Flame Atomic Absorption Spectroscopic Determination of Iron in Breakfast Cereals

A validated analytical chemistry laboratory experiment for the determination of iron in six brands of breakfast cereals with flame atomic absorption spectroscopy (FAAS) is presented. The cereal sample was dry-ashed in a silica or alumina crucible at high temperature, and consequently dissolved with hydrochloric acid solution. To minimize the matrix effect on the analytical signal, the standard addition method was used in sample preparation prior to the analysis step. Atomization was accomplished with air/acetylene flame, and absorbance measurements were made at the 248.3 nm iron resonance line. Results obtained by forty-one students in a multi-section analytical chemistry course are reported. In addition to providing a milieu to learn the fundamentals of FAAS and the standard addition methodology, this laboratory experiment demonstrates the application of FAAS to analyze food products familiar to students, and therefore makes the learning experience more germane. The validation of the experimental procedure was performed by determining the iron content of a National Institute of Standards and Technology (NIST) Standard Reference Material (SRM) Fortified Breakfast Cereal.