Analysis of Methanol Content in Locally Produced Distilled Spirits Sold in South East Nigeria

Illicit and informally produced distilled spirits, commonly referred to as ogogoro or kai kai in South East Nigeria, have been associated with numerous cases of acute methanol poisoning and fatalities in recent years. Methanol, a toxic by-product of fermentation using plant materials with high pectin content, can accumulate to dangerous levels when distillation is poorly controlled. This study determined methanol concentrations in locally produced distilled spirits collected from producers and market sellers in five communities across Abia and Imo States. Fifty samples were collected and analysed by gas chromatography with a flame ionisation detector using a validated headspace injection method. The permitted methanol limit for spirits under WHO guidelines of 3 g/L of absolute alcohol was used as the reference standard. Methanol concentrations ranged from below the detection limit to 18.6 g/L, with 46 percent of samples exceeding the WHO limit. Twelve samples had methanol levels above 5 g/L, presenting acute toxicity risk with regular consumption. Ethanol concentrations were also measured, ranging from 28 to 64 percent v/v. A negative correlation between ethanol content and methanol proportion was observed, consistent with methanol dilution at higher ethanol yields. The results highlight a critical public health issue and underline the need for regulatory action against unregistered distilleries, community education on the risks of informally produced spirits, and investigation of production practices to identify high-risk fermentation substrates in South East Nigeria.

Keywords: methanol poisoning, illicit spirits, distilled alcohol, gas chromatography, South East Nigeria