Class: BE-210
Group: W2
Members: Marc Chodock, Benjamin Fleischer, Ava Segal, Kimberly Kirby
Date: April 30, 1998
Full Text

Abstract:
The iron fraction in hemoglobin (Hb) was calculated using atomic absorption spectrophotometry (AAS) to be 0.32% (p = 0.04) by mass. The number of Fe atoms/molecule Hb was calculated from the literature molecular weight of Hb (mw = 64.5 kd ) to be 3.65. The literature values are 0.34% and 4.00 respectively. Assuming the literature value of 4.00 atoms of iron per molecule Hb, the MHb = 70.5 kd compared to the literature value of MHb = 64.5 kd. The 95% confidence intervals allow this deviance.

Hemoglobin was found to affect the absorbance curve for iron upon nebulization (p = 0.16). The percent of iron lost per ppm of hemoglobin was calculated using linear regression. The function was used to correct the [Fe] calculated in hemoglobin and yield a new mass fraction of 0.32%. It was hypothesized that the decrease in concentration at higher values of Hb was due to a decrease in flow rate and subsequent decrease in the effective [Hb] measured.

Alternative methods of removing the hemoglobin from solution were explored. Hemoglobin solutions were made by adding dilute tricholoroacetic acid (TCA) in one trial and nitric acid in another. In the TCA solutions ranging from 2.5 to 10% of 6 M, an average of 85.10% of the iron was removed as precipitate. The nitric acid, ranging in concentration from 2.5 to 10% of 6 M, caused 77.83% of the iron was removed as precipitate. The benefit of acid treatment is therefore in the precipitation of protein for removal rather than in releasing iron from the heme group. As an application, the experimental mass fraction was used to calculate the hemoglobin content of coagulated horse serum to be 1628 ppm.