Qualitative Analysis
Checking for cheats
During the 2004 Athens Olympics, three people were stripped of their medals after failing a drug test. Twenty-one other competitors also violated doping regulations. So how did they get caught?
Athletes have to give a sample of their urine to the Olympic committee. Various chemical analyses are then carried out to look for traces of banned substances. On some occasions a blood sample is also analysed.
Some tests simply tell us if a substance is present. These are qualitative tests. Others find out how much of a substance is present. These are quantitative tests.
To make sure the laboratories conducting the tests do so properly and fairly, an organisation called the World Anti-Doping Agency (WADA) makes sure worldwide standards are met.
Chromatography
Chromatography separates and identifies the substances in a mixture. The most simple (and cheap) forms are paper chromatography and thin layer chromatography (TLC). You’ve probably come across both of these doing science at school.
Paper chromatography is pretty crude, and it’s not used that much outside the school lab. But thin layer chromatography is often used in forensic labs to analyse inks, fibre dyes and illegal drugs, especially cannabis.
In the school lab, paper and thin layer chromatography are used to tell what substances are present in a mixture. More sophisticated chromatography techniques can tell us how much of each substance is present. They’re called gas-liquid and high-performance liquid chromatography (you can read more about these in “Quantitative Analysis”).
Hitler’s forged documents
Chromatography helped solve the case of the forged Hitler diaries back in the 1980s.
Twenty-seven volumes of Hitler’s personal diary were sold for about one-million pounds to the editor of a German magazine. Even though he hired experts to check their authenticity, the German police remained unconvinced.
They used chromatography to identify four inks – none of which had been available when Hitler was alive. Further analysis showed the ink was less than a year old.
They also discovered fibres made of viscose and polyester, artificial fabrics not around in Hitler’s time. The experienced forger was eventually caught and imprisoned.