1. 1 Student: D.N. Guo Recovery and extraction of heavy metal ions using ionic liquid as green solvent International Journal of Modern Physics B Vol. 20, Nos. 25, 26 & 27 (2006) 4051-4056 MAS AMI KUMANO, TOMOKI YABUTANI and JUNKO MOTONAKA*

2. 2 Contents Introduction 1 Experimental 2 Results and discussions 3 Conclusions 4

3. 3 Introduction  Organic solvents are useful for separation, extraction and synthesis. "Green Chemistry" has been advocated in engineering and science field.  In the concept of Green Chemistry, it is desirable to reduce consumption of conventional organic solvent for reduction of the environmental and human health risks.

4. 4 Introduction  They are molten salts composed of organic cations and various anions. Ionic liquids are in liquid form at room temperature and offer excellent potentials for alternative solvent.  They have unique features that are high ion conductivity, chemical stability, non-volatility and high thermal stability.

5. 5 Introduction  They have already been used in organic synthesis, solvent extraction, chromatography and electrochemistry such as chargeable buttery, fuel cell, capacity, light emission device and wet solar cell.  In this work, extraction of heavy metals in wastewater using ionic liquid as green solvent was examined. The effects of 8-HQ concentration, shaking time and volume ratio on the extraction efficiency were investigated.

6. 6 Experimental Apparatus ICP-AES, thermostat, pH meter, HPLC Materials N,N-Diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis (trifluoromethansulfonyl) imide 8-hydroxyquinoline(8-HQ), nitric acid, phosphoric acid HPLC-grade methanol Potassium dihydrogen phosphate

7. 7 Experimental Sample polypropylene tube centrifuged aqueous phase (add 2mol/l HNO3) ICP-AES ionic liquid phase HPLC

8. 8 Experimental

9. 9 Results and discussions

10. 10 Results and discussions

11. 11 Results and discussions

12. 12 Results and discussions

13. 13 Results and discussions

14. 14 Conclusions  It was possible to obtain high extraction efficiency of heavy metal ions using ionic liquid with 8-HQ as metal chelating agent.  Extraction efficiency depended on the concentration of 8-HQ and its chelating stabilities to analyte.  Under the optimal condition, 1424 μg of heavy metal ions were recovered in the 100 μl of ionic liquid.

15. 15 Thank you for your attention