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Fulltext Bioethanol production from agarophyte red seaweed, Gelidium elegans, using a novel sample preparation method for analysing bioethanol content by gas chromatography

Hessami MJ, Cheng SF, Ambati RR, Yin YH, Phang SM

3 Biotech, 2019 Jan;9(1):25.
PMID: 30622863 DOI: 10.1007/s13205-018-1549-8

In this study, Gelidium elegans is investigated for ethanol production. A combination of factors including different temperatures, acid concentration and incubation time was evaluated to determine the suitable saccharification conditions. The combination of 2.5% (w/v) H2SO4 at 120 °C for 40 min was selected for hydrolysis of the seaweed biomass, followed by purification, and fermentation to yield ethanol. The galactose and glucose were dominant reducing sugars in the G. elegans hydrolysate and under optimum condition of dilute acid hydrolysis, 39.42% of reducing sugars was produced and fermentation resulted in ethanol concentration of 13.27 ± 0.47 g/L. A modified method was evaluated for sample preparation for gas chromatography (GC) analysis of the ethanol content. A solvent mixture of acetonitrile and iso-butanol precipitated dissolved organic residues and reduced water content in GC samples at least by 90%. Results showed that this method could be successfully used for bioethanol production from seaweed.

Matched MeSH terms: Ethanol
Fulltext Chemical and structural changes of pretreated empty fruit bunch (EFB) in ionic liquid-cellulase compatible system for fermentability to bioethanol

Elgharbawy AA, Alam MZ, Moniruzzaman M, Kabbashi NA, Jamal P

3 Biotech, 2018 May;8(5):236.
PMID: 29744268 DOI: 10.1007/s13205-018-1253-8

The pretreatment of empty fruit bunch (EFB) was conducted using an integrated system of IL and cellulases (IL-E), with simultaneous fermentation in one vessel. The cellulase mixture (PKC-Cel) was derived from Trichoderma reesei by solid-state fermentation. Choline acetate [Cho]OAc was utilized for the pretreatment due to its biocompatibility and biodegradability. The treated EFB and its hydrolysate were characterized by the Fourier transform infrared spectroscopy, scanning electron microscopy, and chemical analysis. The results showed that there were significant structural changes in EFB after the treatment in IL-E system. The sugar yield after enzymatic hydrolysis by the PKC-Cel was increased from 0.058 g/g of EFB in the crude sample (untreated) to 0.283 and 0.62 ± 06 g/g in IL-E system after 24 and 48 h of treatment, respectively. The EFB hydrolysate showed the eligibility for ethanol production without any supplements where ethanol yield was 0.275 g ethanol/g EFB in the presence of the IL, while lower yield obtained without IL-pretreatment. Moreover, it was demonstrated that furfural and phenolic compounds were not at the level of suppressing the fermentation process.

Matched MeSH terms: Ethanol
Fulltext Optimization of thermostable organic solvent-tolerant lipase production by thermotolerant Rhizopus sp. using solid-state fermentation of palm kernel cake

Riyadi FA, Alam MZ, Salleh MN, Salleh HM

3 Biotech, 2017 Oct;7(5):300.
PMID: 28884067 DOI: 10.1007/s13205-017-0932-1

This study enhanced the production of thermostable organic solvent-tolerant (TS-OST) lipase by locally isolated thermotolerant Rhizopus sp. strain using solid-state fermentation (SSF) of palm kernel cake (PKC). The optimum conditions were achieved using a series of statistical approaches. The cultivation parameters, which include fermentation time, moisture content, temperature, pH, inoculum size, various carbon and nitrogen sources, as well as other supplements, were initially screened by the definitive screening design, and one-factor-at-a-time using PKC as the basal medium. Three significant factors (olive oil concentration, pH, and inoculum size) were further optimized using face-centred central composite design. The results indicated a successful and significant improvement of lipase activity by almost two-fold compared to the initial screening production. The findings showed that the optimal conditions were 2% (v/w) inoculum size, 2% (v/w) olive oil, 0.6% (w/w) peptone, 2% (v/w) ethanol, 70% moisture content at initial pH 10.0 and 45 °C within 72 h of fermentation. Process optimization resulted in maximum lipase activity of 58.63 U/gram dry solids (gds). The analysis of variance showed that the statistical model was significant (p value <0.0001) and reliable with a high value of R2 (0.98) and adjusted R2 (0.96). This indicates a better correlation between the actual and predicted responses of lipase production. By considering this study, the low-cost PKC through SSF appears to be promising in the utilization of agro-industrial waste for TS-OST lipase production. This is because satisfactory enzyme activity could be attained that promises industrial applications.

Matched MeSH terms: Ethanol
Fulltext A New Model of Alcoholic Fermentation under a Byproduct Inhibitory Effect

Zentou H, Zainal Abidin Z, Yunus R, Awang Biak DR, Abdullah Issa M, Yahaya Pudza M

ACS Omega, 2021 Feb 16;6(6):4137-4146.
PMID: 33644536 DOI: 10.1021/acsomega.0c04025

Despite the advantages of continuous fermentation whereby ethanol is selectively removed from the fermenting broth to reduce the end-product inhibition, this process can concentrate minor secondary products to the point where they become toxic to the yeast. This study aims to develop a new mathematical model do describe the inhibitory effect of byproducts on alcoholic fermentation including glycerol, lactic acid, acetic acid, and succinic acid, which were reported as major byproducts during batch alcoholic fermentation. The accumulation of these byproducts during the different stages of batch fermentation has been quantified. The yields of total byproducts, glycerol, acetic acid, and succinic acid per gram of glucose were 0.0442, 0.023, 0.0155, and 0.0054, respectively. It was found that the concentration of these byproducts linearly increases with the increase in glucose concentration in the range of 25-250 g/L. The results have also showed that byproduct concentration has a significant inhibitory effect on specific growth coefficient (μ) whereas no effect was observed on the half-velocity constant (Ks). A new mathematical model of alcoholic fermentation was developed considering the byproduct inhibitory effect, which showed a good performance and more accuracy compared to the classical Monod model.

Matched MeSH terms: Ethanol
Fulltext Synthesis and Thermal Properties of Resorcinol-Furfural Thermosetting Resin

Liu J, Xuan D, Chai J, Guo D, Huang Y, Liu S, et al.

ACS Omega, 2020 May 05;5(17):10011-10020.
PMID: 32391489 DOI: 10.1021/acsomega.0c00365

A mild and effective synthesis of resorcinol-furfural (RF) thermosetting resin was proposed with ethanol as a distinctive solvent, which, as a usually neglected factor, was shown to not only help form a homogeneous reaction system but also observably reduce the energy barriers between the early intermediates and transition states in addition reactions by explicit solvent effects, drawn from theoretical calculation conclusions. Besides, the para-additions on aromatic rings were more dominant than ortho-additions with the same reactants, which affected the final link types of monomers verified by Fourier transform infrared spectroscopy and two-dimensional nuclear magnetic resonance tests. The prepared resin can be assigned to a relatively fast gel speed and a high residual mass (65.25%) after pyrolysis in a N2 atmosphere by adjusting the molar ratios of F to R, and the curing of that was a complex reaction, with a curing temperature around 149 °C and an activation energy of about 49.11 kJ mol-1 obtained by the Kissinger method.

Matched MeSH terms: Ethanol
Fulltext Kinetic modelling of ethanol fermentation process using cassava (Manihot esculenta) starch as carbon source

Low, C.Y., Hii, S.L., Leong, L.K., Yim, Y.Y., Tan, H.W.

ASM Science Journal, 2012;6(1):61-66.
MyJurnal

Cassava starch was used as feedstock for production of bioethanol by Saccharomyces cerevisiae. The cassava starch was hydrolyzed using commercial α-amylase and glucoamylase enzymes followed by a batch ethanol fermentation process using saccharified starch slurry. By using 110 g/L of reducing sugar from saccharified starch slurry, the ethanol yield was promising with maximum ethanol concentration of 20.6 g/L recorded after 55 hours of cultivation process. Three different models - the Logistic model, Luedeking-Piret-like equation and Gompertz equation - were used to characterize and explain the cell growth, reducing sugar consumption and production formation, respectively. The kinetic parameters were estimated by fitting the experimental data to the proposed models using non-linear regression analysis. The correlation coefficient r2 values for the Logistic model, Luedeking-Piret-like equation and the Gompertz equation were 0.994, 0.996 and 0.990, respectively. The high correlation coefficient values indicate that the proposed models were able to describe the ethanol fermentation process.

Matched MeSH terms: Ethanol
Fulltext Prevention of ethanol-induced gastric mucosal Injury by Ocimum basilicum seed extract in rats

Mahmood, A.A., Sidik, K., Fouad, H.M.

ASM Science Journal, 2007;1(1):1-6.
MyJurnal

Ocimum basilicum seed extracts were found to possess significant anti-ulcer activity against ethanol-induced ulceration in experimental animal models. Three groups of adult male rats were used, with each group consisting of six rats. Oral administration of absolute ethanol to rats pre-treated with 10% Tween 20® (Group 1) produced extensive haemorrhagic lesions of the gastric mucosa. Rats orally pre-treated with O. basilicum extract suspended in 10% Tween 20® (Group 2) or cimetidine in 10% Tween 20® (Group 3), 30 min before oral administration of absolute alcohol had significantly reduced (p

Matched MeSH terms: Ethanol
Fulltext In vivo acute toxicity and anti-gastric evaluation of a novel dichloro Schiff base: Bax and HSP70 alteration

Saremi K, Rad SK, Khalilzadeh M, Hussaini J, Majid NA

Acta Biochim Biophys Sin (Shanghai), 2020 Jan 02;52(1):26-37.
PMID: 31889181 DOI: 10.1093/abbs/gmz140

Chlorine is shown to possess anti-gastric ulcer activity, since it can inactivate Helicobacter pylori, which is regarded as one of the most common risk factors for causing gastric problems. In the current study, the gastroprotective property of a novel dichloro-substituted Schiff base complex, 2, 2'- [-1, 2-cyclohexanediylbis(nitriloethylidyne)] bis(4-chlorophenol) (CNCP), against alcohol-induced gastric lesion in SD rats was assessed. SD rats were divided into four groups, i.e. normal, ulcer control, testing, and reference groups. Ulcer area, gastric wall mucus, and also gastric acidity of the animal stomachs were measured. In addition, antioxidant activity of CNCP was evaluated and its safe dose was identified. Immunohistochemistry staining was also carried to evaluate two important proteins, i.e. Bcl2-associated X protein (Bax) and heat shock protein 70 (HSP70). Moreover, the activities of super oxide dismutase and catalase, as well as the levels of prostaglandin E2 (PGE2) and malondialdehyde (MDA) were also measured. Antioxidant activity of CNCP was approved via the aforementioned experiments. Histological evaluations showed that the compound possesses stomach epithelial defense activity. Additionally, periodic acid-Schiff staining exhibited over-expression of HSP70 and down-expression of Bax protein in the CNCP-treated rats. Moreover, CNCP caused deceased MDA level and elevated PGE2 level, and at the same time increased the activities of the two enzymes.

Matched MeSH terms: Ethanol/adverse effects; Ethanol/pharmacology
Redetermination of hydronium perchlorate at 193 and 293 K

Rahman AA, Usman A, Chantrapromma S, Fun HK

Acta Crystallogr C, 2003 Sep;59(Pt 9):i92-4.
PMID: 12944636

A sample of hydronium perchlorate, H(3)O(+) x ClO(4)(-), crystallized from ethanol at ambient temperature, was found to be orthorhombic (space group Pnma) at both 193 and 293 K, with no phase transition observed in this temperature range. This contrasts with the earlier observation [Nordman (1962). Acta Cryst. 15, 18-23] of a monoclinic phase (space group P2(1)/n) at 193 K for crystals grown at that temperature from perchloric acid. The hydronium and perchlorate ions lie across a mirror plane but it is not possible to define at either temperature a simple description of the H-atom positions due to the three-dimensional tumbling of the hydronium cation.

Matched MeSH terms: Ethanol
Tris(8-quinolinolato-N,O)cobalt(III) ethanol solvate

Shanmuga Sundara Raj S, Razak IA, Fun HK, Zhao PS, Jian F, Yang X, et al.

Acta Crystallogr C, 2000 Apr 15;56(Pt 4):E130-1.
PMID: 15263175

In the crystal of the title complex, [Co(C(9)H(6)NO)(3)].C(2)H(5)OH, the central Co atom has a distorted octahedral coordination comprised of three N atoms and three O atoms from the three 8-quinolinolato ligands. The three Co-O bond distances are in the range 1.887 (2)-1.910 (2) A, while the three Co-N bond distances range from 1.919 (2) to 1.934 (2) A. The solvent ethanol molecule forms an intermolecular O-H.O hydrogen bonding with a quinolinolato ligand.

Matched MeSH terms: Ethanol
Fulltext Chemical composition, antioxidant, antimicrobial and antiviral activities of the leaf extracts of Syzygium myrtifolium

Ahmad MA, Lim YH, Chan YS, Hsu CY, Wu TY, Sit NW

Acta Pharm, 2022 Jun 01;72(2):317-328.
PMID: 36651512 DOI: 10.2478/acph-2022-0013

This study was conducted to evaluate the chemical composition and biological activities of the leaf extracts of Syzygium myrtifolium Walp. (Myrtaceae). The results indicate that the leaf extracts of S. myrtifolium contain various classes of phytochemicals (alkaloids, anthraquinones, flavonoids, phenolics, saponins, tannins and triterpenoids) and possess antioxidant, antibacterial, antifungal and antiviral activities. Ethyl acetate, ethanol, methanol, and water extracts exhibited significantly higher (p < 0.05) oxygen radical absorbance capacity and ferric-reducing antioxidant power than the hexane and chloroform extracts. However, all extracts exhibited stronger inhibitory activity against four tested species of yeasts (minimal inhibitory concentration: 0.02-0.31 mg mL-1) than against six tested species of bacteria (minimal inhibitory concentration: 0.16-1.25 mg mL-1). The ethanolic extract offered the highest protection of Vero cells (viability > 70 %) from the cytopathic effect caused by the Chikungunya virus while the ethyl acetate extract showed significant replication inhibitory activity against the virus (p < 0.001) using the replicon-enhanced green fluorescent protein reporter system.

Matched MeSH terms: Ethanol/chemistry
Influence of different extraction conditions on antioxidant properties of soursop peel

Lee WZ, Chang SK, Khoo HE, Sia CM, Yim HS

Acta Sci Pol Technol Aliment, 2016 Oct-Dec;15(4):419-428.
PMID: 28071019 DOI: 10.17306/J.AFS.2016.4.40

Soursop is a healthy fruit. Peels form about 20% of the soursop fruit and are usually discarded as waste product. With a view to utilizing soursop peel as a source of valuable compounds, this study aimed to investigate the influence of different extraction conditions on total phenolic content (TPC) and antioxidant capacity (AC) of soursop (Annona muricata L.) peel.

Matched MeSH terms: Ethanol/chemistry
The beer component hordenine inhibits alcohol addiction-associated behaviours in mice

Li Y, Vogel C, Kalinichenko LS, Hübner H, Weikert D, Schaefer N, et al.

Addict Biol, 2023 Aug;28(8):e13305.
PMID: 37500485 DOI: 10.1111/adb.13305

Alcohol consumption is a widespread behaviour that may eventually result in the development of alcohol use disorder (AUD). Alcohol, however, is rarely consumed in pure form but in fruit- or corn-derived preparations, like beer. These preparations add other compounds to the consumption, which may critically modify alcohol intake and AUD risk. We investigated the effects of hordenine, a barley-derived beer compound on alcohol use-related behaviours. We found that the dopamine D2 receptor agonist hordenine (50 mg/kg) limited ongoing alcohol consumption and prophylactically diminished relapse drinking after withdrawal in mice. Although not having reinforcing effects on its own, hordenine blocked the establishment of alcohol-induced conditioned place preference (CPP). However, it independently enhanced alcohol CPP retrieval. Hordenine had a dose-dependent inhibitory effect on locomotor activity. Chronic hordenine exposure enhanced monoamine tissue levels in many brain regions. Further characterization revealed monoaminergic binding sites of hordenine and found a strong binding on the serotonin and dopamine transporters, and dopamine D3 , and adrenergic α1A and α2A receptor activation but no effects on GABAA receptor or glycinergic signalling. These findings suggest that natural ingredients of beer, like hordenine, may work as an inhibitory and use-regulating factor by their modulation of monoaminergic signalling in the brain.

Matched MeSH terms: Ethanol/pharmacology
Fulltext Alcohol neurolysis of lateral femoral cutaneous nerve for recurrent meralgia paresthetica

Chen CK, Phui VE, Saman MA

Agri, 2012;24(1):42-4.
PMID: 22399128 DOI: 10.5505/agri.2012.47450

Meralgia paresthetica is an entrapment mononeuropathy of lateral femoral cutaneous nerve, which results in localized area of paresthesia and numbness on the anterolateral aspect of the thigh. We describe the use of alcohol neurolysis of lateral femoral cutaneous nerve in a 74-year-old female who presented with paresthesia over antero-lateral aspect of her left thigh, which was consistent with meralgia paresthetica. Diagnostic block with local anaesthetic confirmed the diagnosis but only archieved temporary pain relief. Alcohol neurolysis was then offered and patient responded well with no complication. The patient experienced prolonged pain relief at 6-month follow-up, with return of ability to ambulate and perform daily activity. Alcohol neurolysis of lateral femoral cutaneous nerve is safe, effective and able to provide sustained pain relief for recurrent meralgia paresthetica.

Matched MeSH terms: Ethanol/administration & dosage*
The effects of acute ethanol administration on ethanol withdrawal-induced anxiety-like syndrome in rats: A biochemical study

Kumar J, Hapidin H, Get Bee YT, Ismail Z

Alcohol, 2016 Feb;50:9-17.
PMID: 26626323 DOI: 10.1016/j.alcohol.2015.10.001

Withdrawal from long-term ethanol consumption results in overexcitation of glutamatergic neurotransmission in the amygdala, which induces an anxiety-like syndrome. Most alcoholics that suffer from such symptoms frequently depend on habitual drinking as self-medication to alleviate their symptoms. Metabotropic glutamate receptor subtype 5 (mGlu5) and protein kinase C (PKC) epsilon have been reported to mediate acute and chronic effects of ethanol. This study explores the changes in mGlu5 and PKC epsilon in the amygdala following acute administration of ethanol during ethanol withdrawal (EW) induced anxiety. Male Wistar rats were fed a modified liquid diet containing low-fat cow milk, sucrose, and maltodextrin, with a gradual introduction of 2.4%, 4.8% and 7.2% ethanol for 20 days. Six hours into EW, the rats were intraperitoneally injected with normal saline and ethanol (2.5 g/kg, 20% v/v), and exposed to open-field and elevated plus maze tests. Then, amygdala tissue was dissected from the rat brain for Western blot and gene expression studies. EW-induced anxiety was accompanied by a significant increase in mGlu5, total PKC epsilon, and phosphorylated PKC epsilon protein levels, and also of mRNA of mGlu5 (GRM5) in the amygdala. Acute administration of ethanol significantly attenuated EW-induced anxiety as well as an EW-induced increase in GRM5. The acute challenge of ethanol to EW rats had little effect on the phosphorylated and total protein levels of PKC epsilon in the amygdala. Our results demonstrate that amygdala PKC epsilon may not be directly involved in the development of anxiety following EW.

Matched MeSH terms: Ethanol
Effect of gestational ethanol exposure on long-term memory formation in newborn chicks

Rao V, Chaudhuri JD

Alcohol, 2007 Sep;41(6):433-9.
PMID: 17624712

Fetal alcohol syndrome (FAS), a condition occurring in some children of mothers who have consumed alcohol during pregnancy, is characterized by craniofacial malformations, and physical and mental retardation. It is significant that even children with history of gestational ethanol exposure but relatively unaffected overall IQ performance, often exhibit learning difficulties and behavioral problems, suggestive of impaired memory formation. Hence, the specific aim of this study was to examine memory formation in chicks exposed to ethanol during early gestation toward the understanding of neurobehavioral disturbances in FAS. Chicks were exposed to alcohol on gestational days 1-3 by injection of ethanol into the airspace of freshly fertilized eggs. The effects of prenatal ethanol on physical growth and development, and memory formation were studied. The one-trial passive avoidance learning paradigm in 1-day-old chicks was used to study memory formation in these chicks. It was observed that chick embryos exposed to 10% ethanol on gestational days 1-3 had significant reduction in all body parameters when compared with appropriate controls. Further, ethanol-exposed chick embryos had significantly impaired (Pethanol exposure during early pregnancy on developing chick embryos in general and on memory formation in particular. Hence, it is suggested that impairment in LTM could be a fundamental mechanism for learning disorders and neurobehavioral abnormalities observed in FAS.

Matched MeSH terms: Ethanol/toxicity*
Relationship Between Alcohol Co-Ingestion and Clinical Outcome in Pesticide Self-Poisoning: A Systematic Review and Meta-Analysis

Dhanarisi J, Perera S, Wijerathna T, Gawarammana I, Shihana F, Pathiraja V, et al.

Alcohol Alcohol, 2023 Jan 09;58(1):4-12.
PMID: 36172715 DOI: 10.1093/alcalc/agac045

AIM: Alcohol is a commonly co-ingested compound during self-poisoning with pesticides. Clinical experiences suggest alcohol co-ingestion (or withdrawal) makes patient management more difficult after self-poisoning and may contribute to poor clinical outcomes. We aimed to systematically review the world literature to explore the relationship between alcohol co-ingestion and outcome in pesticide self-poisoning.
METHODS: We searched 13 electronic databases and Google scholar, conducted citation searching and a review of reference lists to find studies which investigated the relationship of alcohol with clinical outcome of pesticide self-poisoning in different countries. Thirteen studies, including 11 case series/reports and two cohort studies were considered for inclusion.
RESULTS: Meta-analysis showed that alcohol co-ingestion in pesticide self-poisoning was associated with increased risk of death [odds ratio (OR) 4.9, 95% confidence interval (CI) 2.9-8.2 P<0.0001] and that alcohol co-ingested group required intubation eight times more often than non-co-ingested group in organophosphorus insecticide self-poisoning (OR 8.0, 95% CI 4.9-13.0 P<0.0001). Cases who co-ingested alcohol were older than non-alcohol group in two studies. One cohort study demonstrated that alcohol co-ingestion was associated with larger pesticide ingestions but did not itself affect the outcome.
CONCLUSIONS: This systematic review indicates that alcohol co-ingestion may worsen clinical outcome in pesticide self-poisoning.

Matched MeSH terms: Ethanol
Improvement of the butanol production selectivity and butanol to acetone ratio (B:A) by addition of electron carriers in the batch culture of a new local isolate of Clostridium acetobutylicum YM1

Nasser Al-Shorgani NK, Kalil MS, Wan Yusoff WM, Shukor H, Hamid AA

Anaerobe, 2015 Dec;36:65-72.
PMID: 26439644 DOI: 10.1016/j.anaerobe.2015.09.008

Improvement in the butanol production selectivity or enhanced butanol:acetone ratio (B:A) is desirable in acetone-butanol-ethanol (ABE) fermentation by Clostridium strains. In this study, artificial electron carriers were added to the fermentation medium of a new isolate of Clostridium acetobutylicum YM1 in order to improve the butanol yield and B:A ratio. The results revealed that medium supplementation with electron carriers changed the metabolism flux of electron and carbon in ABE fermentation by YM1. A decrease in acetone production, which subsequently improved the B:A ratio, was observed. Further improvement in the butanol production and B:A ratios were obtained when the fermentation medium was supplemented with butyric acid. The maximum butanol production (18.20 ± 1.38 g/L) was gained when a combination of methyl red and butyric acid was added. Although the addition of benzyl viologen (0.1 mM) and butyric acid resulted in high a B:A ratio of 16:1 (800% increment compared with the conventional 2:1 ratio), the addition of benzyl viologen to the culture after 4 h resulted in the production of 18.05 g/L butanol. Manipulating the metabolic flux to butanol through the addition of electron carriers could become an alternative strategy to achieve higher butanol productivity and improve the B:A ratio.

Matched MeSH terms: Ethanol
Facile hydrothermal growth graphene/ZnO nanocomposite for development of enhanced biosensor

Low SS, Tan MT, Loh HS, Khiew PS, Chiu WS

Anal Chim Acta, 2016 Jan 15;903:131-41.
PMID: 26709306 DOI: 10.1016/j.aca.2015.11.006

Graphene/zinc oxide nanocomposite was synthesised via a facile, green and efficient approach consisted of novel liquid phase exfoliation and solvothermal growth for sensing application. Highly pristine graphene was synthesised through mild sonication treatment of graphite in a mixture of ethanol and water at an optimum ratio. The X-ray diffractometry (XRD) affirmed the hydrothermal growth of pure zinc oxide nanoparticles from zinc nitrate hexahydrate precursor. The as-prepared graphene/zinc oxide (G/ZnO) nanocomposite was characterised comprehensively to evaluate its morphology, crystallinity, composition and purity. All results clearly indicate that zinc oxide particles were homogenously distributed on graphene sheets, without any severe aggregation. The electrochemical performance of graphene/zinc oxide nanocomposite-modified screen-printed carbon electrode (SPCE) was evaluated using cyclic voltammetry (CV) and amperometry analysis. The resulting electrode exhibited excellent electrocatalytic activity towards the reduction of hydrogen peroxide (H2O2) in a linear range of 1-15 mM with a correlation coefficient of 0.9977. The sensitivity of the graphene/zinc oxide nanocomposite-modified hydrogen peroxide sensor was 3.2580 μAmM(-1) with a limit of detection of 7.4357 μM. An electrochemical DNA sensor platform was then fabricated for the detection of Avian Influenza H5 gene based on graphene/zinc oxide nanocomposite. The results obtained from amperometry study indicate that the graphene/zinc oxide nanocomposite-enhanced electrochemical DNA biosensor is significantly more sensitive (P

Matched MeSH terms: Ethanol
Inexpensive Portable Infrared Device to Detect and Quantify Alcohols in Hand Sanitizers for Public Health and Safety

Ng JK, Tay FH, Wray PS, Mohd Saberi SS, Ken Ting KK, Khor SM, et al.

Anal Chem, 2021 11 16;93(45):15015-15023.
PMID: 34730329 DOI: 10.1021/acs.analchem.1c02652

The onset of Covid-19 pandemic has resulted in the exponential growth of alcohol-based hand rub (ABHR)/hand sanitizer use. Reports have emerged of ABHR products containing methanol, a highly toxic compound to humans, exposing users to acute and chronic medical illnesses. While gas chromatography-mass spectrometry (GC-MS) remains the gold-standard method for the detection and identification of impurities in ABHRs, there exist limitations at widespread volume testing. This paper demonstrates the capability of an inexpensive portable pyroelectric linear array infrared spectrometer to rapidly test ABHR and compare the performance with a benchtop Fourier transform infrared spectrometer and HS-GC-MS. Multicomponent partial least square quantification models were built with performance found to be comparable between the two spectrometers and with the HS-GC-MS. Furthermore, the portable spectrometer was field-tested with real-world samples in Malaysia on both retail products (Group A) and freely deployed public dispensers (Group B) between May and November 2020. A total of 386 samples were tested. Only 75.2% of Group A met the criteria of safe and effective ABHR [no detectable methanol and alcohol concentration above 60% (v/v)], while <50% of Group B did. In addition, 7.4 and 18.8% of Group A and Group B, respectively, were found to contain methanol above permissible limits. The high percentage of sub-standard and methanol-containing samples combined with the frequent use of ABHR by the public highlights the need for and importance of a portable and rapid testing device for widespread screening of ABHR against falsified products and protects the general public.

Matched MeSH terms: Ethanol

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