Top Tips for Analyzing Elemental Nutrients and Contaminants in Food With AAS

Atomic Absorption Spectroscopy (AAS) is an inexpensive and mature elemental analysis technique used in thousands of laboratories. Food laboratories use AAS to analyze a diverse range of foods for nutritional and/or safety purposes.

While AAS has been around for decades, modern design enhancements have automated key sample preparation and method development processes. For example, in food labs, up to eight or more elements may be determined in each sample. Analyzes can include Na, K, Ca, Mg, Cu, Ni, Fe, Zn etc. for nutritional information and/or Pb, As, Se, Cd for food safety purposes. Measuring this large number of elements can be slow, with each being measured one at a time. Agilent AA instruments can measure multiple elements each time a solution is aspirated. This ability saves time and reduces both errors and having to remeasure samples over and over to get the results you need. The instrument behaves more like an ICP-OES or ICP-MS with their multi-element measurement capabilities.

Standard and sample preparation is also a part of food sample analysis. In a typical day, an analyst using an AAS maybe required to prepare up to 10 calibration standards, dilute samples and perhaps add an ionization buffer to every sample. These steps can introduce contamination and error into the analysis. Flame AA analysis steps such as instrument calibration and sample preparation can be automated to avoid these potential sources of error. This automation has the added benefit of improving the analysis workflow and reducing costs.

Achieving high sensitivity and accuracy is necessary to detect low levels of food safety elements. Food samples are complex. They contain a wide array of elements in highly variable concentrations─making it difficult to get the correct result. Challenging matrices, like the presence of high salts, can be overcome using Zeeman background correction in graphite furnace atomic absorption (GFAA). Zeeman background correction offers the background removal performance required for sensitive and accurate measurement of low-level elements. It can often be challenging to get the method right for GFAA, but there are software tools that can automate this process.

Speaker Information: