Ovidius University Annals of Chemistry最新文献

{"title":"Rheology of new lubricating greases made from renewable materials","authors":"Olga V. Săpunaru, Ancaelena E. Sterpu, Cyrille Alode Vodounon, Sibel Osman, Claudia I. Koncsag","doi":"10.2478/auoc-2023-0012","DOIUrl":"https://doi.org/10.2478/auoc-2023-0012","url":null,"abstract":"Abstract Lubricanting greases from waste frying vegetables oils with natural fibers additives could be the answer to the sustainable production of greases. Also, their biodegradability makes them more acceptable for the environment, having in view increasingly strict regulations in domain. In this experimental work, twenty lubricant formulae were created from waste sunflower oil and waste palm oil with calcium or lithium stearate as thickener and cellulose or lignin additives. All were rheologically tested and characterized as Bingham fluid with good consistency and plasticity. The penetration tests confirmed the good consistency, categorizing these products from normal to firm, very firm and hard lubricant greases comparable to those conventionally obtained from mineral oils.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"101 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135806326","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"GC-MS profile and antimicrobial activities of extracts from root of <i>Senna occidentalis</i> Linn.","authors":"Ngozi Francesca Amako, Mary-Ann Nkoli Mgbemena, Sunday Peter Odo","doi":"10.2478/auoc-2023-0009","DOIUrl":"https://doi.org/10.2478/auoc-2023-0009","url":null,"abstract":"Abstract We considered the extraction of plant materials from Senna occidentalis root, and its fractionation monitored by bioassay towards isolating its bioactive principles. Pulverized root sample of Senna occidentalis (fam. leguminaceae) was extracted with methanol using a maceration method. The crude methanol extract (MSo) 6.06 g was partitioned into petroleum ether and ethyl acetate to yield their respective fractions viz: petroleum ether fraction (1.20 g), ethyl acetate fraction (1.86 g) and methanol fraction (2.92 g). The crude methanol extract was analyzed using phytochemical screening, infrared spectroscopy, and gas chromatography/mass spectrometry while the fractions were examined for antimicrobial properties. Phytochemical screening indicated the presence of tannins, phenolics, alkaloids, flavonoids, saponins, cardiac glycosides, phlobatannin, and absence of steroids. The infrared spectrum revealed a broad absorption band at 3437.26 cm -1 due to O-H symmetric stretch in polymeric alcohols, and absorption frequency of 1640.51cm -1 of moderate intensity due to C=O stretch. Enols are easily identified by the broad H-bonded O-H stretch absorption and low C=O stretch frequency as in β-keto enolic esters and phenol acetates, -CO-O-C=C-, (1690-1650 cm -1 ). Gas chromatography/mass spectrometry identified the presence of ten compounds including n -hexadecanoic acid (23.76%), linoleic acid (1.64%), E-9-tetradecenoic acid (4.88%), octadecanoic acid, 2-(2 hydroxyethoxy) ethyl ester (6.24%) and E-2-octadecadecen-1-ol (13.74%). Similar broad spectrum antimicrobial activities were manifested by methanol and ethyl acetate fractions. Escherichia coli and Bacillus cereus were the most susceptible with the highest zone of inhibition of 30 mm and 28 mm respectively at minimum inhibition concentration of 1.35 x10 3 μg/ml. The methanol fraction has the highest potency against the tested pathogens whereas the petroleum ether fraction exhibited activity only on gram negative pathogens. The antimicrobial activities observed in these fractions suggest the presence of active chemical components in the crude methanol root extract of Senna occidentalis thus provides a potential source of novel antimicrobial agents. Further work is however, required to isolate and characterize these bioactive principles.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135806331","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Solubility of acetaminophen in the ethanol and glycerol mixtures at different temperatures","authors":"Nafiseh Gholizadeh, Jalal Hanaee, Elaheh Rahimpour, Abolghasem Jouyban","doi":"10.2478/auoc-2023-0013","DOIUrl":"https://doi.org/10.2478/auoc-2023-0013","url":null,"abstract":"Abstract Acetaminophen solubility in the glycerol and ethanol mixture was determined by a simple shake-flask technique at different temperatures and fitted to some mathematical models and the models’ accuracy was investigated by the computation of the mean relative deviations. The densities of acetaminophen saturated mixtures were also studied by the Jouyban-Acree model. Moreover, the Gibbs and van’t Hoff equations were utilized to compute apparent thermodynamic parameters of the acetaminophen dissolving.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135806327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"End-of-life mobile phones parts contain toxic metals that make them hazardous, but can also serve as resource reserves for such metals","authors":"Bukola Omoyemi Abiodun, Paschal Okiroro Iniaghe","doi":"10.2478/auoc-2023-0011","DOIUrl":"https://doi.org/10.2478/auoc-2023-0011","url":null,"abstract":"Abstract In this study, the concentration of some toxic metals in different parts of end-of-life mobile phones was assessed. Twenty end-of-life mobile phones of different brands and countries of origin, which were widely in use up to the year 2011, were collected from phone repair workshops in Lagos, Nigeria. The collected mobile phones were disassembled into the phone screens, printed wiring boards, plastic casings and batteries. Disassembled parts were individually milled and pulverized, and digested using HCl, HNO 3 and H 2 O 2 . Flame atomic absorption spectrometry was used to quantify some toxic metals (Pb, Cd and Ni) in the digested samples, and the determined concentrations were compared with permissible limits. The average metals concentration in the disassembled parts followed the order: printed wiring boards &gt; batteries &gt; plastic casings &gt; phone screens. The concentrations of Pb and Ni exceeded their toxicity threshold limit concentration in printed wiring boards, while Ni exceeded the limit concentration in batteries. Based on the maximum permissible concentration required by the Restriction of Hazardous Substances (RoHS) Directives, all Cd concentrations were below the limit concentration; Pb and Ni in printed wiring boards exceeded their limit concentrations, while Ni exceeded its permissible concentration in batteries. The results of this study indicate that printed wiring boards and batteries of end-of-life mobile phones are hazardous, and their improper disposal of could cause environmental and health problems. However, considering the very high concentrations of Pb and Ni, these mobile phone parts could serve as resource reserves for these metals.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"115 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135806325","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel chalcone analogs derived from 4-(benzyloxy)benzaldehyde","authors":"Mihaela Balan-Porcăraşu, Gheorghe Roman","doi":"10.2478/auoc-2023-0015","DOIUrl":"https://doi.org/10.2478/auoc-2023-0015","url":null,"abstract":"Abstract Eight chalcone analogs were prepared through an aldol condensation starting from 4-(benzyloxy)benzaldehyde and either less common acetophenones or a few selected heteroaryl methyl ketones. The reaction has been performed through the classical approach that employs an alkali as catalyst for five chalcone analogs, while a variant that uses piperidine as basic catalyst was employed for the other three chalcone analogs. The structure of the resulting enones has been established by NMR spectroscopy. Photoinduced dimerization of a selected benzyloxy-substituted chalcone analog under irradiation with UV light for periods of time ranging from 30 minutes to 24 h has also been monitored using NMR spectroscopy. Analysis of the results demonstrated the presence of the E isomer of the chalcone analog along with three regioisomeric cyclobutanes in the irradiated sample.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"46 1","pages":"112 - 120"},"PeriodicalIF":0.9,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139365155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Eco-friendly and efficient monitoring of physico-chemical parameters of some mineral water from Slanic Moldova (Romania) during storage in different conditions – a case study","authors":"Lavinia Misaila, Narcis Barsan, Dumitra Raducanu, Luminita Grosu, Oana-Irina Patriciu, Irina-Claudia Alexa, Adriana-Luminita Finaru","doi":"10.2478/auoc-2023-0010","DOIUrl":"https://doi.org/10.2478/auoc-2023-0010","url":null,"abstract":"Abstract In this study, six natural mineral waters (from sources named 1bis, 5, 10, 14, 15, “Sonda 2”) with therapeutic potential from Slanic Moldova area (Romania) were assessed for physico-chemical parameters during storage in different conditions (bottled in PET or glass containers and kept at 20-22 °C or 4 °C) for a period of maximum 360 days. The main parameters investigated were pH, conductivity, total dissolved solids, salinity, as well as the major ions (Na + , K + , Ca 2+ , Mg 2+ , F − , Cl − , SO 4 2− , HCO 3 − ), using fast and environmentally friendly instrumental techniques (electrochemical and spectrometric / UV-Vis and ICP-MS). The physico-chemical indicators were measured at six time intervals (within 24 hours, after 7, 30, 90, 180 and 360 days) and the results obtained indicated that the pH variation was significant for the majority of samples kept at room temperature in PET containers (between 0.4 pH units - Spring 15 and over 2 pH units - springs 10, 14, 1bis and 5), while cold storage is most favorable for all natural mineral water samples. The monitoring of the chemical parameters determined during cold storage in glass containers did not reveal statistically significant variations and therefore it can be considered that these natural mineral waters are characterized by the stability of the chemical composition. For the entire analyzed period, the smallest variations of all twelve analyzed parameters were recorded for “Sonda 2”, in all storage conditions, followed by springs 1bis, 15, 14, 10 and 5 stored at 4 °C in glass containers.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135806328","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Xylopia aethiopica HPLC-DAD polyphenol profiling and antioxidant status from South-South region of Nigeria","authors":"J. Okpoghono, E. Osioma, Sandra Oghenekohwo Metie, Udoka Bessie Igue, Endurance Fegor Isoje, S. U. Okom","doi":"10.2478/auoc-2023-0014","DOIUrl":"https://doi.org/10.2478/auoc-2023-0014","url":null,"abstract":"Abstract To fill nutrient gaps, supplements are employed in the field of nutrition. The spice Xylopia aethiopica grows wild in many African countries and has been used as flavouring for soups. This study evaluates the polyphenols and antioxidant profile of different fractions of X. aethiopica methanol extract. Powdered sample of X. aethiopica (250 g) was suspended in methanol (1.5 litre) for 48 hours and the extract was concentrated at 45 °C using water bath to obtain methanol crude extract which was fractionated into n-hexane (n-Hex), chloroform (Chl), diethyl ether (DEE), n-butanol (n-Bu) and aqueous fractions using liquid- liquid partition separation technique. Antioxidant properties were investigated using standard methods and the polyphenols were estimated using high performance liquid chromatography with diodearray detector (HPLC-DAD). Results revealed that the DEE fraction had significantly (p < 0.05) high total phenol content (TPC), proanthocyanidins, anthocyanins, 1,1-diphenyl-2-picrylhidrazyl (DPPH) radical scavenging, ferric reducing antioxidant power (FRAP) and total antioxidant capacity (TAC) as compared with other fractions. The highest luteolin and taxifolin content was detected in n-Hex fraction. Polyphenols found in DEE fraction in the established HPLC-DAD assay were p-anisic acid (0.07 ng/g), caffeic acid (0.56 ng/g), vanillic acid (0.91 ng/g), salicylic acid (1.64 ng/g), gallic acid (3.09 ng/mL), ferulic acid (3.64 ng/g), p-coumaric acid (5.15 ng/g), sinapinic acid (6.63 ng/g) and protocatechuic acid (24.89 ng/g). The different fractions of X. aethiopica displayed various polyphenols potential with probable antioxidant activity, which may be useful in neutralizing free radicals and the treatment of chronic inflammatory associated metabolic ailments, such as obesity and diabetes.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"59 1","pages":"104 - 111"},"PeriodicalIF":0.9,"publicationDate":"2023-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139364929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unlocking the chemistry and properties of oil-containing sludge for potential utilization","authors":"S. Tang, Lin Zhi Lee, A. Arsad, Z. Zakaria, Muhammad Abbas Ahmad-Zaini","doi":"10.2478/auoc-2023-0005","DOIUrl":"https://doi.org/10.2478/auoc-2023-0005","url":null,"abstract":"Abstract At present, possible utilization of oil-containing sludge so as to achieve the sustainable environment has become a subject of considerable interest. The oleochemical factory generates nearly two metric tons of sludge per day from the effluent processing plant. Its disposal is costly and strenuous towards the environment, therefore different alternatives to handling and utilization were studied. The sludge and its derivatives were characterized for elemental composition, proximate analysis, ash and oil constituents, surface analysis, leaching tests and calorific value. Results show that the oil-containing sludge is rich in carbon, calcium, and iron. It has a high calorific value of 33.8 MJ/kg, that is partly attributed to the oil content of 68 %. These preliminary characteristics data offer insight into several promising applications of converting “trash” into “treasure” towards sustainable environment.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"102 1","pages":"28 - 33"},"PeriodicalIF":0.9,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84647923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Chemical coagulation and biological techniques for wastewater treatment","authors":"S. O. Akinnawo, P. O. Ayadi, M. Oluwalope","doi":"10.2478/auoc-2023-0003","DOIUrl":"https://doi.org/10.2478/auoc-2023-0003","url":null,"abstract":"Abstract This paper reports the effectiveness of chemical coagulation and biological techniques for the treatment of wastewater from industrial and agricultural operations. Agricultural husbandry has been reported to produce wastewater that has high content of chemical oxygen demand (COD), biological oxygen demand (BOD), turbidity as well as organic and inorganic pollutants. A comparison on the use of organic and inorganic based coagulants as well as the optimum conditions required for high percentage removal efficiency of pollutants from wastewater has been reviewed. At optimum experimental condition, ferric chloride coagulants were reported to yield 98, 95, 93 and 50 % removal of color, turbidity, iron and manganese. Moreover, chemical coagulation, electrocoagulation and biological methods have been reported to display a close range in their capacities for removing pollutants from wastewater. However, biological method was observed to be highly effective in the removal of pollutants from wastewater but requires more time and produces lesser volume of sludge, when compared to chemical method in the treatment of wastewater.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"60 1","pages":"14 - 21"},"PeriodicalIF":0.9,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79268841","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of the inhibitory action of essential oil from Eucalyptus globulus leaves on the corrosion of mild carbon steel in 1M HCl medium","authors":"Malick Bathily, B. Ngom, Malick Mbengue, D. Gassama","doi":"10.2478/auoc-2023-0001","DOIUrl":"https://doi.org/10.2478/auoc-2023-0001","url":null,"abstract":"Abstract The present work aims to valorize an aromatic and medicinal plant of Eucalyptus globulus found in the region of Dakar, Senegal. To do so, we first extracted the essential oil contained in the leaves of the plant harvested in October 2020. We obtained the essential oil by hydrodistillation using a Clevenger type extractor with a yield of 1.70% of the dry plant mass. This value is quite appreciable compared to the different values in the literature. The essential oil extracted from the leaves of Eucalyptus globulus was tested as a green inhibitor on carbon steel type XC38 in 1M HCl acid medium by the mass loss method. The results obtained led to a maximum inhibitory efficiency of 89.03% for a concentration of 1.6 g/L of essential oil at room temperature of 298 K. The effect of temperature on the inhibitory behavior of the essential oil was also studied over a range of 298 K to 338 K. In this temperature range, a loss of efficiency was observed with increasing temperature, reaching a value of 15.33% at 338 K. Thermodynamic quantities were then determined. The plot of the different isotherms showed that the adsorption of the essential oil obeys the Langmuir isotherm. The results obtained showed a physical character of adsorption of this essential oil.","PeriodicalId":19641,"journal":{"name":"Ovidius University Annals of Chemistry","volume":"42 1","pages":"1 - 7"},"PeriodicalIF":0.9,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79320104","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}