron may be determined in biologic material by a wet-ash method employing chloric and nitric acids and a non-ash method using trichloroacetic acid treatment. Bathophenanthroline or bipyridyl is utilized for color development, performed in a buffered medium with mercaptoacetic acid as reductant. The wet-ash technic is best for estimating total iron in urine, and the non-ash technic for nonhemoglobin-bound urinary iron and iron excretion during chelation therapy. Recovery and precision studies indicate a high degree of reliability. Bilirubin, hemoglobin, and excess phosphates have no significant effect on iron estimation and interference of copper and cobalt may be eliminated. Urinary iron excretion levels for 14 normal healthy children were 32-285 µg./24 hr. (mean, 113.45 ± 76 µg.); for 11 with sickle cell anemia, 115-1270 µg./24 hr. (mean, 685.4 ± 374.3); and for 2 with thalassemia major, 120-690 µg./24 hr. (mean, 363.3± 160.0).