Formaldehydeinterferencewith Fluorescencedeterminationof Morphinein Urine " Disappearing " Lipoprotein-x

toglobin was determined by the method of Ratcliff and Hardwicke (6). Serum haptoglobin concentration in the normal controls was 1439 ± 405 mg/liter; in the cases of pure iron deficiency it was 798 ± 323 mg/liter. In the cord sera the concentration of haptoglobin was 195 ± 112 mg/liter. The patients’ values for serum haptoglobin were clearly (P <0.001) lower than those of normal controls. It is difficult to find cases of pure iron-deficiency anemia in our population. Usually other nutritional deficiencies are associated. Thus the number of cases we studied is small. Still, a highly significant decrease in serum haptoglobin was seen in these patients. This decrease may be a sign of mild hemolysis in these cases, equivalent to 640 mg of hemoglobin per liter; that is to say, rather less than 1% of the total amount of hemoglobin in the blood.