Chemical profiling of the street cocktail drug 'nyaope' in South Africa using GC-MS I: Stability studies of components of 'nyaope' in organic solvents

Nyaope, a street drug commonly found in South Africa, is a mixture of low grade heroin, cannabis products, antiretroviral drugs and other materials added as cutting agents. It is a highly physiologically addictive substance which is smoked by users. Little work has been published on the chemical analysis and profiling of nyaope. Sample preparation prior to chromatographic or spectrometric analysis normally involves dissolution of the sample in an organic solvent. This study determined the most suitable organic solvent in which the common components of nyaope, namely Δ9-tetrahydrocannabinol, diamorphine, caffeine, dextromethorphan, phenacetin and the antiretrovirals efavirenz and nevirapine, which have different chemical characteristics, are stable during extraction and prior to analysis of nyaope samples i.e. autosampler stability. Street samples of cannabis (Δ9-tetrahydrocannabinol), heroin (diamorphine) and antiretrovirals were mixed to mimic a nyaope sample and dissolved in the organic solvents dichloromethane, ethanol, ethyl acetate, hexane, isopropanol and tertiary butyl alcohol. Analysis was performed after intervals of 0, 1, 6, 8, 24, 48 and 72 h, prior to analysis by gas chromatography-mass spectrometry. Tertiary butyl alcohol resulted in the most stable extracts of the main nyaope components after 72 h of storage. The analysis was also repeated on actual street samples of nyaope. These results show that tertiary butyl alcohol is a suitable solvent for sample preparation for the identification, comparison and profiling of nyaope samples.