Here’s a problem for you: What do you get if you add a solute to a solvent? That’s right, you get a solution. But that doesn’t mean you can dissolve every problem.
When I was a student, I had a summer vacation job at the Laboratory of the Government Chemist, an official establishment that analyses goods arriving in the UK to determine whether an import tariff is due. I spent four summers there altogether, first in the textile section, then the inorganic section and finally the organic section (twice).
The last two years in ‘organics’ were the most fun. In the majority of cases, it was clear from the import manifest what substance we were dealing with, and it was just a question of confirming that it was what the importer had claimed. Sometimes, though, we had a sample that was just listed as ‘chemical’, or some equally vague description. One of my samples was a black powder, and the only information about it in the accompanying documents was its trade name. An initial search of the appropriate trade directory failed to find a match, so I put on my metaphorical detective’s hat and started to run some tests.
The standard procedure at the time was to start by getting an infra-red spectrum of the unknown substance. To do this, you dissolve a sample of the substance in a volatile organic solvent, smear some of the solution on a salt disc, allow the solvent to evaporate and place the disc in an IR spectrometer. The machine would produce a wiggly red line on a long piece of paper, and the chemist would compare the absorption peaks with known substances. Some functional groups are easy to spot because they create large, sharp peaks; others produce less distinctive patterns. But, as long as there was no water in the sample, it gave you some idea of what you were dealing with.
So, I tried to dissolve my mystery substance in chloroform. It sat resolutely at the bottom of the test tube and refused to disperse no matter how hard I shook it. The same thing happened using ether and carbon tetrachloride as solvents. Now, this is quite unusual for an organic compound, and it presented a bigger problem than I was expecting.
The next step in the procedures manual called for a technique known as pyrolysis. This is a rather crude method, primarily used to characterise natural and artificial rubbers. You put your material on a spatula, heat it in a Bunsen flame and catch the fumes on an IR sample disc. Polymers like rubber create a tarry deposit that has a messy IR spectrum that is suggestive of particular types of polymerisation methods. More than that, you cannot say.
When I tried this, my black powder remained apparently unchanged even when the spatula was glowing red hot. It produced no fumes, no smoke, no volatile material that could be deposited on the IR disc. It didn’t catch fire in the Bunsen flame, either. This was some fearsomely obstinate stuff.
At this point, I was beginning to wonder if my substance ‘X’ had gone to the wrong section of the laboratory; perhaps it wasn’t a carbon compound at all. The lab did, of course, have other analytical methods at its disposal: X-ray crystallography and Nuclear Magnetic Resonance imaging, for example. But those were expensive and had specialist uses – they were not appropriate for what should have been a routine sample. So, I went back to the trade directories. This was in the 1970s, before the Internet and search engines. My task was to trawl through the volumes of big, heavy tomes in the library in the hope of finding some information on the trade name of the material that was hiding its character behind a powder black cloak of secrecy.
And that proved to be the breakthrough that I needed. There, in black print on faded white paper, were a few paragraphs on the material in the sample bag downstairs in the lab. The text described the basic properties of the product and gave its chemical formula. Substance ‘X’ was a carbon compound with multiple interconnected carbon rings, resembling a portion of a graphite sheet and with no reactive groups. It was a lightbulb moment. If you have a basic knowledge of carbon chemistry, and you imagine the graphite from a lead pencil ground to a powder, you will understand why my mystery substance behaved as it did.
There didn’t seem to be anything else the lowly vacation student could do, so I just reported my findings to my supervisor, who accepted the sample as genuine and left me to move on to the next packet or vial to be tested.
At about the same time as the Crotchety Lad was messing about in a government lab, there was a Solution making music in the Dutch town of Groningen. This particular Solution was a prog/fusion band. Their first album, also called Solution, was released in 1971.
This album is very much of its time, with strong influences of west coast U.S. psychedelia audible within the bulk liquid styles of prog and fusion. And most enjoyable it is, too. It has taken some 50 years to filter across from the European continent to the Crotchety region of the UK via a post on the Australian blog site, Vinyl Connection. So, thanks go to Bruce Jenkins for bringing it to my attention.
I’m sure Einstein was right when he said that understanding a problem is the most important step on the path to its solution.
Crotchety Man 