Atomic Spectroscopy in Food Analysis

Abstract

AbstractSince food is the primary source of essential elements for humans, the accurate and precise analysis of food materials is critical. The methods best suited to meet this task are atomic spectroscopic methods such as atomic absorption, atomic emission, and elemental mass spectrometry (MS). Methods commonly used in the generation of food composition data include flame atomic absorption spectrometry (FAAS), graphite furnace atomic absorption spectrometry (GFAAS), inductively coupled plasma atomic emission spectrometry (ICP/AES), and more recently, inductively coupled plasma mass spectrometry (ICP/MS). FAAS and ICP/AES offer similar detection limits (DLs) (ng mL−1levels), whereas, GFAAS and ICP/MS can provide sub‐ng mL−1detection capability. The choice of a method often depends on detection capability, but ease of use, speed of analysis, and cost must be considered. ICP/AES and ICP/MS offer the advantage of providing simultaneous multielement measurements, making them well suited for the analysis of large numbers of elements in food samples. If one or a few elements are to be determined, less expensive atomic absorption spectrometry (AAS) methods might be more suitable. The most critical stage in the development of analytical methods is sample preparation. Samples can be prepared using numerous procedures, but the most useful for a wide range of analytes and sample matrices are based on dry ashing or wet ashing of the sample. In addition to total element determinations, speciation measurements are important to determine the exact form of the element that is present in the sample. Since the bioavailability of an element is dependent on its chemical form (speciation), the development of reliable methods for identification and quantification of trace element species is critical. The coupling of chromatographic separation and atomic spectroscopic detection has proven useful for elemental speciation measurements.