Deborah K. Bradshaw

Using internal standards is a common technique to correct for variations in sample matrices and the effect this has on analyte intensities. There are several basic criteria to be considered when using internal standards: selection of appropriate internal standards, the concentration added to the solutions analyzed, setting up in the correct view (axial vs. radial), how to introduce the internal standard to the solutions to be analyzed, and evaluating the resulting data. Each of these topics are considered and suggestions presented.

Contrary to popular belief, neither good “spike” recoveries nor the use of the method of standard additions (MSA) will guarantee accurate results in ICP-OES.