Simultaneous Determination Of Methanol Research Articles

Simultaneous determination of methanol, ethanol, and formic acid in human serum by HSGC-MS: Method development, validation, and application

The concurrent assessment of methanol, ethanol, and formic acid is imperative for accurate clinical toxicology diagnosis in cases of methanol poisoning. Here, we reported a very simple and reliable headspace gas chromatography coupled with mass spectrometry (HSGC-MS) method for simultaneous quantitative determination of methanol, ethanol and formic acid in blood samples. The derivatization variables for formic acid were optimized. The method exhibits high sensitivity, good selectivity and effective separation factor for methanol (6.51 min), ethanol (8.29 min), and formic acid (11.41 min). The method demonstrates excellent reproducibility and accuracy. The limit of detection (LOD) and the limit of quantification (LOQ) were determined to be 3.14–5.83 μg/mL and 10.47–19.34 μg/mL, respectively. Finally, this method was successfully used for measuring the levels of methanol, ethanol, and formic acid in the serum of patients involved in actual methanol poisoning incidents.

Determination of ethanol, isopropyl alcohol and methanol in alcohol-based hand sanitiser to ensure product quality, safety and efficacy

The Coronavirus Disease-2019 (COVID-19) outbreak is an unprecedented global pandemic, sparking grave public health emergencies. One of the measures to reduce COVID-19 transmissions recommended by the World Health Organization is hand hygiene, i.e., washing hands with soap and water or disinfecting them using an alcohol-based hand sanitiser (ABHS). Unfortunately, competing ABHSs with unknown quality, safety, and efficacy thrived, posing yet another risk to consumers. This study aims to develop, optimise, and validate a gas chromatography-mass spectrometry (GC–MS)-based analytical method to simultaneously identify and quantify ethanol or isopropyl alcohol as the active ingredient in ABHS, with simultaneous determination of methanol as an impurity. The GC–MS was operated in Electron Ionisation mode, and Selected Ion Monitoring was chosen as the data acquisition method for quantitation. The analytical method was validated for liquid and gel ABHSs, covering the specificity, linearity and range, accuracy, and precisions, including the limit of detection and the limit of quantitation. The specificity of each target analyte was established using the optimised chromatographic separation with unique quantifier and qualifier ions. The linearity was ascertained with a coefficient of determination (r2) of > 0.9994 over the corresponding specification range. Respectively, the accuracy and precisions were satisfactory within 98.99 to 101.09% and < 3.04% of the relative standard deviation. The method was successfully applied to 69 ABHS samples, where 14 contained insufficient amounts of the active ingredient. Alarmingly, four samples comprised a high amount of methanol ranging from 5.3 to 19.4% with respect to the active alcohol percentage, which may pose significant short- and long-term health issues, leading to life-threatening crises for consumers. The method established would benefit in protecting the public against the potential harm due to substandard or unsafe ABHS products, primarily due to the presence of hazardous impurities such as methanol.

Simultaneous measurement of formic acid, methanol and ethanol in vitreous and blood samples of postmortem by headspace GC-FID

BackgroundFormic acid (formate) is the main reason for toxicity and death through methanol poisoning. The simultaneous determination of methanol, ethanol, and formate in the body can help to discover the cause of death and is useful in the diagnosis of acute methanol poisoning. The measurement of formate is not yet available in Iran. With regard to the increasing rate of methanol poisoning and its related mortality in Iran, as well as the main role of formate in methanol poisoning, this study was designed to set up an analytical method for the concurrent determination of ethanol, methanol, and formate.MethodsFollowing the modification of a previously developed gas chromatography method, vitreous and blood samples of 43 postmortem cases with a history of methanol intoxication were collected over a period of 2 years at the Legal Medicine Organization of Mashhad. Thereafter, ethanol, methanol, and formate concentrations were measured by headspace GC/FID. Formate esterification was performed by the methylation of formate with sulfuric acid and methanol. In order to confirm the esterification method for the production of methyl formate, we used gas chromatography with a mass detector (GC/MS) because of its higher sensitivity and accuracy. Furthermore, the correlations between formate and methanol concentrations in blood and vitreous samples, and between formate and methanol were investigated.ResultsA significant relationship was found only between methanol concentrations in blood and vitreous samples (P < 0.03).ConclusionsIn postmortems, with the passage of time since alcohol ingestion, the measurement of only methanol concentration cannot determine the degree of toxicity or the cause of death. Therefore, using the present analytical method and measurement of formic acid, we can estimate the degree of toxicity and cause of death.

Simultaneous Determination of Methanol and Ethanol Content in Traditional Chinese Jujube Brandy

Simultaneous Determination of Methanol and Ethanol Content in Traditional Chinese Jujube Brandy

Analysis of methanol and ethanol in virgin olive oil

This work provides a short and easy protocol that allows the analysis of both methanol and ethanol in the static headspace of olive oil. The procedure avoids any kind of sample pre-treatment beyond that of heating the oil to allow a maximum volatile concentration in the headspace of the vials. The method's LOD is 0.55mgkg−1 and its LOQ is 0.59mgkg−1. Advantages of this method are:•Simultaneous determination of methanol and ethanol (the pre-existing Spanish specification UNE-EN 14110 only analyses methanol).•No need of equipment modifications (standard split injectors work perfectly). Use of a highly polar capillary GC column, leading in most cases to chromatograms in which only three dominant peaks are present – methanol, ethanol, and propanol (that is extremely positive for easy interpretation of results).•Use of an internal standard (1-propanol) to determine the concentration of the analytes, reducing the presence of error sources.

Simultaneous determination of methanol, acetaldehyde, acetone, and ethanol in human blood by gas chromatography with flame ionization detection

Methanol, acetaldehyde, acetone, and ethanol, which are commonly used as biomarkers of several diseases, in acute intoxications, and forensic settings, can be detected and quantified in biological fluids. Gas chromatography (GC)-mass spectrometry techniques are complex, require highly trained personnel and expensive materials. Gas chromatographic determinations of ethanol, methanol, and acetone have been reported in one study with suboptimal accuracy. Our objective was to improve the assessment of these compounds in human blood using GC with flame ionization detection. An amount of 50 µl of blood was diluted with 300 µl of sterile water, 40 µl of 10% sodium tungstate, and 20 µl of 1% sulphuric acid. After centrifugation, 1 µl of the supernatant was injected into the gas chromatograph. We used a dimethylpolysiloxane capillary column of 30 m × 0.25 mm × 0.25 µm. We observed linear correlations from 7.5 to 240 mg/l for methanol, acetaldehyde, and acetone and from 75 to 2400 mg/l for ethanol. Precision at concentrations 15, 60, and 120 mg/l for methanol, acetaldehyde, and acetone and 150, 600, and 1200 mg/ml for ethanol were 0.8-6.9%. Ranges of accuracy were 94.7-98.9% for methanol, 91.2-97.4% for acetaldehyde, 96.1-98.7% for acetone, and 105.5-111.6% for ethanol. Limits of detection were 0.80 mg/l for methanol, 0.61 mg/l for acetaldehyde, 0.58 mg/l for acetone, and 0.53 mg/l for ethanol. This method is suitable for routine clinical and forensic practices.

Simultaneous gas chromatographic determination of methanol and free glycerol in biodiesel

The methanol and free glycerol content of vegetable oil methyl esters used as diesel fuel (biodiesel) is very important in describing the quality of this fuel and is therefore limited by specifications. A previously described GLC method for the determination of free glycerol in biodiesel has been further developed and also allows the simultaneous determination of methanol. Sample preparation includes dissolving in dimethylformamide, silylation with bis-trimethylsilyltrifluoracetamide (BSTFA) and separation on a methylsilicone fluid, coated-capillary column using either FID or MS-detection. Ethanol and 1,4-butanediol were used as internal standards. Both detection systems show sufficient sensitivity for concentrations relevant to biodiesel samples. The recovery was tested using a RME-sample containing known amounts of methanol and glycerol.