"People started lining up at 5 p.m. and spent the night at the polling stations, " said Delalorm Sesi Semabia, 25, an oil company employee who lives in the capital, Accra.

CNN: STORY HIGHLIGHTS

The compounds in their breath were analysed using a technique called secondary electrospray ionisation mass spectrometry (SESI-MS), which is capable of detecting extremely small elements of the chemicals present in their breath.

BBC: Lung infection identified using 'breath-print'