Total reflection X-ray fluorescence analysis of trace elements in Bulgarian bottled mineral waters of low and high mineral content

The trace elements S, Cl, K, Ca, Mn, Fe, Ni, Cu, Zn, As, Br, Rb and Ba in Bulgarian bottled mineral waters of low and high total dissolved solids (TDS) content were determined by total reflection X-ray fluorescence (TXRF) analysis using gallium as internal standard. The water samples were analysed after simple preparation consisting in three-fold sequential pipetting/drying of 5 μL portions of the water sample mixed with the internal standard on the quartz holders. The precision of the obtained results is characterised by an RSD of 5–16%. The lower limits of detection (LLDs) in waters of TDS content of 160–420 mg L−1 were in the low µg L−1 range, whereas those in the water with TDS content of 2900 mg L−1 were higher by a factor of 5–15. There is a good agreement between the results for the trace element content obtained by TXRF and inductively coupled plasma optical emission spectrometry (ICP-OES) for mineral waters with TDS content in the range from 160 to 2900 mg L−1.