STUDY ON MICROWAVE-ASSISTED DIGESTION OF BIODIESEL FOR DETERMINATION OF TRACE ELEMENTS BY ICP-MS

Abstract

Abstract: A microwave-assisted digestion using diluted nitric acid and hydrogen peroxide as auxiliary agent was explored to determine trace elements in biodiesel by inductively coupled plasma mass spectrometry (ICP-MS). The effect of nitric acid concentration and volume of hydrogen peroxide on biodiesel digestion was investigated, using residual carbon content and residual acidity in final solutions as evaluation index. Results showed that 0.6 g of biodiesel was almost completely digested under the optimal conditions: 6 mL nitric acid (6 mol/L) and 2.5 mL hydrogen peroxide. The residual carbon content and the residual acidity in digests were lower than 5.3% and 6.4%, respectively. After sample digested, Ba, Cr, Cu, Mn, Mo, Ni, Pb, Sr, V and Zn were determined by ICP-MS and the recovery rate was in the range of 94.2% to 107.4%. All RSDs were less than 4.33%.

Key words: ICP-MS, microwave-assisted digestion, diluted nitric acid, biodiesel, Trace elements determination

References

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