[Belfast]

I am not a specialist in chemistry. My question is about terminology. Is two-dimensional chromatography the same as two-way chromatography or are they two different things? If they are different, can anyone give me a heads-up as to how the two procedures differ? Thanks!

[Arkcon]

Two-dimensional chromatography is a common term, meant to denote two modes applied to one sample in series.  That is, separate once, then separate each fraction another way.

On a TLC plate, that's easy to visualize, just rotate 90 degrees and do the same thing again with different eluents.  But now, with advanced switching and automated peak selection, 2-D HPLC, for example, is becoming pretty hot.

Two-way is something I've never heard of, but it may be an older way of describing the new 2-D HPLC.  What context can you give us about the terms?

[Belfast]

Thanks very much for that, Arkcon. I think it must be the same thing. I don't know a lot about it, unfortunately, but I did find this on line:

Two Way Chromatography:
If two different substances have similar Rf value, they can be separated by the use of two way chromatography. A chromatograph is prepared starting from a single spot. The position of the solved front in marked with pencil as SF1.
 
When the paper is dried up completely, it is rotated by 90° and chromatograph is developed again with a different solvent. The position of the second solvent front is marked SF2. As can be seen here the spot No. 2 in the second chromatogrpah has been separated into two separate compounds using different solvents though they have same Rf values in the first chromatogram. Therefore the mixture having the similar Rt value can be separated by this technique.
Rf value of each of the compounds (spot) can be worked out and by comparing these with the known Rf value of different compounds, the compounds can be identified.

Is this the same thing? Thanks again for your *delete me*

[Belfast]

That should have read 'help', of course ... :-)

[Belfast]

Hi, Sorry about this, but I'm still not sure about this. Am I right that these two terms are synonymous? Can anyone confirm that for me, please?

[Arkcon]

Your definition of 'two-way chromatography' is the same as my definition of '2-D chromatography'.  You can look up 2-D chromatography in a reference book or text book, and confirm that.  I said that 'two-way chromatography' may be an archaic term, or it may be jargon for some application, or a poor translation.  Heck, it could even be a made-up term that no one uses.  I can't help you more than this.

[Belfast]

Thanks for that!  As I say, I am not a chemist and the explanations sometimes don't make much sense to people who have never been in a laboratory and done these procedures. I am quite happy to accept that two-way and two-dimensional chromatography are the same thing. I will keep the membership of this forum going - I'm sure I will have other questions in future. All the best!