Sonica Devi - BSc (Hons) Forensic Science
Sonica studied BSc (Hons) Forensic Science and as part of her final year research project she found minute traces of cocaine at a number of public phone boxes in the city of Derby.
Sonica's research
Sonica developed an ultra sensitive Gas Chromatographic technique allowing her to detect cocaine at picogram levels - one million millionth of a gram from forensic swabs. She used sterile swabs to collect samples from different areas of all six phone boxes including: the dial; handset; key pad and coin slot.
She then took the swabs back to the university laboratories for analysis and each of the swabs were placed in tubes containing a solvent called Dichloromethane (DCM). The solvent dissolves the cocaine and allows it to enter the Gas Chromatograph.
After separating the cocaine from other materials lifted by the swabs the mass spectrometer detector provides a means to detect the cocaine - using the method developed by Sonica this was performed with extremely high sensitivity.
The results
Sonica was able to see even the smallest of traces of cocaine within samples collected from around the city. The lowest amount Sonica was able to detect was fifty parts per million million - fifty picograms.
She discovered that in one phone box, cocaine was present at a much higher level of ten nanograms and in the other five phone boxes tested, cocaine was detected at varying levels approaching the limit of detection established using this approach - fifty picograms.
