Statistical analysis of trace metals content of cocaine using inductively coupled plasma-mass spectrometry calibrations

Abstract The trafficking of cocaine has become a global challenge now and Ghana is no exception. Cocaine is a whitish powder, which is, produced both from natural and synthetic means. This paper studied the metal content of seized cocaine in Ghana and the data used for batch identification. Ten metals, namely, Pb, Cu, Mg, Mn, Cr, As, Ni, Fe, Co and Ca were analyzed in 37 samples which were sampled from 2010 to 2014. Analyses of the metals were done using ICP-MS and data was analyzed using statistical tools. The results showed that, calcium recorded the highest amount in all the samples with a mean of 64.94mg/kg followed by Magnesium, Zinc and Iron with mean values of 24.35mg/kg, 6.25mg/kg and 2.65mg/kg, respectively. All the samples, within-seizure classification under class A showed to significant differences between each pair at a confidence level of 95%. With three sample pairs under class B in the within-seizure classification, one of the pairs; 103A and 105B showed no significant differences between them even though they were sampled from two different packages from the same seizure. Five samples from five different seizures also showed a significant difference among them showing that they came from different batches or origin. It is confirmed that seized cocaine contained poisonous heavy metals like Lead, Arsenic and Chromium, which have the amount that could affect the user-provide figures. Based on the data gathered from the within-seizure class A group, it could be proposed that a missing cocaine could be identified by its metal content.