RPLC/HILIC/API-MS: polarity extended analysis for organic molecules in water bodies

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1 RPLC/HILIC/API-MS: polarity extended analysis for organic molecules in water bodies Sylvia Grosse and Thomas Letzel Analytical Research Group Ixia, Rhodes, 1st September, 2015

2 content polarity extension RPLC with HILIC HILIC retention mechanisms: adsorption distribution (water layer) electrostatic interaction stationary phases and mobile phases in HILIC serial HILIC-RP-MS coupling application conclusion 2

3 Why polarity extension? Polar and nonpolar molecules Partition coefficient (P): Distribution coefficient (D): (For charged molecules) log P = log ([solute] oct /[solute] wat ) log D = log ([solute] oct /([solute] wat ionized + [solute] wat neutral ) Log P < 0 or Log D < 0 Log P > 0 or Log D > 0 Hydrophilic compounds Hydrophobic compounds Log P HILIC RPLC 3

4 HILIC Separation of polar and nonpolar compounds Hydrophilic analytes Hydrophobic analytes RPLC hydrophylic interaction liquid chromatography NP stationary phases RP eluents ACN/H 2 Reversed phase liquid chromatography Typical mobile phase H 2 /ACN RPLC vs. HILIC: rthogonal Use of the same solvents MS compatible 4

5 Retention mechanisms ADSRPTIN Analyte - Stationary Phase Hydrogen bonding Dipole - Dipole Si Si Si Si 5

6 Retention mechanisms DISTRIBUTIN increasing H 2 -content at least 2-3% water are essential in the mobile phase! Greco et al., J. Chrom. Sci,

7 Retention mechanisms ELECTRSTATIC INTERACTIN Electrostatic attraction Electrostatic repulsion 7

8 Stationary Phases Silica Diol, Amide, Cross-linked diol Aminopropyl Greco und Letzel, HILIC Solutions #3 uillarme, HILIC: a critical evaluation, 2014 Sulfobetaine 8

9 Stationary Phase: neutral Distribution Electrostatic interaction Adsorption R R NH 2 Amide n m H H Diol H H Cross-linked Diol H Greco et al., J. Chrom. Sci,

10 Stationary Phase: ionic Aminopropyl Distribution Electrostatic interaction Adsorption + NH 3 Anion exchange Si Si - H Silica ph < 4/5 ph > 4/5 Cation exchange Greco et al., J. Chrom. Sci,

11 Stationary Phase: zwitterionic Sulfobetaine (ZIC-HILIC) Distribution Electrostatic interaction Adsorption + N S - P N + - Phosphorylcholine (ZIC-cHILIC) weak Greco et al., J. Chrom. Sci,

12 rthogonality RPLC and HILIC 12

13 RPLC-HILIC coupling 13

14 No HILIC Polarity Extension RPLC HILIC RPLC 14

15 HILIC-RPLC application I: Amino acids Phe; 2 Leu; 3 Trp; 4 Ile; 5 Val; 6 Tyr; 7 Pro; 8 Thr; 9 Ala; 10 Asn 15

16 HILIC-RPLC application II: pharmaceuticals and neurotransmitter Gabapentin Betaine Vigabatrin 16

17 HILIC-RPLC application II: pharmaceuticals and neurotransmitter gamma aminobutyric acid? Acetylcholine? 17

18 HILIC-RPLC application II: pharmaceuticals and neurotransmitter smrm gamma-aminobutyric acid Standard EPI Fragment Spectra ratio Quan/Qual: 3.6 gamma-aminobutyric acid real sample ratio Quan/Qual:

19 HILIC-RPLC application II: pharmaceuticals and neurotransmitter smrm Acetylcholine Standard EPI Fragment Spectra ratio Quan/Qual: 8.9 Acetylcholine real sample ratio Quan/Qual: 4.2 r r 19

20 HILIC-RPLC application III: Sweetener and industrial chemicals, herbicide Cyanuric acid Acesulfam Isopentylamine Glyphosate 20

21 HILIC-RPLC application IV: An xidation Scenario with Diclofenac BDD electrode Diclofenac (DCF) MilliQ water Synthetic hard water Real wastewater effluent Sample collection: 0-60 min Rajab, Greco, et al., J. Sep. Sci

22 HILIC-RPLC application IV: Diclofenac oxidation Literature proposed transformation products Rajab, Greco, et al., J. Sep. Sci

23 HILIC-RPLC application IV: Diclofenac oxidation Rajab, Greco, et al., J. Sep. Sci

24 HILIC-RPLC application IV: Diclofenac oxidation TP_34 TP_27 rganic transformation products TP_41 TP_26_A TP_46 TP_4 TP_8 TP_6 DCF Cl 4 - Inorganic compounds Cl Counts vs. Acquisition Time (min) 24

25 conclusion Understanding of HILIC mechanisms HILIC valid with logd value < 0 extended polarity with serial RPLC-HILIC coupling Combination of different chromatographic techniques in just one technique (RP, GC, IC) A new field of molecules is taped and will give a lot more interesting results 25

26 Dr. Giorgia Greco Dr. Mohamad Rajab Sofia Veloutsou Prof. Dr. Drewes and the whole team Thanks... Funding: This work was partially financed by the German Federal Ministry of Education and Research within the RiSKWa program, funding code 02WRS1354A. Funded by: 26

27 Thanks... And for your attention... Any questions??? 27