Atomic Absorbance Spectroscopy Lab Report

Mass Determination of Ca, Fe and Zn in a multivitamin using Atomic Absorbance Spectroscopy (AAS) and X-Ray Fluorescence Spectroscopy (XRF) ABSTRACT: The purpose of this project was to determine the amount of calcium, iron and zinc present in an over the counter multivitamin. This mass was determined using atomic absorption spectroscopy (AAS) and X-ray fluorescence spectroscopy (XRF). For both analytical techniques, the method of standard additions was used to compensate for matrix effects. After result analysis, it was determined that neither analytical instrument was more effective in determining the amount of elements present in the multivitamin over the other. Each had its own elemental downfall. gkjkkkkkkkkkkkkkkk
INTRODUCTION:
Concentrations versus absorbance were used as the axes. The calibration curve for Ca is displayed below in Figure 1.
To calculate the concentration of the unknown, the linear regression line was set to zero, and x was calculated in ppm. This ppm was subjected to a series of mathematical adjustments to account for the multiple dilutions. The calculations can be seen in the attached data and calculations. It was experimentally determined that mass of the Ca was 21.8 mg per tablet, the mass of the Fe was 1367.7 mg per tablet, and the mass of the zinc was 121.4 mg per tablet.
X-Ray Fluorescence Spectroscopy
From the data, tables were constructed for each element. The mass of each element was calculated in mg from the mass percent. These values can be seen in Table 4 for Ca. This data was then converted to a calibration curve as seen in Figure 2.
The equation of the calibration was set to 0, and x was calculated. This value was then multiplied by the total mass of four tablets and divided by 4. This value is the amount of element present in each tablet. It was experimentally determined that mass of the Ca was 1862.3 mg per tablet, the mass of the Fe was 26.2 mg per tablet, and the mass of the zinc was 380.1 mg per