Alcoholic beverages produced on the local black market in Iran are not safe at all. The application of the new method is convenient, fast, simple and accurate to assess the risk of toxicity of methanol in suspect alcoholic beverages. The reference method for determining the methanol content of alcoholic beverages is gas chromatography (GC). However, this technique is expensive, requires considerable knowledge and experience, and is not readily available in many developing countries, although this technique has even been used in mass poisonings before [5]. Access to a safe, inexpensive and simple method to detect the absence of unauthorized amounts of methanol prior to ingestion is therefore highly beneficial [6]. Hassanian-Moghaddam H, Zamani N. A brief overview of toxic alcohols: management strategies. Iran J Kidney Dis 2016;10(6):344–350. Rentence. PubMed PMID: 27903992. The objective of the present study was first to assess the methanol and ethanol levels of alleged alcoholic beverages discovered by Iranian police as a sample of alcoholic beverages available on the Iranian black market using GC as a reference method. As a second objective, we evaluated the toxicity efficacy of these suspect samples by detecting the relative methanol-ethanol content using a new kit based on a modified KT method and compared them to GC results to determine the effectiveness of the designed kit. Methanol and ethanol are very similar compounds from a biological point of view.
In fact, they have the same target structures and have a very similar organic effect.[9] However, while ethanol is oxidized to harmless acetate in the process, including conversion to acetyl-coenzyme A and subsequent oxidation via the Krebs cycle, formate is the end product of methanol oxidation. Formiate is a chemical toxin that can react with several target structures such as mitochondrial cytochrome oxidase [9]. In addition, formate is responsible for two typical manifestations of methanol poisoning: retinal dysfunction, followed by irreversible damage and metabolic acidosis [10][9]. The accumulation of methanol in the blood can cause hyperosmolality, and the accumulation of its metabolites can lead to an increase in the anion breach and a decrease in the serum concentration of bicarbonate, and this abnormality is an important diagnostic indication of methanoline toxicity. In addition, the accumulation of lactic and formic acid, formaldehyde and ketones leads to metabolic acidosis and promotes retinal damage [11]. Rehm J, Kanteres F, Lachenmeier DW. Unrecorded consumption, alcohol quality and health consequences. Drug Alcohol Rev 2010;29(4):426–436.
Rezension. The methanol content of suspect alcoholic beverages transmitted to the forensic toxicology laboratory in Gilan Province, Iran, was measured by gas chromatography and a recently developed kit based on a modified colorimetric chromotropic acid method. Pajoumand A, Zamani N, Hassanian-Moghaddam H, Shadnia S. Can the duration of haemodialysis be estimated on arrival on the basis of laboratory tests and clinical manifestations in patients with methanol poisoning? Int Urol Nephrole. 2017;49(6):1057–62. Tulashie SK, Appiah AP, Torku GD, Darko AY, Wiredu A. Determination of concentrations of methanol and ethanol in local and foreign alcoholic beverages and foods (Banku, Ga kenkey, Fante kenkey and Hausa koko) in Ghana. Food contamination.
2017;4(1):14. Out of 1221 samples, 145 (11.9%) did not contain ethanol, while in three samples (0.25%), methanol was high enough (700,000; 870,000; 920,000 mg/L) to cause severe methanol toxicity. The median ethanol content [IQR] of the suspect samples was 9% [3.7, 32.75]. Methanol was detected in 128 samples (10.48%) with the gas chromatography method and 160 samples (13.1%) with design kit with 100% sensitivity, 97.07% specificity and 100% negative predictive value. Methanol, a potent toxin in humans, is naturally present at low levels in most alcoholic beverages without causing harm. However, illicit beverages made from “industrial methyl spirits” (5% (v/v) methanol: 95% (v/v) ethanol) can cause serious illness or even death. Given that there is no literature in the literature indicating a no-harm-effect level for methanol, a key public health issue is what is the maximum concentration of methanol in an alcoholic beverage that an adult human could consume without risk of toxicity due to its methanol content. Published information on methanol-intoxicated patients is reviewed and combined with the results of studies in volunteers who received small doses of methanol and occupational exposure limits (OELs) to indicate a tolerable (“safe”) daily intake of methanol in an adult of 2 g and a toxic dose of 8 g. Concomitant ingestion of ethanol has no appreciable effect on the proposed “safe” and “toxic” doses when multi-hour exposure is considered.
Assuming that an adult consumes 4 standard 25 ml sizes of a beverage containing 40% vol. alcohol over a 2-hour period, the maximum tolerable concentration (MMC) of methanol in such a beverage would be 2% vol. (v/v). However, this value only allows for a safety factor of 4 to cover the variation in amount consumed and the effects of malnutrition (i.e. folate deficiency), disease and other personal factors (e.g. ethnicity). On the other hand, the current EU general limit value for natural methanol of 10 g methanol/ethanol (equivalent to 0.4% (v/v) methanol per 40% alcohol) offers a greater margin of safety.