Quantitative analysis of methanol in blood, urine, vitreous humor, and cerebrospinal fluid by using gas chromatography-head space in two suspected cases of methanol poisoning

Methanol is a toxic alcohol and can be encountered in clinical and forensic cases. Methanol toxicity is primarily related to its metabolic products-formaldehyde and formic acid, which can cause metabolic acidosis, blindness, CNS disorders, coma, or even death. Quantitative determination and elucidation of methanol levels is crucial in clinical and forensic toxicology. Gas chromatography-headspace (GC-HS) can be used to determine methanol concentration in various biological fluids. This study reports two cases of suspected methanol poisoning. Blood, urine, vitreous humor, and cerebrospinal fluid (CSF) samples were taken for toxicological analysis during post-mortem examination. The samples were run in GC-HS for analysis of ethanol and methanol. The analysis only required 1 ml of sample and the addition of internal standard (IS). Total runtime of analysis was achieved within 20 min. Methanol was successfully detected in blood, urine, vitreous humor, and CSF using GC-HS. GC-HS is efficient for the determination of methanol concentrations, owing to its high specificity, reliability sensitivity, and reproducibility. This study also emphasizes the collection and analysis of multiple specimens, including those that are more resistant to post-mortem changes, so that they can be tested in cases where a blood sample is not readily obtainable due to alterations, putrefaction, etc. The use of an alternative specimen to the blood is of great relevance for forensic purposes.