Determination of Iron and Potassium in Graphene Oxide by Flame Atomic Absorption Spectrometry

The graphene oxide sample (0.10 g) was placed into a platinum crucible, and a pre-treatment method of drying at 120℃ for 4 h, ashing at 220℃ for 4 h, burning at 1 000℃ for 2 h, and dissolving residual oxides with mixed acid was carried out. Under the conditions of Fe 248.3 nm and K 766.5 nm, slit widths of 0.2 nm (Fe) and 0.5 nm (K), flow rate of acetylene as flame gas at 1.0 L·min^-1, and flow rate of air as auxiliary gas at 4.0 L·min^-1, iron and potassium in the above sample were determined by flame atomic absorption spectrometry. As shown by the results, linear ranges of the standard curves of iron and potassium were both 0.020%-0.500%, with the same detection limits (3s) of 0.001%. RSDs (n=12) of the determined values of iron and potassium in graphene oxide samples were ranged from 0.70% to 7.6%. Test for recovery was made by standard addition method, giving results in the range of 94.0%-106%. The proposed method was applied to analysis of actual samples, and the determined values were basically consistent with those obtained by inductively coupled plasma atomic emission spectrometry in literature.