Class: BE210
Group: W1
Members:
FACILITATOR KELSEY CHRISTIAN
TIME & TASK KEEPER ELIZABETH IRISH
SCRIBE DANIEL LEUNG
PRESENTER ANDREW CHEN
Date: May, 2002
Abstract:
Using the Perkin Elmer AAnalyst 100 Atomic Absorption Spectrometer
(AAS), the calcium content of Tums was discovered to be over 100% of the
listed value, just as was hypothesized. For two tablets, the amount of
calcium present was 439 ± 12 mg. The difference between the value
stated on the label and the experimental value is +10%. The amount of variance
between each sample was 0.2%, whereas the standard error was 2.7%.
The measured calcium concentrations for the Tums samples were obtained
from a standard solution curve for calcium that related absorbance to concentration.
To ensure a linear relationship, the curve was set within the linear range
of the AAS (1-5 ppm). The R2 value of the standard solution curve was 0.9999,
ensuring the validity of the values. To compensate for the possible effect
of viscosity on the accuracy of the absorbance readings, the Method of
Additions was employed. With an R2 value of 0.9995 on the curve established
with the Method of Additions, it was observed that viscosity does not significantly
affect the absorbance readings by the AAS.