N. Kallithrakas-Kontos, "TXRF heavy metal analysis after immobilization as PAN complexes," X-ray Spectrom., vol. 33, no. 1, pp. 12-15, Oct. 2003. doi: 10.1002/xrs.661
https://doi.org/10.1002/xrs.661
1-(-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.