Direct determination of lead in plastic toys by solid sampling high resolution-continuum source graphite furnace atomic absorption spectrometry

摘要

In this study, lead concentrations in various plastic toys were determined directly by solid sampling high resolution continuum source graphite furnace atomic absorption spectrometry. The toys were cut into small pieces and introduced into the graphite furnace between 0.05 and 0.7 mg without any further treatment. Lead was determined at 217.005 nm using a Pd + Mg modifier. The samples were pyrolyzed at 1000 ℃ and atomized at 2200 ℃ with or without gas flow at the atomization stage depending on the concentration of the analyte. The lead concentration in a certified reference plastic material (ERM-EC680K) was determined in the uncertainty limits of the certified value. The limits of detection in gas-stop and gas-flow modes for 0.7 mg of sample were 0.037 and 0.93 mg kg~(-1), respectively. The concentrations of lead in plastic toys of different colours were found to be in the range of 0.060-9.12 mg kg~(-1).