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Our post on Mikhail Tsvet tells how chromatography began with leaf pigments sticking to chalk. The method you use with filter paper in a school lab works on a different principle, and it came from two British chemists trying to analyse wool. This post covers who Archer Martin and Richard Synge were, how a stubborn machine led them to partition chromatography, how their Rf value connects to a partition coefficient, and what Martin said about first experiments.
Who were Martin and Synge?
The Nobel facts pages record that Archer John Porter Martin was born in London on 1 March 1910 and died on 28 July 2002, and that Richard Laurence Millington Synge was born in Liverpool on 28 October 1914 and died on 18 August 1994. They shared the 1952 Nobel Prize in Chemistry "for their invention of partition chromatography".
Martin's Nobel biography says he worked on vitamin E at the Dunn Nutritional Laboratory in Cambridge and moved in 1938 to the Wool Industries Research Association in Leeds. Synge's biography says he was a research student in the Cambridge biochemistry laboratory headed by Frederick Gowland Hopkins, and joined Martin in Leeds in 1939. They first demonstrated partition chromatography to the Biochemical Society on 7 June 1941.
How did a failed machine lead to a new method?
Martin's Nobel lecture describes it as "the marrying of two techniques": chromatography and countercurrent solvent extraction, where two liquids flow past each other and a solute shares itself between them. As a PhD student he built a machine equivalent to about 200 separating funnels, coining what he called Martin's principle: "Nothing is too much trouble if somebody else does it". With Synge he then built a 40-plate extraction machine to separate acetyl amino acids between chloroform and water. It worked, but needed nursing day and night.
He tried packing a tube with wool and cotton, hoping water would cling to the cotton and chloroform to the wool. It failed. Thinking about why, he realised he did not need both liquids to move. Hold one still, move only the other, and the arrangement becomes a chromatogram.
What did the first partition column look like?
Their paper, A new form of chromatogram employing two liquid phases (1941), explains the idea: silica gel holds water as a stationary liquid, acting "merely as mechanical support", while chloroform flows through. Substances separate by differences in how they partition between the two liquids, "not, as in all previously described chromatograms, on differences in adsorption".
To see colourless acids, they added the indicator methyl orange to the water, and the acetyl amino acids showed up as red bands on an orange column. Martin's lecture adds a twist: when they carefully purified their chloroform, the bands stuck. The alcohol added to commercial chloroform as a stabiliser had been helping all along.
Worked example: from Rf to partition coefficient
In 1944 Martin, with Consden and Gordon, moved the method onto filter paper, where water held in the cellulose is the stationary liquid. Their paper, Qualitative analysis of proteins: a partition chromatographic method using paper, introduced the symbol Rf = movement of band ÷ movement of the advancing front of liquid, and related it to the partition coefficient α (concentration in water ÷ concentration in solvent):
Rf = AL ÷ (AL + αAS), where AL ÷ AS is the ratio of the volumes of solvent and water phases on the paper.
Rearranged: α = (AL ÷ AS) × (1 ÷ Rf − 1).
These are sample numbers for illustration. Take AL ÷ AS = 2.
Spot A has Rf = 0.40: α = 2 × (2.5 − 1) = 3.0.
Spot B has Rf = 0.60: α = 2 × (1.67 − 1) = 1.33.
Spot A prefers the stationary water a little over twice as much as spot B does, so it moves more slowly. For the measuring side of Rf, see our posts on purification and chromatography and Mikhail Tsvet.
Common mistakes to avoid:
Treating Rf as fixed. It depends on the solvent pair and conditions, which is why Martin's group logged amino acid positions in many solvents.
Inverting α. Here α is water over solvent. A larger α means a slower spot.
Mixing up the phases. On paper, the water held by the cellulose is the stationary phase and the organic solvent is the moving one.
If partition between two liquids is hard to picture, the Fermi Simulation Lab has interactive simulations for ideas that are easier to see than read.
Did they really predict gas chromatography?
Yes. The 1941 paper says plainly: "The mobile phase need not be a liquid but may be a vapour", and suggests passing a gas over gel soaked in a non-volatile solvent to separate volatile substances. Martin's 1952 lecture says no one seems to have taken it up until he and A. T. James did.
What can a student learn from Martin and Synge?
Learn from failure. The wool-and-cotton flop gave Martin the key idea.
Start rough. Martin wrote that "one should take a minimum of care and preparation over first experiments", because elaborate first attempts that fail are too discouraging.
Watch the hidden variable. A stabiliser in a solvent bottle decided whether the column worked.
Try it now: run green leaf extract on filter paper with two different solvents and compare the Rf values of the same pigment.
