A validated ICP-MS method for the screening and quantitative analysis of heavy metal contaminants in home-brewed alcoholic beverages of Botswana

Abstract

A method for the analysis of heavy metals in homemade alcoholic beverages using an Inductively Coupled Plasma-Mass spectrometry (ICP-MS) was developed and validated for accuracy, precision, linearity, limit of detection and quantification. Linearity was discovered to be in the concentration range of 10–50 (ppb) with correlation coefficient (R2) of above 0.99 for all the seven detected metals. The method is precise with %RSD values ≤ 5 %. Limits of detection and quantification were 0.01–0.16 and 0.10–1.6 (ppb), respectively. The accuracy ranged from 95.1 % to 105.3 %. Thirty-two samples of locally brewed homemade alcoholic beverages and five commercial samples were subsequently analysed using the method. The detected metals included manganese, cobalt, chromium, copper, zinc, aluminium, and lead. The concentrations of Aluminium and Lead in some homemade samples exceeded the set maximum allowable limits (MAL) of the World Health Organisation. The carcinogenic and non-carcinogenic human health risk assessments were also performed for the detected heavy metals. The carcinogenic risk analysis revealed that chromium and lead values were above the safety level of 10−4 set by the United States Environmental Protection Agency (USEPA) in some samples. This suggests that the two metals can pose potential cancer risks to consumers. There were no apparent non-carcinogenic health risks associated with the studied heavy metals. The results obtained from this study will contribute to the growing body of literature regarding the safety of homemade alcoholic beverages around the world.