Trends in HPLC column technology and their application

Transcription

1 Trends in HPLC column technology and their application About long Columns and small Particles S. Lamotte, GMC/C HPLC 0 Amsterdam 6 th -0 th June 0

2 Outline sub µm particles in fast HPLC: A critical view! long columns: Is this the solution? Superficially porous particles: How about that? Monolithic Columns: How is their performance? The new generation of sub µm particles Conclusion: What really counts!

3 Comparison.7 µm vs. µm d p =.7 µm F = 0.6 ml/min u =.8 mm/s p = 0 MPa d p = µm F = 0.6 ml/min u =. mm/s p = 7 MPa d p = µm F =.0 ml/min u = 8.0 mm/s p = 0 MPa

4 Comparison p = 0 MPa.7 µm vs. µm Acquity BEH C8,.7 µm 00 x. mm R s : R s : 0.7 XBridge BEH C8, µm 00 x. mm R s : R s : F = 0,6 ml/min F =,0 ml/min Injection: µl Injection: 9 µl Mobile Phase: MeCN/H O 70/0 (v/v) Sample: Toluene, Ethylbenzene, Propylbenzene, Butylbenzene, Pentylbenzene

5 Influence of extra column band broadening Sample dissolved in mobile Phase Sample dissolved in MeCN/H O /7 (v/v) Column: Aquity BEH C8,.7 µm 00 x. mm Mobile Phase: MeCN/H O 70/0 (v/v) Flow rate: 0,6 ml/min, p = 0 MPa Sample: Toluene, Ethylbenzene, Propylbenzene, Butylbenzene, Pentylbenzene

6 Influence of extra column band broadening Sample dissolved in mobile Phase Sample dissolved in MeCN/H O /7 (v/v) R s :. R s : 6.8 R s :. R s : Column: Aquity BEH C8,.7 µm 00 x. mm Mobile Phase: MeCN/H O 70/0 (v/v) Flow rate: 0,6 ml/min, p = 0 MPa Sample: Toluene, Ethylbenzene, Propylbenzene, Butylbenzene, Pentylbenzene

7 Faster EPA Method Mix Aquity BEH C8,.7 µm 00 x. mm XBridge BEH C8, µm 00 x. mm F = 0.60 ml/min p = 6 MPa, T = 0.7 C u =.6 mm/s F =.00 ml/min p = 00 MPa, T = 70.0 C u = 8. mm/s 6 7 8

8 Higher Efficiency EPA Method Mix Aquity BEH C8,.7 µm 00 x. mm XBridge BEH C8,. µm 00 x. mm F = 0,60 ml/min p = 6 MPa, T = 0,7 C u =.6 mm/s F =,70 ml/min p = 00 MPa, T = 70,0 C u = 9.8 mm/s

9 Conclusion Sub µm vs. µm Particles Sub µm particles packed in shorter columns show higher mass sensitivity but no higher over all sensitivity compared to conventional formats UHPLC leads to lower solvent consumption compared to conventional HPLC UHPLC has no significant improvements in speed of analysis UHPLC suffers in practical restrictions: extra column band broadening solvent strength effects dirty samples conventional HPLC formats show high efficiency loss (approx. 0%) at very high linear velocity

10 Are there any Alternatives?

11 In between porous and non porous Superficially porous particles.7 µm fused core. µm porous µm porous N / meter.7 µm fused core (non porous) 0. µm porous layer.7 µm particle size Back pressure of a.7 µm particle column Efficiency of a sub µm particle column Source: AMT Inc.

12 Comparison p = 0 MPa.7 µm vs. Superficially Porous.7 µm sub µm 00 x. mm F = 0,6 ml/min u =, mm/s Superficially porous 0 x.0 mm F =, ml/min u =,8 mm/s Mobile Phase: MeCN/H O 70/0 (v/v) Sample: Toluen,e Ethylbenzene, Propylbenzene, Butylbenzene, Pentylbenzene

13 Comparison p = 0 MPa different superficially porous materials Kinetex C8,,6 µm 0 x.0 mm F =, ml/min u =,8 mm/s Halo C8,,7 µm 0 x.6 mm F =,6 ml/min u =,6 mm/s Mobile Phase: MeCN/H O 70/0 (v/v) Sample: Toluene, Ethylbenzene, Propylbenzene, Butylbenzene, Pentylbenzene

14 The concept of monolithic columns Optimizing the efficiency/back pressure ratio large porous particles: low back pressure slow mass transfer small porous particles high back pressure fast mass transfer Monolithic Structure: Hybrid of wide chanels with small cross linked particles (sponge) low back pressure fast mass transfer

15 Chromolith Design (Merck) how the rods are looking like? and in detaill? Source: Merck KGaA Flow through pores Meso pores

16 Comparison N = Sub µm vs. Monolith 00 p = 0 MPa Aquity BEH C8,.7 µm 00 x. mm F = 0,6 ml/min u =, mm/s p = 0 MPa Chromolith High Resolution 00 x.6 mm F =, ml/min u =, mm/s

17 Comparison Sub µm Materials Titan C8,.9 µm 00 x. mm Acquity BEH C8,.7 µm 00 x. mm k = k = p =9 MPa (psi) u =. mm/s p = MPa (700 psi) u =.7 mm/s Flow rate: 0. ml/min Mobile Phase: MeCN/H O 70/0 (v/v) Sample: Toluene, Ethylbenzene, Propylbenzene, Butylbenzene, Pentylbenzene

18 Conclusion Titan C8 has higher retention und loadability compared to Acquity BEH C8 (0%) Titan C8 has % less efficiency compared to Acquity BEH C8 Titan C8 has % less back pressure compared to Acquity BEH C8 Interesting alternative for higher loadability and the possibility to cover a wider polarity range in UHPLC

19 Summary Comparison Parameter Classical Particles Sub µm Superficially porous Monolithic Max. N N/t N/bar Solvent savings Robustness Loadability Pressure drop

20 Resolution in Chromatography R S = N k + k α - α α k N,0,,0,,0,,0 α k N

21 Resolution Selectivity is the key What parameters are influencing selectivity? Stationary Phase C8, C8, Phenyl, Polar Embedded Analyte Mobile Phase Type of solvent (MeOH, MeCN ) Additives (TFA, TBA, SDS ) ph Temperatur

22 Summary sub µm particles have an excellent efficiency per time unit ratio and help to save solvent and waste Classical columns show no significant slower separations (if driven at same pressure drop) but are more robust Superficially porous particles are alternatives for high efficient or fast separations Monolithic columns provide best efficiency per pressure drop ratio and robust separations Nether the less: HPLC separations are made via selectivity and not via plates!!!

23 Acknowledgement Analytical Tasks GC HPLC/GPC SFC CE Know how & Equipment Motivated Coworkers B. Frosch, A. Güntner, F. Leinweber, W. Stegmaier, K. Euler, K. Krempel, S. Lamotte, S. Staal, D. Weller, R. Beringer, G. Bretscher, S. Ehinger, M. Flink, V. Gerber, T. Grill, B. Kamb, S. Simon, A.-V. Huynh, B. Prescha, M. Reuther, C. Spieß, Al. Weber, M. Weyler, Al. Blum, S. Diehl, C. Mayer, E. Ramos, G. Schenk, U. aus der Wiesche, S. Bernbach, J. Bohn, K. Braun, K. Jester, J. Nowack, R. Scheidhauer, J. Schröder, U. Stauder, R. Stritesky, M. Weidenthaler, S. Gräning, K.-E. Horn, K. Horr, P. Kahne, M. Mees, A. Mehrl,W. Schädler, R. Stawinski, A. Fornalski, C. Glanzer, B. Klein, H. Lembach, M. Meckes, B. Neumann, H.-N. Nguyen, G. Scheidhauer, H. Schilling, N. Schläfert, R. Stemmler, M. Zehfuß, G. Böse, R. Erker, C. Gödtel, H. Hauck, M. Liebig, Y. Mattheis, B. Riedel, M. Scholz, K.-F. Bengel, T. Benker, H. Boos, S. Casper, R. Eberle, T. Gieger, S. Heckmann, R. Johne, J. Kraft, F. Metzger, G. Metzmann, M. Monte-Schwab, S. Oehmig, C. Rasch, B. Schmitt, H. Schulzik, M. Schurhammer, M. Siegmund, S. Tutino, An. Weber, H. Zeitler, H. Althaus, R. Baas, K. Brauer, P. Brock, V. Butt, T. Dolich, M. Dürk, E. Helt, J. Kammer, A. Mundt, M. Neumann, S. Schalter, E. Sensen, K.-D. Vuong