19 Figure 7 Figure 9
Conclusions Liquid-Liquid Chromatography has matured into a valid science, which after almost 60 years deserves to be integrated into mainstream laboratory and process chromatography. L-LC been shown to compliment HPLC, with narrow range polarity cutting and by helping to find peaks co-eluting in HPLC. One beauty of L-LC is that the separation is based largely on defining on the polarities of targets, therefore classes of compounds can be separated which can then be optimised without sample loss. These narrow polarity range classes can finally be passed through a HPLC, assuming sample losses can be tolerated. If not, Sequential L-LC to L-LC with different solvents may be utilised. L-LC is a low- pressure technique (typically 100 to 500 psi) thus it can use lower price ancillary equipment than HPLC. L-LC usage has the potential for considerable solvent cost and timesavings.
References 1) Leitao G.G., El-Adji S.S., Melo, W.A., Leitao, S.G., Brown, L., J. Liq. Chromatogr. Relat. Technol. (2005) 28, 2041-2051
Figure 8
the initial loading to closer to a typical 5 to 40g loading per 1000 ml.
C ase Study Wine Research Fig 7, 8, 9 & 10 by wine researchers (5) shows the worth of gradients in L-LC, and of L-LC in unravelling difficult identification issues. This research led to the targets sensory properties being determined and tentative structural elucidation of new unknown oligomeric anthocyanins. The chromatogram on HPLC revealed an absence of standard baseline hump seen once the monomers etc were
Figure 10
separated by L-LC. This highlights the value of doing a L-L chromatography sample polarity screening. L-LC helped these wine researchers to identify a new class of compounds (oligomeric anthocyanin species), and to study their influence to the colour and sensory properties in wine.
Case Study 7 HTPrep/Combinatorial. In 2007 we custom designed the World’s first Quattro HTPrep™ for a Pharmaceutical Company in the USA. The research was presented at CCC2008 and published in the proceedings (6).
2) Leitao G.G., Souza, P.A., Moraes, A.A., Brown, L., J. Liq. Chromatogr. Relat. Technol. (2005) 28, 2053-2060
3) Comprehensive Analytical Chemistry XXXVIII, A Berthod (Ed) (2002), Countercurrent Chromatography, Chapter 2, Berthod A, Brown L, Leitao G.G, Leitao. S.G.
4) Silva J.C.T., Jham G.N., Oliveira, R.D. L., Brown, L., J of Chrom A (2007), 1151, 203-210
5) Vidal S., Hayasaka, Y., Meudec, E., Cheyner, V., Skouroumounis, G.,
J.Agric. Food Chem. (2004), 52, 713-719
6) Wangenaar F.I., Hochlowski, J.E., Pan, J.Y., Tu, N.P., Searle, P.A, J Chrom A, 1216 (2009) 4154 – 4160.
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