Mechanism of modification by palladium in graphite furnace atomic absorption spectrometry

摘要: Abstract The effects of palladium and mixtures containing on the absorbance characteristics lead, thallium, cadmium, selenium, manganese cobalt are described. These data, together with results scanning electron microscopy showing distribution graphite surface, indicate that has a physical mechanism analyte modification. During furnace heating, dissolves in molten may combine it chemically. However, rate limiting step leading to atomization appears be diffusion from palladium. addition magnesium, molybdenum or powdered carbon increases speed by causing form smaller droplets, hence produces sharper peaks. Palladium becomes less effective as temperature increases, because is higher. This accounts for having only small stabilizing effect volatile elements such cobalt. ascorbic acid no significant its modifying properties dilute nitric matrix. Results kinetic studies gold consistent out rate-limiting atomization.