At the far end of the tube, a detector measures the separated chemicals as they emerge, producing peaks on the graph paper. The exact profile of peaks not only depends on the injected sample, but on the choice of packing material, its particle size, the solvent or gas mixture used, the flow rate, the temperature, the pH and many other factors. Often, chemicals with entirely different chemical structures can have similar or identical affinity for a particular packing. This can cause peaks to blend into or superimpose on each other. Impurity peaks can get buried under the primary peak.
Precise technique is critical.
Chromatography is an art as well as a science. There would have been too many zeroes after the decimal point to be impressive. The six samples were reported to contain 2.9, 3.4, 6.5, 7.1, 8.7 and 14.1 percent of the amount found in case-implicated samples. The exageration of numbers was fully consistent with the blatant political motivations behind the letter. This is a fantasy.