Determination of essential elements in beverages, herbal infusions and dietary supplements using a new...

A simple method based on FAAS was developed for the sequential multi-element determination of Cu, Zn, Mn, Mg and Si in beverages and food supplements with successful results. The main absorption lines for Cu, Zn and Si and secondary lines for Mn and Mg were selected to carry out the measurements. The sample introduction was performed using a flow injection system. Using the choice of the absorption line wings, the upper limit of the linear range increased up to 110mgL^-1 for Mg, 200mgL^-1 for Si and 13mgL^-1 for Zn. The determination of the five elements was carried out, in triplicate, without the need of additional sample dilutions and/or re-measurements, using less than 3.5mL of sample to perform the complete analysis. The LODs were 0.008mgL^-1 for Cu, 0.017mgL^-1 for Zn, 0.011mgL^-1 for Mn, 0.16mgL^-1 for Si and 0.11mgL^-1 for Mg.