Methanol Levels Research Articles

Survey On Methanol Poisoning Epidemic in Rafsanjan City in Year 2013

Background: Examination and early detection of the methanol toxicity epidemic are very important, so identification and initiation of appropriate therapy can significantly reduce morbidity and mortality. Therefore, this study was aimed to investigation methanol poisoning epidemic in Rafsanjan city.Methods: This case series study was conducted in 252 patients with methanol poisoning in 2013 in the Ali-ibn-Abi-Talib hospital of Rafsanjan. Data were through interviews and records that were collected at hospital admission. Due to the large number of patients and the possible lack of ability of rapid measurement of serum levels of methanol and need of rapid intervention, treatment to reduce any further complications, early diagnosis and treatment were carried out by clinical history and interpretation of arterial blood gas test results. Data record on provided checklists and then analyzed using SPSS version 19.Results: The mean pH was 0.13±7.27. The most frequent clinical features were visual disturbances (39.7%), dyspnea (1.2%), and gastrointestinal symptoms (7.1%). There was a trend towards decreasing PCO2 with decreasing pH amongst the patients surviving. The opposite trend was demonstrated in the dying; the difference was highly significant by linear regression analyses (P< 0.001).Conclusions: Methanol poisoning still has a high morbidity and mortality, mainly because of late diagnosis and treatment. Respiratory arrest, coma and severe metabolic acidosis upon admission were strong predictors of poor outcome. Early admission and ability of respiratory compensation of metabolic acidosis were associated with survival.

Influence of methanol when used as a water-miscible carrier of pharmaceuticals in TiO2 photocatalytic degradation experiments

Research on the use of titanium dioxide (TiO2) for water treatment has expanded to include the degradation of pharmaceuticals and personal care products (PPCPs). PPCPs are typically introduced in aqueous solutions during TiO2 photocatalysis experiments using a water-miscible carrier solvent (e.g. methanol) to improve their solubility; however, carrier solvents may be detrimental to photocatalysis due to their scavenging effect. Although it is advisable to maintain the solvent at low concentrations, the influence of elevated concentrations of methanol or other solvents on photocatalysis has not been carefully explored. In this study, we examined the impacts of different methanol concentrations (0–0.2% v/v) on photocatalysis using P25 (commercial TiO2) and TiO2 nanomaterial synthesized via thermal and chemical oxidation (TCO). Scavenging of hydroxyl radicals by methanol was evident for both P25 and TCO but the effect was more prominent on TCO. Also, the photodegradation of some compounds using P25 were enhanced at low levels of methanol. Overall, this study highlights that trace amounts of methanol used as a carrier solvent can affect photocatalysis, especially in TiO2 nanomaterials with low reactivity. This should be considered carefully in future experiments so that the results are not biased by the introduction of carrier solvents.

Chemical compositions of traditional alcoholic beverages and consumers characteristics, Ethiopia

Commercially available home brewed alcoholic beverages of Areki and Tej from Addis Ababa and other regional cities of Ethiopia were analysed for alcohol concentration, methanol level and other additives. Surveys were also carried out on the rate of alcoholism and the socio-demographic characteristics of the consumers. The chemical properties of the sampled beverages showed that home distilled Areki and fermented Tej drinks can pose health threats due to their high alcoholic strength and undesirable additives. Methanol concentration was found significantly below the highest limit to causing harm to human health. Close to a third of the observed Tej and Areki users have exhibited symptoms of alcoholism. Factors related to gender and reasons for drinking were significantly associated with alcohol abuse. The introduction of community-based intervention to reduce the rate of alcoholism in Addis Ababa is strongly suggested. Commercial vending houses should be subjected to acceptable regulations in their mode of production and delivery mechanisms. Applicable strategies for effective management and supervision of traditional alcohol consumption and to reduce alcoholism and risks of health menace are recommended. Further studies on other health influencing substrates deserve supporting. Key words: Homemade alcohols, Tej and Areki, community survey, alcoholism, chemical compositions, Ethiopia.

Fomepizole単独療法で治療を完遂したメタノール中毒の1例(Fomepizole alone therapy for a case of methanol intoxication)

要旨症例は21歳の男性，自殺目的に燃料用アルコール（メタノール76.6%含有）を飲用し，当院に救急搬送された。来院時，症状が軽微かつ検査値異常を認めないために緊急血液浄化療法の適応はないと判断し，fomepizoleの投与を行い入院となった。翌日，予測血中メタノール濃度が340mg/dLと異常高値であったが，その他の異常を認めなかったためにfomepizoleの投与のみを継続した。最終的に16日間，合計30回，本薬剤の投与を行い，合併症なく退院した。2015年1月よりアルコール脱水素酵素阻害薬であるfomepizoleのメタノール中毒・エチレングリコール中毒に対する使用が本邦でも保険適応となり，アルコール類中毒に対する標準的治療は大きく変化した。本薬剤のメタノール中毒への有効性は海外で広く認知されているが，従来用いられてきたエタノールによる解毒法と比較して医療費が非常に高額となり，その使用方法には依然として議論がある。今回我々は，fomepizole単独療法と血液浄化併用療法との比較を，患者管理の視点に加え，医療費の面からも検討した。その結果，個々の症例の血中メタノール濃度や患者状態，予測される治療期間に応じて2つの治療方法を使い分ける必要があり，血液浄化療法導入となる血中メタノール濃度の基準は50mg/dL程度であると考えられた。

Delayed response to cold stress is characterized by successive metabolic shifts culminating in apple fruit peel necrosis

BackgroundSuperficial scald is a physiological disorder of apple fruit characterized by sunken, necrotic lesions appearing after prolonged cold storage, although initial injury occurs much earlier in the storage period.To determine the degree to which the transition to cell death is an active process and specific metabolism involved, untargeted metabolic and transcriptomic profiling was used to follow metabolism of peel tissue over 180 d of cold storage.ResultsThe metabolome and transcriptome of peel destined to develop scald began to diverge from peel where scald was controlled using antioxidant (diphenylamine; DPA) or rendered insensitive to ethylene using 1-methylcyclopropene (1-MCP) beginning between 30 and 60 days of storage. Overall metabolic and transcriptomic shifts, representing multiple pathways and processes, occurred alongside α-farnesene oxidation and, later, methanol production alongside symptom development.ConclusionsResults indicate this form of peel necrosis is a product of an active metabolic transition involving multiple pathways triggered by chilling temperatures at cold storage inception rather than physical injury. Among multiple other pathways, enhanced methanol and methyl ester levels alongside upregulated pectin methylesterases are unique to peel that is developing scald symptoms similar to injury resulting from mechanical stress and herbivory in other plants.

Process development for production and purification of the Schistosoma mansoni Sm14 antigen

The trematode Schistosoma mansoni Sm14 antigen was expressed in the yeast Pichia pastoris and secreted into the culture medium at yields of approximately 250 mg L−1. Sm14 belongs to a family of fatty-acid binding proteins and appears to play an important role in uptake, transport, and compartmentalization of lipids in S. mansoni and it is a potential vaccine candidate in both humans and domesticated animals. The Sm14 gene was codon-optimized for expression in P. pastoris, and placed under transcription of the strong methanol inducible AOX1 promoter. Mut+ transformants were selected and used in fed-batch cultivation using a 2.5L fermenter equipped with an on-line methanol control system in order to maintain constant methanol levels during induction. Optimal conditions for the expression of Sm14 by P. pastoris were found to be: dissolved oxygen at 40%, temperature of 25 °C, pH 5.0, and a constant methanol concentration of 1 gL-1. Our results show that a correctly processed Sm14 was secreted into the culture medium at levels of approximately 250 mg L−1. Sm14 from clarified culture medium was purified using a two-step procedure: anion-exchange chromatography followed by hydrophobic interaction chromatography, resulting in >95% purity with a final yield of 40% from the starting cell culture medium. This product has been tested in preliminary clinical trials and shown to elicit an antibody response with no adverse reactions.

CARACTERIZAÇÃO, USO E LIMITAÇÕES DA GLICERINA NA ALIMENTAÇÃO DE SUÍNOS: REVISÃO

Glicerina é um líquido adocicado, higroscópico, inodoro, viscoso, energético, contendo variáveis níveis de glicerol, sendo utilizado como nutriente glicogênico ou lipogênico, dependendo da condição energética do animal. O glicerol ou 1,2,3-propanotriol é pertencente a função álcool, com três hidroxilas, de fórmula molecular C3H8O3. Em suínos, altos níveis de inclusão de glicerina podem proporcionar baixo conteúdo energético, pois o sistema enzimático da glicerol quinase torna-se saturado na conversão do glicerol para glicerol-3-fosfato, sendo o excesso excretado pela urina. A matéria-prima é um dos fatores que mais influenciam na composição da glicerina, podendo ser produzida a partir de óleo de soja, sebo bovino, gordura amarela e gordura de aves. Os componentes com maior participação na composição são glicerol, água e lipídios, contudo as limitações de seu uso na alimentação animal estão ligadas aos níveis residuais de sódio, potássio, metanol e umidade. Os níveis de glicerina bruta mais indicados para a viabilidade técnica e econômica estão em torno de 10%, sendo que acima de 15% compromete o desempenho e a viabilidade econômica. Por possuir características favoráveis e teores de energia em torno de 3.579 kcal/kg de energia metabolizável, a glicerina pode ser utilizada como ingrediente energético em rações para suínos.

Chemometric evaluation of the combined effect of temperature, pressure, and co-solvent fractions on the chiral separation of basic pharmaceuticals using actual vs set operational conditions

The need to determine the actual operational conditions, instead of merely using the set operational conditions, was investigated for in packed supercritical fluid chromatography (SFC) by design of experiments (DoE) using a most important type of compounds, pharmaceutical basics, as models. The actual values of temperature, pressure, and methanol levels were recorded and calculated from external sensors, while the responses in the DoE were the retention factors and selectivity. A Kromasil CelluCoat column was used as the stationary phase, carbon dioxide containing varying methanol contents as the mobile phase, and the six racemates of alprenolol, atenolol, metoprolol, propranolol, clenbuterol, and mianserin were selected as model solutes. For the retention modeling, the most important term was the methanol fraction followed by the temperature and pressure. Significant differences (p<0.05) between most of the coefficients in the retention models were observed when comparing models from set and actual conditions. The selectivity was much less affected by operational changes, and therefore was not severely affected by difference between set and actual conditions. The temperature differences were usually small, maximum ±1.4°C, whereas the pressure differences were larger, typically approximately +10.5bar. The set and actual fractions of methanol also differed, usually by ±0.4 percentage points. A cautious conclusion is that the primary reason for the discrepancy between the models is a mismatch between the set and actual methanol fractions. This mismatch is more serious in retention models at low methanol fractions. The study demonstrates that the actual conditions should almost always be preferred.

Can duration of hemodialysis be estimated based on the on-arrival laboratory tests and clinical manifestations in methanol-poisoned patients?

We aimed to evaluate the efficacy of Lachance formula and more readily available clinical or laboratory factors (other than serum methanol level) in prediction of the needed time for hemodialysis in methanol-poisoned patients. In a retrospective study, all methanol-poisoned patients referred to us between March 2008 and March 2016 were enrolled. The patients' demographic characteristics, on-arrival vital signs, signs/symptoms, and laboratory tests were evaluated for factors that could prognosticate the dialysis duration. Of 72 patients enrolled, 54 underwent hemodialysis once (group 1) and 18 needed more than one session of hemodialysis (group 2). All were treated by ethanol, bicarbonate, and leucovorin. Lachance formula overestimated the patients in higher methanol levels and underestimated them in lower methanol levels. It properly predicted the needed time for hemodialysis when the methanol level was between 15 and 25mg/dL. Groups 1 and 2 were different in terms of their ingested alcohol dose (P=0.001), creatinine (P=0.02), dyspnea on presentation (P=0.002), and the place they had been dialyzed (P=0.013). Dialysis duration significantly correlated with dyspnea on presentation (P=0.028) and ingested alcohol dose (P=0.02). After performance of logistic regression analysis, only creatinine was statistically significantly different between the two groups (P=0.02). Median creatinine levels were 1.3 [1, 6] (0.8-2.7) and 1.4 [1.35, 2.1] (0.8-6.5) in the patients who were dialyzed once and twice, respectively. As a conclusion, creatinine is possibly a readily available test that can predict the appropriate time needed for hemodialysis in methanol-poisoned patients.

Studies of Boil Treatment on Methanol Control and Pilot Factory Test of Jujube Brandy

Abstract The development of jujube brandy is restricted severely by excessive methanol production. Three methods to reduce methanol production were compared: fermentation material, boil and storage container. Boil treatment showed the best result, reducing methanol from 1.77 to 0.21 g/L, which was chosen for further analysis for comparing aroma compounds. Boil treatment increased ester, acids, and hydrocarbons; decreased alcohols, aldoketones, and terpenoids. The largest changes were seen in esters, hydrocarbons, and terpenoids. A pilot test of Boil treatment was performed. Results from the pilot test were consistent with laboratory results, with a significant decrease in methanol from 7.69 to 0.54 g/L. During the pilot test, methanol levels were measured in each fermentation layer and no significant difference was seen. Methanol levels were also measured in different distillation times. The foreshot had the highest concentration of methanol and the feint had the lowest concentration of methanol. Therefore, boil treatment combined with appropriate distillation will effectively solve the problem of excessive methanol production.

Methanol in wine

This paper examines the origins of methanol in grape wine and the quantities typically found in it, as well as in other foods such as unpasteurised fruit juices. The toxicology of methanol and the associated regulatory limits established by competent authorities in various parts of the world are also considered. It is concluded that such limits are not driven by public health considerations and thus authorities are requested to consider the need for methanol analyses to be performed and reported on certificates of analysis as a condition of market entry for wine. Where methanol limits are still deemed to be necessary to achieve policy objectives, authorities are encouraged to establish them in the light of the levels of methanol typically found in grape wines produced by the full array of internationally permitted winemaking practices, and to consider harmonising their limits with those that have already been established by other governments or recommended by appropriate intergovernmental organisations.

THE ROLE OF PULSE STEROID THERAPY IN CASES OF METHANOL INDUCED OCULAR TOXICITY

Methanol poisoning and toxic optic neuropathy is still seen in many parts of the developing world. In Egypt, it is one of the recorded cases in poison control centers especially among members of lower socioeconomic class. Particular vulnerability of the optic nerve and the retina; to toxic effect of methanol is known. The principle of steroid use is based on the postulation that blurring of vision in methanol poisoning could be following acute optic neuritis due to retrolaminar demyelination. The benefit has been proposed to be due to anti-inflammatory and immunosuppressant effect of steroids. Some authors objected to the effectiveness of this therapy. Aim of this study was to clarify the role of pulse steroid therapy in management of the victims of acute methanol poisoning who complained from visual defecit. Also, estimation of some prognostic factors for survival and final visual outcome was targeted. Methods: Prospective study carried out in poison control center (P.C.C.)of Ain Shams University Hospitals, 25 cases of acute methanol poisoned patients studied for history, complete ocular and systemic examination details, time to presentation, amount of alcohol ingested, and results of laboratory investigations, such as, arterial pH, methanol levels, bicarbonate levels, and, therapy administered. Twelve patients of them, have been given pulse steroids. Visual acuity (VA), pupillary reaction, and fundus findings were assessed at presentation and 3 months after discharge. Statistical Analysis: Was done by chi square test, Fisher exact test& independent t-test using SPSS 20 version software for studying the significance. Receiver operating characteristic curve (ROC) was used to assess the best cut off point with its area under curve (AUC), sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results & Conclusion: Blood pH at admission is an excellent predictor for final visual outcome in methanol induced optic neuritis, with best cut off point: ≤ 7.06 for poor outcome. Reactivity of pupils at admission was a significant prognostic factor, whereas reactive pupil means good visual outcome, and dilated non-reactive pupil predicts final deterioration and blindness .Two thirds of cases who received pulse steroid therapy had improved by the final follow up at 3 months, with a dramatic effect on fundus finding and visual acuity in some cases. Hemodialysis is a good treatment for methanol toxicity associated with decreased mortalities in a highly significant manner.

Influence of Winemaking Procedure and Grape Variety on the Colour and Composition of Young Red Wines

The influence of winemaking procedure and grape variety on the colour and composition of young red wines was evaluated. For this purpose, Tannat, Syrah and Merlot wines were elaborated in Uruguay in 2011. Traditional maceration (TM), the addition of pectolytic enzymes (ENZ) and cold pre-fermentative maceration before traditional maceration (CPM) were the alternative procedures of winemaking tested. Two batches of grapes (70 kg each) were employed for each winemaking procedure. Tannat wines had the highest colour intensity, red colour (a*), and anthocyanin, proanthocyanidin and alcohol content, and the lowest luminosity (L*) and pH values. CPM increased the colour intensity and total polyphenol, anthocyanin and proanthocyanidin content in Tannat and Merlot wines. Pectolytic additions enhanced colour intensity and red colour and decreased the luminosity in all wines. Meanwhile, enzyme additions enhanced proanthocyanidin content in all cases. Pectolytic enzyme significantly increased the methanol levels of the wines. Nevertheless, the amounts of this compound are far within maximum acceptable limits. Principal component analysis of the data shows significant separation between the wines of each variety, since the colour and composition are largely related to the cultivar and the vintage, despite the effect of the winemaking procedures.

English

An on-line methanol sensor system was developed using a methanol probe, methanol sensor unit and peristaltic pump. The system was commanded using data acquisition (DAQ) and LabVIEW software. Calibration of the methanol sensor system was done in a medium environment with yeast cells during cells adaptation to methanol metabolism after glycerol feeding was stopped. The correlation equations between voltage output signal from the methanol sensor unit and residual methanol in culture broth were created with third order polynomial regression. This developed system was implemented for on-line methanol control in recombinant human serum albumin (rHSA) protein production by P. pastoris KM71 at methanol levels of 4 and 10 g/l with controlled fluctuations at 13.0 and 11.3% of oscillation, respectively. The accumulated amounts of recombinant protein from two levels of methanol concentration controls (4 and 10 g/l) were similar but the proteins were produced at a different rate related with methanol concentration in the broth. Therefore, the control at 10 g/l methanol had a higher production rate (0.53 mg-protein/g dry-cell&times;h) than 4 g/l methanol control (0.38 mg-protein/g dry-cell&times;h) as it reached the maximum protein concentration in a shorter time, even though its cell yield was less than that of 4 g/l methanol control. At the end of the experiments, the high cell density environment caused both cell and protein reduction by cell autolysis and protease degradation. However, the protein decrease could be prevented by taking protein induction at a low temperature and a pH where protease does not function. &nbsp; Key words: Methanol monitoring, methanol sensor, on-line methanol, Pichia pastoris, recombinant human serum albumin.

Epimeric Face-Selective Oxidations and Diastereodivergent Transannular Oxonium Ion Formation Fragmentations: Computational Modeling and Total Syntheses of 12-Epoxyobtusallene IV, 12-Epoxyobtusallene II, Obtusallene X, Marilzabicycloallene C, and Marilzabicycloallene D.

The total syntheses of 12-epoxyobtusallene IV, 12-epoxyobtusallene II, obtusallene X, marilzabicycloallene C, and marilzabicycloallene D as halogenated C15-acetogenin 12-membered bicyclic and tricyclic ether bromoallene-containing marine metabolites from Laurencia species are described. Two enantiomerically pure C4-epimeric dioxabicyclo[8.2.1]tridecenes were synthesized by E-selective ring-closing metathesis where their absolute stereochemistry was previously set via catalytic asymmetric homoallylic epoxidation and elaborated via regioselective epoxide-ring opening and diastereoselective bromoetherification. Epimeric face-selective oxidation of their Δ12,13 olefins followed by bromoallene installation allowed access to the oppositely configured 12,13-epoxides of 12-epoxyobtusallene II and 12-epoxyobtusallene IV. Subsequent exploration of their putative biomimetic oxonium ion formation-fragmentations reactions revealed diastereodivergent pathways giving marilzabicycloallene C and obtusallene X, respectively. The original configurations of the substrates evidently control oxonium ion formation and their subsequent preferred mode of fragmentation by nucleophilic attack at C9 or C12. Quantum modeling of this stereoselectivity at the ωB97X-D/Def2-TZVPPD/SCRF = methanol level revealed that in addition to direction resulting from hydrogen bonding, the dipole moment of the ion-pair transition state is an important factor. Marilzabicycloallene D as a pentahalogenated 12-membered bicyclic ether bromoallene was synthesized by a face-selective chloronium ion initiated oxonium ion formation-fragmentation process followed by subsequent bromoallene installation.

Toxicological Chemical Analysis of Methanol in Blood of Patients with Acute Ethanol Intoxication for Determining Detectable Quantities of Methanol and Analysis of the Correlation Between Ingested Alcohol

Summary The aim of the study was to carry out a toxicological chemical analysis of methanol in detectable quantities in the blood of patients with acute alcohol intoxication. Blood samples from 85 patients with acute alcohol intoxication were analysed for the presence of methanol. All patients with acute methanol intoxication were excluded from the study. The methods of gas chromatography with vapor-phase analysis (head-space) and flame ionization detection (FID) were used. The limit of detection (LOD=0.015 g/L) and the limit of quantification (LOQ=0.025 g/L) of methanol in whole blood were evaluated. In 30% of the cases, methanol was found in the blood in detectable quantities. The levels of methanol were on the average 5 to 6 times lower than the toxic methanol level (0200 g/L) and they were not due to natural metabolic processes (ingestion of fruit, fruit juices or vegetables). No reliable statistically linear correlation between the concentration of ethanol and methanol was found. Methanol subintoxications are major factors in alcohol intoxications, in which the quantity of the alcohol ingested is not as important as its quality. Chronic methanol subintoxication of people who often consume alcohol of poor quality is discussed.

Quality improvement and geographical indication of cachaça (Brazilian spirit) by using locally selected yeast strains.

In order to improve the quality and to create a biological basis for obtainment of the protected denomination of origin (PDO), indigenous yeast were isolated and characterized for use in Salinas city (the Brazilian region of quality cachaça production). Seven thousand and two hundred yeast colonies from 15 Salinas city distilleries were screened based on their fermentative behaviour and the physicochemical composition of cachaça. Molecular polymorphic analyses were performed to characterize these isolates. Two Saccharomyces cerevisiae strains (nos. 678 and 680) showed appropriate characteristics to use in the cachaça production: low levels of acetaldehyde and methanol, and high ethyl lactate/ethyl acetate ratio respectively. They also presented polymorphic characteristics more closely related between themselves even when compared to other strains from Salinas. The application of selected yeast to cachaça production can contribute for the improvement of the quality product as well as be used as a natural marker for PDO. This study suggests that the use of selected yeast strains could contribute to obtain a cachaça similar to those produced traditionally, while getting wide acceptation in the market, yet presenting more homogeneous organoleptic characteristics, and thus contributing to the PDO implementation.

Crude glycerol by transesterification process from used cooking oils: Characterization and potentialities on hydrogen bioproduction

This study evaluated the potential bioconversion of crude glycerol from biodiesel production, applying used cooking oil for biohydrogen production by fermentative bacteria consortia. The pretreatment of crude glycerol was made by pH adjustment. Heat treatment of the inocula and initial pH 5.5 were applied to select hydrogen-producing bacteria and inactivate hydrogen-consumers microorganisms. The inocula tested were: (I) granular sludge from the thermophilic UASB reactor used on the treatment of vinasse and (II) granular sludge from the UASB reactor used on the treatment of sanitary sludge for the assays (1) and (2), respectively. The characterization of crude glycerol presented high levels of alkalinity, methanol and soap that may be inhibitory to biologic processes of H2 production. The assays were carried in anaerobic batch reactors in order to verify the efficiencies of crude glycerol to H2 generations by the microbial consortia (20%) at 37 °C, initial pH 5.5, with 20.0 g COD L−1 glycerol. The cumulative production of hydrogen for the assays (1) and (2) were, respectively, (mmol H2 L−1) 28.49 ± 1.55 and 19.14 ± 1.67. The subsequent yields were obtained as follows: 2.2 moL H2 mol−1 glycerol and 1.1 moL H2 mol−1 glycerol, respectively. The used cooking oil was an efficient waste for bioconversion of crude glycerol to H2 production.

Eight fatalities due to drinking methanol-tainted alcohol in Pakistan: A case report

Methanol has a widespread commercial use as a solvent in paints, varnishes, anti-freeze solutions and denaturant for ethanol. Exposure may occur due to accidental, suicidal ingestion or as a result of consuming adulterated liquor. Fatalities were reported in Pakistan in an incident after consuming methanol-tainted liquor. Postmortem specimens of eight deceased males, ages ranged from 16 to 40yrs, were submitted for toxicological analysis. Presence of blurred vision, severe metabolic acidosis with decreased serum bicarbonate level, increased serum osmolality and mean anion gap before death strongly suggested methanol toxicity. Headspace gas chromatograph coupled to flame ionization detector was used to quantify volatiles in blood and stomach contents of victims. Lethal levels of methanol in addition to ethanol were detected. The most probable mechanism of methanol-related deaths was sudden cessation of respiration due to inhibition of cytochrome oxidase that led to histotoxic hypoxia.

Determination of methanol in Iranian herbal distillates.

Herbal distillates have been used as beverages, for flavoring, or as phytomedicines in many countries for a long time. Recently, the occurrence of blindness after drinking herbal distillates has created concerns in Iran. The aim of this study was to determine the concentrations of methanol in herbal distillates produced in Iran. Eighty-four most commonly used herbal distillates purchased from herbal distillate factories were analyzed for methanol contents by gas chromatography and flame ionization detection, with ethanol as internal standard. In 15 herbal distillates, the methanol concentration was below the limit of quantitation. The methanol concentrations in all samples ranged from 43 to 277 mg/L. Forty-five samples contained methanol in excess of the Iranian standard. The maximum concentration was found in an herbal distillate of Mentha piperita (factory E) (277±12), and the minimum in a distillate of Carum carvi (factory B) (42.6 ± 0.5). Since the 45 Iranian herbal distillates containing methanol levels were beyond the legal limits according to the Iranian standard, it seems necessary to monitor the amount of methanol and give a warning to watch out for the latent risk problem of methanol uptake, and establish a definitive relationship between the degree of intoxication observed and the accumulation of methanol in the blood.