Experiment 20 The Determination of Iron in Foods by Standard Addition By Elizabeth Sims

Purpose of Experiment signal The main goal of this experiment is to find the weight percent of Iron in food through the method of standard addition Also, this experiment shows that by analyzing a graph of the concentration of the three standards vs. their corresponding absorbance's, the concentration of the unknown can be found through the equation of a line in the form y = mx+b. This is done by solving for the x intercept which gives the concentration of the unknown. signal concentration

Purpose Of Experiment It is also important to note that this experiment has practical use, because it could be used to compare the Iron content in a variety of different foods

Background Information The method behind standard addition is to add a portion of unknown sample which will then be spiked with a known quantity of standard, and the increase in signal observed is attributed to the standard. Hence the standard is subjected to the same environment as the analyte (Iron content in Peas) under investigation. In this experiment, spectrometric analysis was used which measures the intensity of em radiation admitted or absorbed by the analyte

Question In this experiment how is the unknown Iron content calculated? ----By solving for the x intercept of the line created by standard addition