Direct determination of several elements in MIBK extract by high-power nitrogen-oxygen mixed gas microwave-induced plasma optical emission spectrometry

A nitrogen-oxygen mixed gas microwave-induced plasma with an Okamoto cavity was employed as an atomization and excitation source for emission spectrometric analysis of organic solvent samples. Nitrogen-oxygen mixed gas produces very a stable microwave-induced plasma that is highly robust to the loading of 4-methyl-2-pentanone (MIBK), possibly because the organic solvent is completely combusted in the oxygen-containing plasma. After extracting test solutions containing Al, Co, Cr(III), Cu, Fe(III), Mo(VI), Ni, Pb with MIBK, both the aqueous phase and the organic phase were aspirated into the microwave-induced plasma, yielding linear calibration curves for both the species in the aqueous phase (Al, Co, Cr, Ni, and Pb) and those in the organic phase (Fe and Mo). These results indicate that Fe and Mo can be extracted with MIBK, which is explained by the partition coefficients of these elements in MIBK.