Quantification Of Methanol Research Articles

A simple and low-cost method for determination of methanol in alcoholic solutions

Methanol poisoning can occur through consumption of methanol-containing alcohols, especially in areas where production, distribution, sale and consumption of alcohol is lawfully prohibited. Due to its toxic potency, determination of methanol in alcoholic solutions is important. The aim of the present study was to develop a rapid, simple and inexpensive method for quantification of methanol in alcoholic solutions that uses minimal equipment available in most laboratories. The method developed is based microdistillation and chromotropic acid, which can be conducted without sophisticated instruments or personal. The system consists of a micro-tube suspended in a falcon tube to function as a collector. Methanol is separated from wine by microdistillation at 90°C in water bath and converted to formaldehyde in the collector. The collector contains an acidic permanganate solution that converts methanol to formaldehyde. Formaldehyde was then quantified by use of chromotropic acid in concentrated sulfuric acid. Experimental variables were optimized by using central composite design (CCD). Method detection and quantification limits were 183mgL−1 and 584mgL−1, respectively. The percent relative standard deviation (RSD%) were between 6.4 and 7.9. Accuracies were between 89.6% and 92.4%. Concentrations of methanol in five alcoholic solutions were between 2.9×104 and 3.0×104, mg/L, v/v (ppm). Due to its simplicity and cost effectiveness, this method can be used for routine, real-time determination of methanol in alcoholic solutions.

Simultaneous Determination of Ethanol and Methanol in Wines Using FTIR and PLS Regression.

Accurate quantification of ethanol and methanol is essential for regulatory compliance and product quality assurance. Fourier Transform Infrared Spectroscopy (FTIR) offers rapid, non-destructive analysis with minimal sample preparation, making it a promising tool for wine analysis. In this exploratory study, the use of FTIR and PLS regression for the simultaneous quantification of ethanol and methanol in wine samples of 11 different Portuguese mono-varietal wines and different vintages deriving from the same winery in Lisbon was investigated. A model was developed, demonstrating the feasibility of FTIR and PLS regression for the simultaneous quantification of ethanol and methanol in wine samples through dedicated models; it showed good prediction capacity for ethanol determination but poorer performance for methanol quantification. The model could be reliable enough for quality control in wine production, but to improve its performance should be enhanced in the future with more samples from different origins, wine types, and a wider concentration range in the case of methanol.

Optics miniaturization strategy for demanding Raman spectroscopy applications

Raman spectroscopy provides non-destructive, label-free quantitative studies of chemical compositions at the microscale as used on NASA’s Perseverance rover on Mars. Such capabilities come at the cost of high requirements for instrumentation. Here we present a centimeter-scale miniaturization of a Raman spectrometer using cheap non-stabilized laser diodes, densely packed optics, and non-cooled small sensors. The performance is comparable with expensive bulky research-grade Raman systems. It has excellent sensitivity, low power consumption, perfect wavenumber, intensity calibration, and 7 cm−1 resolution within the 400–4000 cm−1 range using a built-in reference. High performance and versatility are demonstrated in use cases including quantification of methanol in beverages, in-vivo Raman measurements of human skin, fermentation monitoring, chemical Raman mapping at sub-micrometer resolution, quantitative SERS mapping of the anti-cancer drug methotrexate and in-vitro bacteria identification. We foresee that the miniaturization will allow realization of super-compact Raman spectrometers for integration in smartphones and medical devices, democratizing Raman technology.

Analysis of biodiesel and fatty acids using state-of-the-art methods from non-edible plants seed oil; Nicotiana tobaccum and Olea ferruginia

The long-term socioeconomic and environmental alternative to fossil fuels is biodiesel. Current biodiesel manufacturing research has developed competitive, sustainable methods. The study validates and explains biodiesel benefits while increasing output. Physicochemical characterizations, gas chromatography-mass spectrometry (GCMS), Fourier transform infrared (FTIR), elemental analysis (EA), inductively coupled plasma atomic emission (ICP-OES), and nuclear magnetic resonance (NMR) are studied. In this study, we discovered two inedible plant seeds, specifically Olea ferruginea (OF) and Nicotiana tobaccum (NT), which exhibited significant oil contents of 30–49% by weight; both seeds had minimal amounts of free fatty acids contents of 1.1% and 0.9%, and biodiesel yield 96.4–97.9% after an optimization process, i.e., methanol/ oil ratio (6:1), KOH concentration (0.32), temperature (65 °C), stirring rate (700 rpm), and time (60 mins). A comprehensive analysis was performed to investigate and contrast the physical, chemical, and compositional attributes of the FAMEs with those of mineral diesel. Gas chromatography determined biodiesel's chemical composition and detected various fatty acid methyl esters (FAMEs) i.e. palmitic (9.7–14.0), stearic (1.8–3.2), oleic (25.5–47.2), linoleic (8.5–32.2), α-Linolenic (3.6–1.1), arachidic (2.4–0.8), and gondoic acid was (48.5–0.5%), respectively. In novel biodiesel characterization, NMR spectroscopy defines and assigns sample chemical structures to identify and quantify unsaturated long-chain alkyl esters. NMR spectroscopic biodiesel methanol quantification is an alternative to official methods. 1H NMR revealed the molecular hydrogen nuclei. This study examines all biodiesel purity and transesterification performance parameters. Producing cost-effective and optimal biodiesel requires the intent of these properties. Inedible seeds can be cultivated in infertile terrain to improve biodiesel production and solve the energy dilemma.

Reduction of CO to Methanol with Recyclable Organic Hydrides.

The reaction steps for the selective conversion of a transition metal carbonyl complex to a hydroxymethyl complex that releases methanol upon irradiation with visible light have been successfully quantified in acetonitrile solution with dihydrobenzimidazole organic hydride reductants. Dihydrobenzimidazole reductants have been shown to be inactive toward H2 generation in the presence of a wide range of proton sources and have been regenerated electrochemically or photochemically. Specifically, the reaction of cis-[Ru(bpy)2(CO)2]2+ (bpy = 2,2'-bipyridine) with one equivalent of a dihydrobenzimidazole quantitatively yields a formyl complex, cis-[Ru(bpy)2(CO)(CHO)]+, and the corresponding benzimidazolium on a seconds time scale. Kinetic experiments revealed a first-order dependence on the benzimidazole hydride concentration and an unusually large kinetic isotope effect, inconsistent with direct hydride transfer and more likely to occur by an electron transfer-proton-coupled electron transfer (EΤ-PCET) or related mechanism. Further reduction/protonation of cis-[Ru(bpy)2(CO)(CHO)]+ with two equivalents of the organic hydride yields the hydroxymethyl complex cis-[Ru(bpy)2(CO)(CH2OH)]+. Visible light excitation of cis-[Ru(bpy)2(CO)(CH2OH)]+ in the presence of excess organic hydride was shown to yield free methanol. Identification and quantification of methanol as the sole CO reduction product was confirmed by 1H NMR spectroscopy and gas chromatography. The high selectivity and mild reaction conditions suggest a viable approach for methanol production from CO, and from CO2 through cascade catalysis, with renewable organic hydrides that bear similarities to Nature's NADPH/NADP+.

Analysis of Methanol Content in Different Varieties of Traditionally Fermented Alcohol Found in Chandannath Municipality of Jumla District, Nepal

Background: Alcohol poisoning associated with traditionally fermented alcoholic beverages have been reported in Nepal with the constituents of these beverages not being quantified usually. In traditionally fermented alcoholic beverages, methanol, due to its cheaper cost and similar physiochemical properties with ethanol, is adulterated most commonly and readily. The objective of the present study was to quantify four different varieties of traditionally fermented alcoholic beverages available in Chandannath, Jumla for methanol level.Methods: The present study is a cross-sectional study in which four different types of traditionally fermented alcoholic beverages were collected from Chandannath, Jumla and they were analyzed for methanol content. From Chandannath municipality, the ward number two was selected for collection of samples. Further, from this ward, four different households regularly involved in brewing local alcohol were also randomly selected. These households belonged to three different ethnic groups (Indo-Aryan, Tibeto-Burman and Newar) and these samples were chhyang (sample- 1), local raksi (sample- 2), nigar (sample- 3) and local apple cider (sample- 4). In air tight containers, the samples were sealed and transported to Zest laboratory, Bhaktapur, Nepal for quantification of methanol using Gas Chromatography.Results: The residents in half of these four households belonged to the Tibeto-Burman ethnic groups. Methanol was detected in two samples among the four analyzed beverages. These samples, sample- 2 and sample- 4, on quantification showed the concentrations of 10.050ppm and 13.721ppm of methanol respectively. Conclusion: Among four samples of locally brewed alcoholic beverages, methanol was detected in two samples, but at a concentration below the level that would be considered toxic. This finding emphasizes the importance of conducting larger-scale quantification of traditionally fermented alcohol to mitigate the various health risks associated with its potential toxicity, as these beverages are currently not being quantified.

PdxNiy/TiO2 Electrocatalysts for Converting Methane to Methanol in An Electrolytic Polymeric Reactor—Fuel Cell Type (PER-FC)

PdxNiy/TiO2 bimetallic electrocatalysts were used in fuel cell polymeric electrolyte reactors (PER-FC) to convert methane into methanol through the partial oxidation of methane promoted by the activation of water at room temperature. X-ray diffraction measurements showed the presence of Pd and Ni phases and TiO2 anatase phase. TEM images revealed mean particle sizes larger than those reported for PdNi materials supported, indicating that TiO2 promotes particle aggregation on its surface. Information on the surface structure of electrocatalysts obtained by Raman spectra indicated the presence or formation of NiO. The PER-FC tests showed the highest power density for the electrocatalyst with the lowest amount of nickel Pd80Ni20/TiO2 (0.58 mW cm−2). The quantification of methanol through the eluents collected from the reactor showed higher concentrations of methanol produced, revealing that the use of TiO2 as a support also increased the reaction rate.

Cellulose Degradation and Transformer Fault Detection by the Application of Integrated Analyses of Gases and Low Molecular Weight Alcohols Dissolved in Mineral Oil

This article presents a method for quantification of methanol and ethanol integrated in the same gas-chromatographic run with a quantification of gases dissolved in mineral oil, making it an integrated tool in transformer diagnostics. The results of aging experiments at 120 °C and 60 °C of Kraft paper, copper, barrier, and pressboard immersed in mineral oil, as well as the aging of thermal upgrade paper in mineral and natural ester oil at 140 °C are presented, in order to investigate correlations between different aging markers and to evaluate their partitioning between oil and cellulose at defined conditions. The results of partitioning experiments at 60 °C showed that re-absorption of methanol from oil to the cellulose materials is faster than the re-absorption of furans. This means that methanol is a paper-degradation marker that can be used in diagnostics over shorter equilibrium times and for the detection of developing faults at broader temperature ranges. Furthermore, a statistical overview of methanol concentration from a database and two transformer fault diagnostic cases are presented. Therefore, in addition to an analysis of gases dissolved in oil, the use of methanol and ethanol in transformer fault and failure investigations should be explored and verified through transformer fault investigations and postmortem analyses.

Quantification of Methanol, Ethanol, and Essential Oil Contents of Commonly Used Brands of Rosewater (Rosa Damascena) in Iran

Background: Rosa damascena Mill. (Rosaceae) is a relevant ornamental and medicinal flower, whose distillation is known as Golab (Rosewater) in Iran. Due to the nature of the distillation process, methanol and ethanol are likely to be formed in the final product. Therefore, due to their toxicity, along with their frequent prescription, this study aims to investigate the concentrations of essential oil, methanol, and ethanol in commonly used brands of Rosewater available in Tehran, Iran.
 Methods: Methanol and ethanol concentrations were determined by gas chromatography, using a Flame Ionized Detector.
 Results: The mean essence level in the tested samples was 204.1 ± 18.0 ppm, which was significantly higher (P < 0.001) than the Iranian standard level. The mean methanol and ethanol levels in the tested samples were 1.25 ± 0.70 ppm and 700.0 ± 100.0 ppm, respectively, which were significantly lower than the maximum residues levels.
 Conclusion: The mean essence level in the tested samples well coped with the Iranian standard level. Moreover, there is no health risk to methanol and ethanol through Rosewater consumption.

Processing Method for the Quantification of Methanol and Ethanol from Bioreactor Samples Using Gas Chromatography-Flame Ionization Detection.

Methanol, a simple polar solvent, has been widely identified as an attractive carbon source to produce chemicals and fuels in bioprocesses. Specifically, to achieve recombinant protein production from methylotrophic yeasts, such as Pichia pastoris, this organic solvent can be used as a sole carbon source for growth and maintenance as well as an inducer for protein expression. However, if methanol feeding is not controlled well in such a fermentation process, accumulation of the solvent in the growth media will have a detrimental effect on the cells. Hence, monitoring the levels of methanol in these fermentation processes is a crucial step to ensure a healthy culture and maximum protein production. There are various techniques elaborated in the literature for monitoring methanol in cell cultures, but often, they appear to be expensive methods that are less affordable for many laboratories. This is because, in addition to the sophisticated equipment that is required for the analysis, the complexity of the samples retrieved from the bioprocesses necessitates laborious processing steps often involving expensive tools. In this study, a fast, simple, and sensitive method is developed to process biological samples by using the salting-out-assisted liquid–liquid extraction technique to quantify the concentration of methanol and ethanol using gas chromatography. On comparing the combinations of widely available salts and solvents, it was noticed that salting out using potassium carbonate followed by the liquid–liquid extraction of the analyte using ethyl acetate showed the best recovery. Followed by this, a validation test for the developed method was performed, which resulted in good peak resolution, linearity, and limit of detection for the quantitation of methanol and ethanol. By further assessing the tested combination, it was confirmed that its application could be extended to other matrices. Such an approach facilitates the possibility to monitor and control the methanol levels in fermentation and aids in bioprocess optimization.

Development of analytical methodologies for the quality control of liquors using nearby infrared spectroscopy and multivariate analysis

The application of NIR near-infrared spectroscopy and multivariate analysis as a rapid analysis technique in the quantification of the content of methanol in commercially distributed liqueurs (Aguardiente), to identify if these liqueurs exceed the methanol limits established in the standard. AOAC 972.11 (100 mg / dm3) (AOAC 972.11, 1973). For this, in a first stage, the application of a design of ternary mixtures methanol-ethanol-water (MDOE) was carried out in order to reduce correlation effects between the variables, in addition to achieving multivariate models that include variability important by expanding the calibration range that act under process conditions and in commercialization sites. The second stage was associated with the recording of the NIR spectra of the prepared samples, to obtain a data matrix, from which the multivariate models are developed using different algorithms. The results obtained showed that it is possible to develop a rapid analysis method for the quantification of methanol in Aguardiente samples, using NIR spectroscopy and the multivariate models constructed, in which a Mean Square Prediction Error (RMSEP) of 0.7766 was obtained. % and correlation coefficient (R2) of 0.9553.

1H NMR spectrometry for methanol quantification in apple wines and ciders as optimised by comparison to SIDA-HS-GC-MS

Methanol, a hepato- and neurotoxic compound, is present in apple-based beverages as a by-product of the enzymatic degradation of pectin. Stable isotope dilution assay (SIDA) employing gas chromatography-mass spectrometry (GC–MS) is the state-of-the-art method for methanol determination in beverages. Despite higher initial investment costs, quantitative 1H NMR spectroscopy (qNMR) is a simpler and faster analytical technique to quantify numerous analytes in liquid foods. Beyond targeted analyses, qNMR spectral fingerprints in the product might be used for non-targeted analytical goals, such as adulteration and contamination detections. Here, an existing 1H-qNMR method used for wine profiling was optimised for methanol quantification in apple-based products, including cross-validation against a SIDA-HS-GC–MS method and reference values from interlaboratory trials. The optimisation involved a pivotally important estimation of a correction factor by an external calibration approach, making qNMR results comparable to SIDA-HS-GC–MS. The optimised qNMR method is suggested to be an alternative for methanol quantification in beverages.

Novel Electrochemical Sensor Based on Cu(II) for Detecting Methanol in Alkaline Media

Metal-organic frameworks are novel materials with specific pore-size that presents unlimited applications in electrocatalysis and electro-analytical chemistry. The presence of metallic ions in the MOF structure offers a redox active material with electrocatalytical properties in alkaline media towards diverse organic compounds and heavy metals. This property is extensively used to replace enzymes in electrochemical sensors for detecting glucose and other molecules. In this work, we present the synthesis, characterization and application of Cu-BTC MOF as redox active material in a carbon paste electrode (CPE) for methanol electrochemical sensing in alkaline media. The obtained electrode was evaluated for the selective quantification of methanol in ethanol solutions by using diferential pulse voltammetry. The analysis of methanol with the modified electrode presented a LOD, LOQ and sensitivity of 0.04438 mM, 0.1479 mM and 52.74 ± 1.3 μA mM-1 respectively, and a electro-active area of 0.01723 cm2. Our analytical parameters are superior compared with those presented by using enzyme-based electrodes. These results demonstrate the potential use of Cu-BTC@EPC sensors in detecting MeOH at low concentratios, even in presence of ethanol. Figure 1

Cu(II) Metal-Organic Framework Based Electrochemical Sensor for Methanol Quantification in Alkaline Media

Metal-Organic frameworks are novel materials with specific pore-size that presents unlimited applications in electrocatalysis and electro-analytical chemistry. The presence of metallic ions in the MOF structure offers a redox active material with electrocatalytical properties in alkaline media towards diverse organic compounds and heavy metals. This property is extensively used to replace enzymes in electrochemical sensors for detecting glucose and other molecules. In this work, we present the synthesis, characterization and application of Cu-BTC MOF as redox active material in a carbon paste electrode (CPE) for methanol electrochemical sensing in alkaline media. The obtained electrode was evaluated for the selective quantification of methanol in ethanol solutions by using diferential pulse voltammetry. The analysis of methanol with the modified electrode presented a LOD, LOQ and sensitivity of 0.04438 mM, 0.1479 mM and 52.74 ± 1.3 μA mM-1 respectively, and a electro-active area of 0.01723 cm2. Our analytical parameters are superior compared with those presented by using enzyme-based electrodes. These results demonstrate the potential use of Cu-BTC@EPC sensors in detecting MeOH at low concentratios, even in presence of ethanol. Figure 1

Synthesis of Ni2P/CdS and Pt/TiO2 nanocomposite for photoreduction of CO2 into methanol

It is a great challenge to convert thermochemically stable CO2 into value-added products such as CH4, CH3OH, CO via utilizing solar energy. It is also a difficult task to develop an efficient catalyst for the reduction of CO2. We have designed and synthesized noble metal-free photocatalytic nanostructure Ni2P/CdS and Pt/TiO2 for conversion of CO2 to methanol in the presence of sacrificial donor triethylamine (TEA) and hydrogen peroxide. The synthesised catalysts physicochemical properties were studied by using several spectroscopic techniques like; XRD, UV-DRS, XPS, TEM, SEM and PL. Quantification of methanol by GC–MS showed encouraging results of 1424.8 and 2843 μmol g−1 of catalyst for Pt/TiO2 and 5 wt% Ni2P/CdS composites, respectively. Thus, Ni2P/CdS is a promising catalyst with higher productivity and significant selectivity than in-vogue catalysts.

SIMULTANEOUS QUANTITATIVE 1H NMR ANALYSIS OF METHANOL, ETHANOL AND THEIR METABOLIC PRODUCTS IN HUMAN PLASMA: EARLY DIANOSIS AND MONITORING DURING TREATMENT OF ACUTE METHANOL POISONING IN VIETNAM

The 1H-NMR method for simultaneous quantification of methanol, ethanol and their metabolic products (formic acid and acetic acid) in human plasma was established. The effect of protein in plasma sample was removed by 25% trichloroacetic acid (TCA) with the ratio of TCA and plasma sample at 1/5 (v/v). The small amount of D2O (estimated 1/10 v/v) was chosen due to the effect of water signal was eliminated by using the advance water suppression with NOESY pulse sequence. The different analytical parameters such as linearity, precision, accuracy, and specificity, instrument detection limit (IDL) and instrument quantification limit (IQL) were validated. The instrument detection limit of four compounds in blank plasma varied from 0.68 (for methanol) to 2.88 mg/L (for formic acids). The average recoveries of concentration in dynamic ranges were found to be 96 to105%. The good linearity between concentration calculated by integrated signal and measured obtained by calibration curves confirmed that concentration of analytes in plasma can be directly determined from the 1H-NMR signal. The proposed method has been successfully applied for direct determination of five compounds in 9 patient’s plasma samples with the satisfactory results compared to GC/FID method. The analytical procedure can be useful for diagnosis and evaluation of treatment of methanol poisoning in Vietnamese hospitals.

Detecting methanol in hand sanitizers

SummaryThe coronavirus disease 2019 (COVID-19) pandemic has increased dramatically the demand for hand sanitizers. A major concern is methanol adulteration that caused more than 700 fatalities in Iran and U.S.A. (since February 2020). In response, the U.S. Food and Drug Administration has restricted the methanol content in sanitizers to 0.063 vol% and blacklisted 212 products (as of November 20, 2020). Here, we present a low-cost, handheld, and smartphone-assisted device that detects methanol selectively in sanitizers between 0.01 and 100 vol% within two minutes. It features a nanoporous polymer column that separates methanol selectively from confounders by adsorption. A chemoresistive gas sensor detects the methanol. When tested on commercial sanitizers (total 76 samples), methanol was quantified in excellent (R2 = 0.99) agreement to “gold standard” gas chromatography. Importantly, methanol quantification was hardly interfered by sanitizer composition and viscosity. This device meets an urgent need for on-site methanol screening by authorities, health professionals, and even laymen.

Detection of Electrooxidation Products in Microfluidic Devices Using Raman Spectroscopy

Microfluidic devices combined with Raman Spectroscopy have great promise for in-situ and online detection of reaction processes with only a small volume of liquid required. This advanced method allows for flexible manipulation of fluids, micro/nano-particles, and biological samples1. Lab-on-a-chip applications are often used for chemical analysis, but Raman microscopy has also been used to monitor reactions within microreactors. The combination of the controlled mass transport in microfluidics with detection of soluble intermediate and product species by Raman offers the possibility of mechanistic kinetic studies of electrocatalytic reactions. We here show the feasibility of this method for studying electrocatalysis of oxidation of alcohols.Two types of microfluidic flow devices were fabricated, which used glass slides and printed circuit boards (PCBs) as substrates, respectively. For glass-slide-based microfluidic devices, Raman spectra were used to monitor methanol oxidation catalyzed by a Pt mesh electrode, and calibration with known solutions enabled quantification of methanol and formate concentrations. A comparative study of catalytic oxidations of glycerol, ethanol, ethylene glycol and 1-propanol using electrodeposited Ni on carbon paper showed that under strong alkaline conditions, glycerol and ethylene glycol principally gave formate and carbonate products, while ethanol and 1-propanol did not give formate. Acetate was found to be the major oxidation product of ethanol, with only a small amount of carbonate. For PCB-based microfluidic substrates, electroplated Ni on Cu pads gave planar working electrodes, which were used to catalyze the oxidation of glycerol. On-board PdH reference electrodes were incorporated2.1. A.F. Chrimes, K. Khoshmanesh, P.R. Stoddart, A. Mitchell, K. Kalantar-zadeh, Microfluidics and Raman microscopy: current applications and future challenges, Chem. Soc. Rev., 42, 5880 (2013).2. E.V. Fanavoll, D.A. Harrington, S. Sunde, G. Singh and F. Seland, A Microfluidic Electrochemical Cell with Integrated PdH Reference Electrode for High Current Experiments, Electrochim. Acta., 225 , 69 (2017).Acknowledgement: This research was conducted as part of the Engineered Nickel Catalysts for Electrochemical Clean Energy project administered from Queen’s University and supported by Grant No. RGPNM 477963-2015 under the Natural Sciences and Engineering Research Council of Canada (NSERC) Discovery Frontiers Program. Figure 1

Highly Selective Wearable Smartsensors for Vapor/Liquid Amphibious Methanol Monitoring.

A wearable screen-printed electrochemical smartsensor with excellent selectivity for methanol quantification has been developed. This smartsensor consists of a printable sensing system modified with platinum (Pt) confined in a reduced graphene oxide (rGO) matrix, as well as a compact electronic interface for data collection. The real-time electrochemical signal from methanol could be remotely detected and transmitted to a smartphone by blue tooth. It performs good environmental adaptability of vapor/liquid amphibious behaviors. Owing to the uniform distribution of Pt loading on the rGO nanosheets, this sensor demonstrates high selectivity, sensitivity, stability, and recoverability both in vapor and liquid during temperature or humidity diversification, compared with other resistance-based sensors. It also achieves good bending and stretching performance, and it could be a possible candidate device for the quantification of methanol in different environments.

Determination of methanol residues in crude glycerol for animal feed by gas chromatography

ABSTRACT: Crude glycerol is a major by-product of biodiesel production and is an economical additive feed for ruminants. However, residual methanol in crude glycerol can be harmful to animal health. Several methods exist for quantifying methanol residues in biodiesel, yet few have been described that identify the methanol level in crude glycerol. We propose a method for determining the methanol level in crude glycerol destined for animal feed. Crude glycerol was extracted from the headspace and quantified by gas chromatography using a flame ionization detector (GC-FID). The method was linear up to 0.5 % of methanol. The limits of detection (LOD) and quantification (LOQ) were 0.015 and 0.031 %, respectively. No significant matrix effects were observed. Precision was 2 % at the 0.05 and 0.5 % levels. The average percentage of recovery was 90 %. Three analyzed samples of crude glycerol had methanol residues of 0.027-7.802 %. Furthermore, this methanol quantification method may be externally or internally calibrated using a GC manual injector. A reduction of at least 20 % in running time was obtained with good resolution between the peaks. Thus, this method can be applied to determine the methanol level in crude glycerol according to the upper limits for animal feed (5,000 ppm) and for human consumption (150 ppm). Finally, this method is useful for the quality control of crude glycerol intended for use in animal feed, enabling the alternative use of this by-product to add value to the biodiesel production chain.