Raman spectroscopy used to identify counterfeit drugs
Breakthrough approach can identify fakes while inside their packaging; researchers at the Rutherford Appleton Laboratory adjust the collection point a few millimeters in front of the laser signal; tests on paracetamol and ibuprofen prove the concept
In our rankings of the world’s most evil criminals, we include child molesters, mass murderers, and serial rapists near the top. Yet there is one group we place even higher, for their crimes are motivated solely by the profit motive, unlike the others who are driven mainly by more pschologically complex intentions. We are speaking of counterfeit drug manufacturers and dealers — those who package useless chemicals in the form of well known AIDS and cancer medications. (We exclude the homeopathic industry, for now.) Such charlatans do more than sell a fraudulent product; they kill people who might otherwise have lived if they had received real medication. Many others die because the counterfeit drugs contain dangerous impurities.
Fortunately, scientists at the Rutherford Appleton Laboratory in Didcot, United Kingdom have developed a method of identifying fakes while concealed within their packaging. (A legitimate-looking wrapper is far more important to the criminal’s plans than a authentic looking pill.) As with many advanced detection systems these days, the Rutherford detector uses a variant of Raman spectroscopy. This approach uses laser light to collect infrared reflections from sample chemicals, each of which emits a unique range of frequencies, producing a unique spectral fingerprint for that substance that is collected at the exact point were the laser is focussed. Up until now, however, this approach was useless if the chemicals being detected were encased in packaging.
To overcome this, the Rutherford researchers modified their spectrometer to collect the reflected signal at a slight distance from the point where the laser is focused. According to New Scientist, “this works because Raman signals generated deep within a sample shift sideways slightly before exiting the surface, unlike those generated on the surface itself. The signal from the packaging surface is effectively diluted, while that from the drug inside is amplified.” The idea is to go in sideways and avoid the blinding signal from the surface. The scientists have succesfully tested the method on paracetamol and ibuprofen, both in blister packs and plastic containers.
-read more in Andy Coghlan’s New Scientist report
