Extraction of bioactive compounds with ionic liquid aqueous solutions

Transcription

1 universidade de aveiro dqua departamento de química Extraction of bioactive compounds with ionic liquid aqueous solutions Helena Passos Orientadores Prof. Dr. João Coutinho Dr.ª Mara Freire Dissertação/Projeto 5ºAno Mestrado Integrado em Engenharia Química 20 de Julho de 2012

2 Summary 1. Introduction 1.1. Ionic liquids (ILs) 1.2. Aqueous two phase systems (ATPS) 2. Objectives and scopes 3. Experimental procedure 4.1. IL + H 2 O + C 6 H 5 K 3 O 7 ternary systems 4.2. Self-aggregation in IL-based ATPS 4.3. Extraction of bisphenol A (BPA) 5. Conclusions 6. Future work 2

3 1. Introduction 1.1. Ionic liquids (ILs) ILs exhibit unique properties are composed of R 1 large organic cations + Imidazolium R 2 R 1 + R 2 R 3 R 4 Ammonium + Pyridinium R organic or inorganic anions Chloride C O O P O O Dimethylphosphate C Dicyanamide negligible vapour pressure and flammability; high thermal and chemical stability; high solvation ability for several compounds; improved selectivity and easy recycling; tunable properties. Designer solvents Volatile organic compounds substitutes 3

4 1. Introduction 1.2. Aqueous two phase systems (ATPS) Liquid-Liquid Extraction ATPS IL-based ATPS Additional advantages low viscosity; quick phase separation; high and tailored extraction efficiency. two aqueous-rich phases polymer salt salt polymer polymer salt ATPS composed of IL + Salt + H 2 O. 4

5 [IL] / wt % 2. Objectives and scopes To find more benign ATPS by substitution of the high charge density salts usually employed; [C 6 H 5 K 3 O 7 ] / wt % To study the ability of novel ATPS for alkaloids extraction; To study the effect of the ILs self-aggregation and subsequent impact on the partition of different biomolecules; To demonstrated the potential of IL-based ATPS for the extraction of Bisphenol A (BPA). 5

6 3. Experimental procedure Determination of phase diagrams Extraction of bioactive compounds Cloud point titration method 1. ATPS preparation: IL + Salt + Biomolecules 2. Phases separation 3. UV-spectroscopy quantification 4. Determination of: A IL-rich phase Salt-rich phase Partition Coefficient K X X X IL Salt B Cloud point titration method. ATPS composed of IL + Salt + H 2 O. EE Extraction Efficiency X IL mx % 100% IL Salt m m X X 6

7 4.1. IL + H 2 O + C 6 H 5 K 3 O 7 ternary systems IL-based ATPS are commonly composed by inorganic salts environmental concern replaced by biodegradable and biocompatible organic salts 7

8 [IL] (mol kg -1 ) 4.1. IL + H 2 O + C 6 H 5 K 3 O 7 ternary systems ATPS composed of IL + Potassium citrate + H 2 O Cation core effect [C 4 mim]cl - [C 4 mpy]cl + [C 4 mpyr]cl [C 4 mpip]cl [C 6 H 5 K 3 O 7 ] (mol kg -1 ) [ 4444 ]Cl [P 4444 ]Cl [P 4444 ] + > [ 4444 ] + >> [C 4 mpy] + [C 4 mpip] + > [C 4 mpyr ] + > [C 4 mim] + 8

9 [IL] (mol kg -1 ) 4.1. IL + H 2 O + C 6 H 5 K 3 O 7 ternary systems ATPS composed of IL + Potassium citrate + H 2 O 2. Anion effect [C 4 mim][ch 3 CO 2 ] [C 4 mim][po 4 (CH 3 ) 2 ] 10.0 [C 4 mim][ch 3 SO 3 ] 8.0 [C 4 mim]cl [C 4 mim]br 6.0 [C 4 mim][cf 3 CO 2 ] [C 4 mim][(c) 2 ] 2.0 [C 4 mim][sc] - [C 4 mim][cf 3 SO 3 ] [C 6 H 5 K 3 O 7 ] (mol kg -1 ) + [C 4 mim] + cation hydrogen bond basicity [CH 3 CO 2 ] - < [PO 4 (CH 3 ) 2 ] - < [CH 3 SO 3 ] - < << Br - < [CF 3 CO 2 ] - << [(C) 2 ] - < [SC] - < [CF 3 SO 3 ] - 9

10 [IL] (mol kg -1 ) 4.1. ILs + H 2 O + C 6 H 5 K 3 O 7 ternary systems ATPS composed of IL + Potassium citrate + H 2 O 3. Cation alkyl side chain length effect n hydrophobicity solubility [C 4 mim]cl ability for ATPS formation [C 6 mim]cl [C 7 mim]cl [C 8 mim]cl [C 10 mim]cl + R 1 [C n mim]cl [C 6 H 5 K 3 O 7 ] (mol kg -1 ) [C 4 mim] - < [C 6 mim] - [C 7 mim] - [C 8 mim] - [C 10 mim] - 10

11 [IL] (wt %) 4.1. ILs + H 2 O + C 6 H 5 K 3 O 7 ternary systems ATPS composed of IL + Potassium citrate + H 2 O ph effect ph 9 ph 7 [C 4 mim]cl ph 9 ph 7 [C 10 mim]cl [Salt] (mol kg -1 ) + ph effect is negligible 11

12 4.2. Self-aggregation in IL-based ATPS vii viii [C n mim] + are structurally similar to ionic surfactants + + Hydrophilic head x xi + + xii Hydrophobic chain [C 10 mim] - molecular structure. xiii ILs micelle formation in aqueous solution [1] xiv xv [1] C. Jungnickel et al., Colloids and Surfaces A: Physicochem. Eng. Aspects 316 (2008)

13 4.2. Self-aggregation in IL-based ATPS Micelle-mediated extraction can be used to increase or decrease the extraction efficiencies of a given molecule. Extraction of vanillin using ionic-liquid-based aqueous two-phase systems High-performance extraction of alkaloids using aqueous two-phase systems with ionic liquids [2] M.G. Freire et al., Green Chem. 12 (2010) [3] A.F.M. Cláudio et al., Separation and Purification Technology 75 (2010)

14 4.2. Self-aggregation in IL-based ATPS Imidazolium-based IL + C 6 H 5 K 3 O 7 /C 6 H 8 O 7 + alkaloids 14 K Alk ph 7 Alkaloids are predominantly in a non-charged form Caffeine Theophylline Caffeine Theophylline Theobromine n 7 Maximum IL ability of for extraction the micelles [Cformation 6 mim]cl K Alk Theobromine 14

15 Concentration (wt %) 4.2. Self-aggregation in IL-based ATPS Imidazolium-based IL + C 6 H 5 K 3 O 7 + alkaloids Theophylline ph 9 - Theophylline is predominantly in a negative charged form ph 15

16 Self-aggregation in IL-based ATPS Imidazolium-based IL + C 6 H 5 K 3 O 7 + alkaloids Theophylline K Alk T - T - T - T Cl T T - Cl + T - - T - Cl - T - T - T T - T T - T - T- T - T - T T - - Cl T T - T - 0 ph 7 ph 9 K Alk n for charged n 8 interaction molecule micelles between formation > K Alk opposite neutral Kcharges Alk molecule 16

17 Concentration (wt %) 4.2. Self-aggregation in IL-based ATPS Imidazolium-based IL + C 6 H 5 K 3 O 7 + alkaloids icotine ph 7 icotine is predominantly in a positive charged form ph 9 icotine is preferentially in a neutral form (58 wt % of neutral molecule and 42 wt % of positively charged molecule) H ph 17

18 4.2. Self-aggregation in IL-based ATPS Imidazolium-based IL + C 6 H 5 K 3 O 7 + alkaloids icotine 24 K Alk repulsive forces H + ph 7 ph 9 icotine Micelles is formation the most hydrophobic repulsive compound forces studied K ic stay inside of micelles 18

19 4.2. Self-aggregation in IL-based ATPS Imidazolium-based IL + C 6 H 5 K 3 O 7 Microscopy aplication ATPS composed of IL + Salt + H 2 O. Microscope image of IL-rich phase of ATPS composed of [C 8 mim]cl + C 6 H 5 K 3 O 7 + H 2 O. Confirmed the presence of micelles in systems composed of [C 7 mim]cl, [C 8 mim]cl and [C 10 mim]cl 19

20 4.3. Extraction of bisphenol A (BPA) Applications of BPA - Plastic industry as an intermediate in the production of epoxy resins and polycarbonate plastics; BPA - In the manufacture of thermal paper. However... BPA is an endocrine disruptor Production:3 million tons/year Release into the atmosphere: 100 tons/year Heart disease; Obesity; Breast and prostate cancer; eurobehavioral problems; Infertility; etc BPA is now an ubiquitous component in the atmosphere 20

21 4.3. Extraction of bisphenol A (BPA) ATPS composed of IL + K 3 PO 4 + H 2 O IL-based systems formed by the addition of K3PO4 provide high extraction efficiencies due to the presence of the strong salting-out salt 21

22 [IL] (mol kg -1 ) 4.3. Extraction of bisphenol A (BPA) ATPS composed of IL + K 3 PO 4 + H 2 O [C 2 mim]cl [4] [C 4 mim]cl [4] [C 6 mim]cl [4] [amim]cl [4] [C 4 mpyr]cl [K 3 PO 4 ] (mol kg -1 ) Cl- [P 4444 ]Cl + [ 4444 ]Cl [P 4444 ] + > [ 4444 ] + >> [C 6 mim] + > [C 4 mpyr] + > [C 4 mim] + > [amim] + > [C 2 mim] + >> [ 1112OH ] + - [ 1112OH ]Cl [5] [4] eves, C. M. S. S., et al, J. Phys. Chem. B 2009, 113, ; [5] Louros, C.L.S., MSc thesis, Extraction of Biomolecules with Aqueous Two Phases Systems, University of Aveiro, Aveiro, Portugal (2009). 22

23 4.3. Extraction of bisphenol A (BPA) ATPS composed of IL + K 3 PO 4 + H 2 O + + Aqueous Phase Artificial human urine [C 2 mim]cl [4] [C 4 mim]cl [4] 100 EE BPA % 99 + [C 6 mim]cl [4] [amim]cl [4] [C 4 mpyr]cl Cl- The presence of a more complex matrix, favors the partitioning [alkyl 1112OH side ]Cl of chain BPA Maximun length for the of IL-rich EE BPA EEphase % BPA % [P 4444 ]Cl - [ 1112OH ]Cl [5] [4] eves, C. M. S. S., et al, J. Phys. Chem. B 2009, 113, ; [5] Louros, C.L.S., MSc thesis, Extraction of Biomolecules with Aqueous Two Phases Systems, University of Aveiro, Aveiro, Portugal (2009). + [ 4444 ]Cl 23

24 [IL] (wt %) 4.3. Extraction of bisphenol A (BPA) TLL [IL] Optimization of amount of IL without losing the high extraction efficiencies of BPA [C 2 mim]cl [ 1112OH ]Cl [K 3 PO 4 ] (wt %) 100 Minimum concentrations: 15 wt % K 3 PO wt % [C 2 mim]cl 22 wt % K 3 PO wt % [ 1112OH ]Cl EE BPA % wt % 25 wt % 26 wt % 28 wt % 31 wt % 24

25 [IL] (wt %) 4.3. Extraction of bisphenol A (BPA) Maximum concentration of BPA achievable The concentration of BPA can be increased at least up to 100-fold [K 3 PO 4 ] (wt % ) 100 EE BPA % 99 [C 2 mim]cl [ 1112OH ]Cl IL IL IL Salt Salt Salt V IL [BPA] IL-rich phase 25

26 5. Conclusions The organic salt tri-potassium citrate showed to be a good option for the substitution of commonly used inorganic salts, in ATPS formation; For the first time: it was addressed the effect of micelles formation and their impact on the extraction of (bio)molecules (both charged and non-charged); Significant impact in extraction processes The application of IL-based ATPS shows to be an improved technique for concentrating the levels of BPA from biological fluids; For all investigated systems, extraction efficiencies of BPA are higher than 98.5 %. 26

27 6. Future work To study novel ATPS composed of IL and other organic salts and their potential in the extraction of different types of compounds; To understand better the mechanisms underlying to the micelle formation in these systems and their effect in the extraction process; To support the finding of the micelle-mediated extraction application of transmission electron microscopy (TEM); Extraction of BPA with IL-based ATPS: To work with real body fluid samples, aiming at providing a general overview of the levels of BPA in the Portuguese population and its relation with several types of diseases. 27

28 Acknowledgements Thank you for your attention! Path and Mini-Path Prof. João Coutinho Dr.ᵃ Mara Freire Ana Filipa Cláudio