Interferences in the Determination of Metallic Elements in Human Hair

Abstract

Hair, a metabolic end product, has been used to indicate health status. Our purposes in this study were: (1) to evaluate the hair digest matrix as a source of interferences in the determination of metals using atomic absorption spectrophotometry, and (2) to develop a technique whereby meaningful interlaboratory comparison of analytical data can be made. We have demonstrated that for hair analysis, Interferences due to broad-band nonspecific molecular absorption, chemical ionization, flame emmission, flame scatter, light scatter, and matrix matching can be avoided using ordinary methods and commercially available equipment. We have also presented a technique for the preparation of a standard reference hair sample. This standard reference hair was then used to demonstrate that concentrations of copper, zinc, lead, and cadmium in a nitric acid hair digest matrix can be measured with precision and accuracy.