Study of Inorganic Profiles of Street Cocaine Samples Using ICP-MS and ICP OES

Determining inorganic constituents in illicit drugs can indicate its purity and presence of adulterants. In this study, we analyzed 52 street cocaine samples, seized in three different regions of Espírito Santo, state of Brazil. Inductively coupled plasma optical emission spectrometry was used to determine Al, Ca, Cu, Fe, Mn, Mg, Zn concentrations and inductively coupled plasma mass spectrometry to determine Mo, Co, Pb and P concentrations. From analyte recovery tests, the accuracy was considered acceptable and the proposed method satisfactory. Most of the samples exhibited a relatively homogeneous inorganic profile with similar concentrations of investigated elements, however some samples had very discrepant concentrations. High concentrations of Al, Ca, Fe, Mg, Mn, and P were found, indicating that adulterants such as gypsum, marble powder, limestone, cement, and others must be used to increase the profitability of the illicit drug market.

Keywords:
inorganic elements; cocaine; ICP-MS; ICP OES; multivariate analysis