TXRF heavy metal analysis after immobilization as PAN complexesTXRF heavy metal analysis after immobilization as PAN complexes Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2015-10-092003en1-(-2-Pyridylazo)-2-naphthol (PAN) forms stable complexes with many metals of environmental interest. A few micrograms of PAN were immobilized in a Nafion membrane, the membrane was put on quartz reflectors and the reflectors were immersed in standard aqueous solutions containing nickel, copper, manganese and vanadium salts at very low concentrations (µg l−1 level). The reflectors were left in the solutions for many hours at constant temperature. When the equilibration stage was finished, they were cleaned with ultra-pure water and left to dry. Analysis of the samples was performed by total reflection x-ray fluorescence (TXRF) spectrometry. A few µg l−1 of the above metals were determined. The effects of equilibration time and temperature on the measured x-ray yields were examined. Δημοσίευση σε επιστημονικό περιοδικό http://creativecommons.org/licenses/by/4.0/X-Ray Spectrometry33112-15 Kallithrakas-Kontos Nikolaos Καλλιθρακας-Κοντος Νικολαος John Wiley and Sons PAN Membrane Total reflection x-ray fluorescence