Ethyl acetate: a possible alternative for anaesthetizing insects

A procedure previously used for sex steroids was adapted to extract free cortisol and cortisone from water samples taken from rainbow trout Oncorhynchus mykiss tanks. Both corticosteroids could be readily detected by radioimmunoassay (RIA), with cortisol being predominant. All stages of the sampling, extraction and RIA procedure were validated for cortisol. An intermittent problem with poor replication was traced to the use of diethyl ether during the extraction procedure, and was overcome by the use of ethyl acetate. Other modifications were also introduced to speed up the procedure. The concentration and time course of release of both corticosteroids were shown to be related to the degree of stress that the fish had been subjected to. It was confirmed that cortisol concentrations in water and estimated cortisol release rates increased in response to handling stress, and that both were correlated with plasma cortisol concentrations. The potential for using water cortisol concentration and release rates to assess the primary stress response of fishes as a non‐invasive alternative to blood sampling is discussed.

Vinylferrocene-terminated Si(111) was prepared by illuminating visible light onto a hydrogen-terminated Si(111) surface that was immersed in either diethyl ether-vinylferrocene or dibutyl ether-vinylferrocene solution. The use of either diethyl ether or dibutyl ether as grafting medium yielded a neutral ferrocenyl monolayer that was electrically connected with the silicon substrate. Both preparation media produce samples that have good electrochemical characteristics e.g., low peak potential separation and linear plot of peak current density with scan rate. The use of dibutyl ether as grafting solution resulted to a fast grafting rate, in which the optimum grafting time for samples with n-type and p-type substrates were 0.5 h and 1 h, respectively. Meanwhile, the use of diethyl ether resulted to the presence of lumps of deposited materials on the grafted surface. Nevertheless, even if these materials may be considered as impurities, these did not distort significantly the electrochemical characteristics of the sample.

Ethyl acetate and diethyl ether were compared for their ability to recover Ascaris spp. and Trichuris spp. eggs from seeded milorganite, liquid sludge, and cabbage. Concentrations of 10, 100, and 1000 eggs/10 g test sample were prepared for 20 replicates of each product. The use of diethyl ether yielded fewer eggs/10 g than did ethyl acetate in 5 of 6 sets of data. For Ascaris spp., recovery from cabbage was 10 times higher with ethyl acetate at the higher concentration than with diethyl ether. For Trichuris spp., recovery from liquid sludge was slightly higher with diethyl ether for all egg concentrations. The other results ranged from 0 to 23% difference in recovery for the 2 agents. Depending on the parasites in question and the products to be screened, the substitution of ethyl acetate for diethyl ether may be significant.

We examined stool specimens freshly collected from 202 Saudi Arabian military trainees with suspected high rates of intestinal parasitism. Specimens were processed in equal, 5-g portions by both the Merthiolate Iodine Formalin (MIF) and Formalin Ether (FE) techniques (Ritchie, 1948, Bull. U.S. Army Med. Dept. 8: 326). Permanently stained slides were not prepared. The prevalence of parasites and commensals is shown in Table I. We found 66.8% and 82.7% positive specimens by the MIF and FE techniques, respectively. Statistically significant differences between the two techniques in demonstration of parasites was observed only for Entamoeba coli, Endolimax nana, and Iodamoeba biitschlii. For the flagellates and cestodes, only Giardia lamblia and Hymenolepis nana were present in numbers sufficient for analysis by the matched pairs statistical test. The FE test was more efficient in both instances. These data have led us to continue using the FE technique in spite of the disadvantages occasioned by the use of diethyl ether. The zinc flotation alternative has likewise been found to be inferior to the FE technique for certain parasites (Bartlett et al., 1978, J. Clin. Micro. 7: 524-528). Ethyl acetate may be considered as a substitute for ether in the FE technique (Young et al., 1979, J. Clin. Micro. 10: 852), but it is also a flammable liquid but less so, and may eventually replace diethyl ether. The occurrence of high rates of intestinal parasitism in immigrant populations, foreign students and foreign military trainees may have important clinical management and public health implications. We advocate the qualitative and quantitative assessment of parasitism in these groups by routine stool surveys.

One hundred fecal specimens preserved in polyvinyl alcohol fixative were examined by the Formalin-ether sedimentation technique with ethyl acetate substituted for diethyl ether. Technical performance of the procedures, appearance and amount of sediment obtained, and organism morphology were comparable. Also, ethyl acetate is less flammable and, therefore, less dangerous to use than diethyl ether. Results of parasite recovery when diethyl ether or ethyl acetate was used revealed few clinical relevant differences, most of which could also have been attributed to other variables inherent in this type of diagnostic testing.

The aim of this study is to investigate the effect of ethyl acetate added to the solution used in nanofiber production and the changes in nanofiber diameters depending on the amount of ethyl acetate used. Solutions were prepared using polyacrylonitrile, high-entropy oxide, and dimethylformamide, and ethyl acetate was added to these solutions at ratios of 5%, 10%, and 15% relative to DMF. These solutions were fed into an electrospinning device to produce nanofibers. Nanofibers obtained from the solution containing 15% ethyl acetate exhibited a discontinuous and irregular morphology. However, in the solution containing 10% ethyl acetate, continuous nanofiber formation was achieved under production conditions of 0.14 ml/h feed rate, 6 kV voltage, 205 mm distance, and 500 rpm rotation speed, resulting in nanofiber diameters as small as 110 nm. The use of ethyl acetate at 5% and 10% ratios led to the formation of thinner and more homogeneous nanofibers, while the use of 15% ethyl acetate negatively affected nanofiber morphology by reducing solution viscosity. Solutions containing 5% PAN, 35% high-entropy oxide, and 10% ethyl acetate were processed using 16G (1.6 mm) and 22G (0.7 mm) nozzle diameters to produce nanofibers. The scanning electron microscope images of the obtained nanofibers revealed fiber diameters of 182 nm and 111 nm, respectively. X-ray diffraction patterns of the nanofibers indicated no significant changes in diffraction patterns with increasing ethyl acetate content. Fourier - transform infrared spectroscopy analyses conducted to examine the chemical structure of the nanofibers identified characteristic peaks corresponding to high-entropy oxides.

Simple alkyl esters as skin permeation enhancers

Potential of ethyl acetate in the determination of extractable organic halogens (EOX) from contaminated soil, sediment, and sewage sludge

Gas chromatography–mass spectrometry (GC-MS) is useful for the quantitative determination of the polyamines spermidine (SPD) and putrescine (PUT) and of the biogenic amine agmatine (AGM) in biological samples after derivatization. This GC-MS method involves a two-step extraction with n-butanol and hydrochloric acid, derivatization with pentafluoropropionic anhydride (PFPA) in ethyl acetate, and extraction of the pentafluoropropionic (PFP) derivatives by toluene of SPD, PUT, and AGM. We wanted to extend this GC-MS method for the biogenic amine histamine (HA), but we faced serious problems that did not allow reliable quantitative analysis of HA. In the present work, we addressed this issue and investigated the derivatization of HA and the effects of toluene and ethyl acetate, two commonly used water-insoluble organic solvents in GC-MS, and oven temperature program. Derivatization of unlabelled HA (d0-HA) and deuterium-labelled HA (d4-HA) with PFPA in ethyl acetate (PFPA-EA, 1:4, v/v; 30 min, 65 °C) resulted in the formation of d0-HA-(PFP)2 and d4-HA-(PFP)2 derivatives. d4-HA and 13C4-SPD were used as internal standards for the amines after standardization. Considerable quantitative effects of toluene and ethyl acetate were observed. The starting GC column temperature was also found to influence considerably the GC-MS analysis of HA. Our study shows the simultaneous quantitative analysis of HA as HA-(PFP)2, AGM as AGM-(PFP)3, PUT as PUT-(PFP)2, and SPD as SPD-(PFP)3 derivatives requires the use of ethyl acetate for their extraction and injection into the GC-MS apparatus and a starting GC column temperature of 40 °C instead of 70 °C. The PFP derivatives of HA, AGM, PUT, and SPD were found to be stable in ethyl acetate for several hours at room temperature. Analytically satisfactory linearity, precision, and accuracy were observed for HA, AGM, PUT, and SPD in biologically relevant ranges (0 to 700 pmol). The limits of detection of AGM, PUT, and SPD were about two times lower in ethyl acetate compared to toluene (range, 1–22 fmol). The limits of detection were 1670 fmol for d0-HA and 557 fmol for d4-HA. Despite the improvements achieved in the study for HA, its analysis by GC-MS as a PFP derivative is challenging and less efficient than that of PUT, AGM, and SPD.

In this work, the effect of ethyl acetate as a co-solvent is investigated on the low-temperature performance of the lithium-ion battery. The cyclic voltammetry measurements show that the solid electrolyte interface formation as a result of the reduction of ethyl acetate occurs in 2.15 V on the graphite surface which is higher than that of electrolyte without ethyl acetate in 1.97 V. Addition of ethyl acetate to electrolyte decreases the charge transfer resistance and also the total resistance of lithium-ion battery. The scanning electron microscopy images show that the morphologies of layers formed by reduction of electrolytes without and with ethyl acetate at room temperature are different due to the facile reduction of ethyl acetate. At 25 °C, the capacity retentions of the 18650-type graphite/LiCo1/3Ni1/3Mn1/3O2 (NMC111) full-cells without and with ethyl acetate are 96.84% and 93.16% after 50 cycles, respectively, compared to their initial discharge capacities. At − 40 °C, the cell without ethyl acetate cannot operate due to the electrolyte freezing while the cell containing ethyl acetate shows the 59.33% capacity retention compared to its discharge capacity at room temperature.

The medicinal plant-derived bioactive compounds have a potential for many biological activities, including antimicrobial activity. Artemisia cina is a medicinal plant from the Compositae family with the potential of having antitumor, antifungal, and antibacterial activity. This study aimed to determine the antibacterial activity and the flavonoid content of A. Cina’s ethyl acetate extract. Plants samples were extracted by ethyl acetate maceration method. Antibacterial activity was tested against Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) and Gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) by a disk diffusion method using 25, 50, and 100 mg/l extract concentrations. The flavonoid contents (quercetin and kaempferol) were measured using High-Performance Liquid Chromatography. The extracts of diploid and polyploid A. cina displayed some antibacterial activity, with the Gram-negative bacteria being more resistant than the Gram-positive counterpart. However, no significant difference was observed between the diploid and polyploid extracts. As for the flavonoid content, the highest quercetin content (0.5501 mg/ml) was found in the polyploid A. cina (J), while the highest kaempferol content (0.5818 mg/ml) was observed in the diploid A. cina (KJT). Although A. cina is widely grown in Indonesia, compared to other Artemisia species, A. cina has not been widely studied, especially its antibacterial potential and in related to its flavonoid content and the use of ethyl acetate as the extraction solvent.  This study reveals the potential of A. cina as a natural antibacterial agent.Â

Transphosphatidylation reaction of phosphatidylcholine to 4-methoxyphenol in water-immiscible organic solvents with immobilized phospholipase D

This study was compiled from the results of various researches performed on using diethyl ether as a fuel or fuel additive in dieselengines. Three different methods have been used the reduction of the harmful exhaust emissions of diesel engines. The first techniquefor the reduction of harmful emissions has improved the combustion by modification of engine design and fuel injection system, butthis process is expensive and time-consuming. The second technique is the using various exhaust gas devices like catalytic converterand diesel particulate filter. However, the use of these devices affects negatively diesel engine performance. The final technique toreduce emissions and improve diesel engine performance is the use of various alternative fuels or fuel additives. The major pollutantsof internal combustion engines are carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), particulate matter (PM) andsmoke. The most researches declare that the best way to reduce is the use of various alternative fuels i.e. natural gas, biogas, biodieselor using additives with alternative fuels or conventional fuels. Therefore, it is very important that the results of various studies onalternative fuels or fuel additives are evaluated together to practical applications. Especially, this study focuses on the use of diethylether in diesel engines as fuel or fuel additive in various diesel engine fuels. This review study investigates the effects of diethyl etheradditive on the HC emissions.

Impact of oxygenated additives to palm and jatropha biodiesel blends in the context of performance and emissions characteristics of a light-duty diesel engine

The low temperature combustion mode of homogeneous charge compression ignition eliminates particulate matter and oxides of nitrogen (NO x) emissions trade-off that prevails in high-temperature, diffusion-controlled conventional diesel combustion (CDC). In the present research, the significant challenge of narrow operating load range that hinders the commercial implementation of light-duty HCCI engines was overcome by employing ethyl acetate-gasoline blends. The gasoline concentration in test fuels was reduced in 10% decrements, from 84% to 24%, to replace it with ethyl acetate. The use of ethyl acetate, a renewable fuel, can help solve the energy crisis due to the rapid depletion of fossil fuels. An ignition improver was blended in the test fuels in a predetermined amount of 6% so that combustion stability was not hampered at lower loads. Parametric investigations were conducted to study the effect of progressively increasing ethyl acetate in test fuels on HCCI combustion, performance, and emissions. The machine learning tool of artificial neural network was implemented to learn the behavior of the test engine, considering load and fuel composition as input variables. The feedforward artificial neural network models were developed to predict the start of combustion, combustion phasing, indicated thermal efficiency, and emissions of carbon monoxide, soot, NO x, and unburned hydrocarbon (HC). A multi-objective optimization was performed to arrive at the best operating condition by integrating artificial neural network models with the genetic algorithm. All the developed artificial neural network models could predict responses with acceptable accuracy. The genetic algorithm indicated that the optimum point of the operation was at 80% load and 65% ethyl acetate in the test fuels. Experiments were conducted to validate the optimal HCCI conditions that resulted in 27% higher indicated thermal efficiency, 54% lower HC+NOx, and 99% lower soot emissions than CDC. Overall, the present study demonstrated the benefits of considering ethyl acetate as a fuel to improve HCCI engine metrics of off-road diesel engines.