The Future Revisited

Peter Myers, Department of Chemistry, University of Liverpool, Liverpool, UK.

Peter Myers ponders the future from the University of Liverpool.

On the occasion of the Golden Jubilee of The Chromatographic Society, Peter Myers wrote “The Future of Chromatography” in The Chromatographic Society’s souvenir brochure. Now Peter revisits his chromatographic crystal ball to review his predictions and deliberate on what the future might now hold for separation scientists.

For the Golden Jubilee of the Chromatographic Society in 2006, I wrote a small article on the future of chromatography. I thought it might be nice to review this after 10 years to see if I got anything correct.

In the 2006 article I talked about the new monolithic columns that offered a lower back pressure for the same plate count as a classical particle-packed column. I also discussed the introduction of sub-2-µm particles that offer higher plate counts but at the expense of far higher back pressures. I asked the question “Are either of these the future of chromatography? Well let me make my first bold statement and say no.” I think I was correct -particularly with monoliths and to a great extent with sub-2-µm particles. Today I still believe sub-2-µm particles may be OK for the super clean samples found in the pharmaceutical industry, but in the real world we still have dirty samples and these are still best handled by columns packed with 5- or 3-µm particles.

After these two points I’m afraid I got things wrong - well maybe not wrong, just that there haven’t been the developments I expected. For example, I had hoped to have seen new on-column injectors and on-column detectors. We still do not have these, but maybe we are seeing a move to a new form of UV detector through the work of Paraytec. Set up by David Goodall on his retirement from the University of York, Paraytec is “a scientific instrument company, developing and manufacturing miniature UV–vis absorbance detectors based on patented technology”. Maybe my prediction failed because I didn’t foresee the growth of the mass spectrometer as the detector of choice and the reduction in price of mass spectrometers for chromatography. However, I am now starting to see a new move in liquid chromatography (LC) into some instrument miniaturization and the move to make portable LC instruments for field use.

But my main point was that I hoped we would have intelligent columns by now. My argument was based on the fact that the column is the heart of any separation system. The columns should therefore carry a smart chip not only to identify the column but also to carry the method, so that we no longer need to purchase a C18 column but a column for PAH analysis or a column for basic drugs. The column will be placed inside the instrument and it will be the column that will set up the system parameters, perform QC procedures and calibrations, and finally decide when it requires replacing. We haven’t seen anything like this yet and we certainly have not seen new micro- and nano‑fabrication techniques to make columns such that a whole range of functions can be integrated into a single column format.

I also tried to look forward into the real future and in this I had hoped we would see the end of the chromatography column and the high pressure pumps for analytical separations. I hoped we would have moved into nonmechanical pumping systems using electroosmotic flow. I was wrong. We are still using pumps and general columns with different bondings are still the centre of our separations. All that has changed is that we have smaller particles and some different porosities. The pump is still king. Unfortunately, I cannot foresee a change to this, because today’s instrument manufacturers are really pump manufacturers.

We have, however, seen a small change in the reduction of the internal diameter (i.d.) of high performance liquid chromatography (HPLC) columns. In 2006, 4.6-mm i.d. columns were still the most popular; today this is changing to 2.1 mm and 1 mm. Why is this taking so long? Research leaders have been shown the advantages of smaller internal diameter for over 10 years. Again I put the blame back on the instrument and column manufacturers. When using a smaller internal diameter column, more care has to be taken to connect the small and even smaller capillary columns into the instrument to avoid dead volume. The fittings we use today are just not fit for modern use. They are essentially the same format as the fittings used over 10 years ago with a frit and a modified Swagelok fitting. We need new fittings with snap on or simple pressure fittings. But again, we need the instrument and column manufacturers to make a step change in their column or instrument design. I do hope this will occur in the next 10 years. But as you know, I have been wrong before!

So how do I foresee the future now? Unfortunately, I don’t think changes are going to come fast. But it could if someone embraced the new nanotechnologies using sensors (nanowires), electroosmotic flow on controlled surfaces, and electrically controllable bonded phases. We have to get the instrument and column manufacturers to move out of the separation science box in which they are happy and profitable. I hope they will look at what is happening in some universities (especially Liverpool!).

For yourselves, read all about the new sensors, materials, and flow induction methods in the new journals and you will see how we as separation scientists are being left behind modern technology.

I hope in another 10 years I can write “Do you remember when we used to use pumps and packed columns for HPLC?”!

Peter Myers is currently a Visiting Professor of Chemistry in the Department of Chemistry at the University of Liverpool, in Liverpool, UK, and a Chromatographic Society Martin Medallist.