Trace element determinations in foods and biological samples using inductively coupled plasma atomic emission spectrometry and flame atomic absorption spectrometry

Elemental food composition data are important to both consumers and health professionals, and recent food labeling legislation has highlighted this need. Rugged, accurate, and precise analytical methods are needed for elemental analyses, and atomic spectroscopic techniques are the best choice because of their widespread availability and ease of use. Flame atomic absorption spectrometry (AAS) and inductively coupled plasma atomic emission spectrometry (ICP-AES) methods were compared, focusing on the detection capability, precision, and accuracy obtainable with each technique. Ca, Cu, Cr, Fe, Mg, Mn, and Zn were determined by AAS, and Ca, Co, Cu, Cr, Fe, Mg, Mn, Ni, P, V, and Zn were determined simultaneously using ICP-AES. Detection limits for both techniques were typically in the part per billion range and in all cases were sufficient for the accurate quantitation of elements of nutritional interest. Precisions obtainable with both techniques were similar, and both provided accurate elemental food composition data based on the analysis of four certified reference materials and a variety of foods using either a wet ash or dry ash sample preparation procedure.