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Response surface methodology (RSM) was employed to optimize the process parameters of the supercritical carbon dioxide extraction of hop cones in terms of their antifungal properties against Fusarium culmorum and Aspergillus niger. The effects of temperature (40–50 °C), pressure (200–300 bar), and CO2 consumption (25–75 kgCO2/kg) on the extraction yield, content of α- and β-acids, as well as pathogens' growth inhibition were investigated. Both pressure and CO2 consumption had a significant effect on antifungal properties. It was observed that the best results for antifungal properties were obtained when hop cones were extracted with pure carbon dioxide at the temperature of 50 °C, under the pressure of 300 bar with CO2 consumption at the level of 75 kgCO2/kg of feed for extraction. The highest antifungal properties of hop cone supercritical carbon dioxide extracts were analyzed as 100% for Fusarium culmorum and 68% for Aspergillus niger, calculated as the growth inhibition of tested pathogens. The aim of the study was to determine the optimum values of extraction parameters to achieve the maximum response and enable us to investigate the interaction of these parameters on the antifungal properties of hop cone extracts. [ABSTRACT FROM AUTHOR]

In this study a multi-residue determination method for 36 pesticides in dried hops was reported. The sample preparation procedure was based on the acetate buffered QuEChERS method. A few mixtures of dispersive solid phase extraction (dSPE) sorbents consisting PSA, C18, GCB, Z-Sep and Z-Sep+ were investigated to clean-up the supernatant and minimize matrix co-extractives. The degree of clean-up was assessed by gravimetric measurements, which showed the best results for mixtures containing the Z-Sep+ sorbent. This is the first study to apply Z-Sep+ sorbent for hops material and the first to improve the method for pesticide residues determination in hops. Samples were analysed using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and the procedure was validated according to the SANTE/11813/2017 document at four concentration levels: 0.02, 0.05, 0.1 and 1 mg/kg. The limits of quantification (LOQ) were in the range of 0.02–0.1 mg/kg. For all active substances, the trueness (recovery) ranged from 70 to 120% and the precision (RSDr) value was <20%. Specificity, linearity and matrix effect were also evaluated. The validated method was applied to the analysis of 15 real dried hop samples and the relevant data on detected residues were included. [ABSTRACT FROM AUTHOR]

The complexes N[Et.sub.4][Fe(N[S.sub.3])(CNR)] (1), [Fe[{Fe(N[S.sub.3]) (CNR)}.sub.2]-S,S'] (2), [Co[{Fe(N[S.sub.3])(CNMe)}.sub.2]-S,S'] (3), and [Ni[{Fe(N[S.sub.3])(CNMe)}.sub.2]-S,S'] (4) (R = Me, t-Bu, or [C.sub.6][H.sub.11](Cy)) have been prepared and the X-ray crystal structures of N[Et.sub.4][Fe(N[S.sub.3])(CNMe)] (1a) and [Fe{[Fe (N[S.sub.3])(CNCy)}.sub.2]-S,S'] (2c) have been determined. Mossbauer and IR spectroscopic data and room temperature magnetic moments for these complexes are reported. Key words: iron, cobalt, nickel, thiolate, isocyanide.

The stabilization of the rare-earth metal alkyl and halide complexes by a cyclen-derived [NNNN] macrocyclic ancillary ligand is studied. The ligand is shown to act as a monoanionic ancillary environment during stabilization.

A series of co-precipitated cerium-promoted nickel-aluminum catalysts was prepared. The physicochemical properties of the precursors were analyzed by means of various methods including XRF, HT-XRD, TPR, surface area and thermal decomposition as well as porosity measurements. The activity and selectivity of the NiAlCe catalysts in the hydrogenation reaction of canola oil were investigated and the results compared to those for the cerium-free catalyst. Besides improving some physicochemical properties of the precursors, the addition of cerium significantly improved the cis/trans selectivity, yet at the expense of some loss of the activity in case of larger cerium loadings. Upon addition of a relatively low amount of cerium (0.67 wt%) the content of the C18:1 trans fraction decreased by ca. 35 %. Together with the synergistic effect of the hydrogen pressure a significant decrease of the C18:1 trans fraction by ca. 48 % could be achieved. Furthermore, compared to the cerium-free catalyst, the addition of cerium resulted in a slower drop of the C18:1 cis fraction and a slower increase of the C18:0 fraction in time during the hydrogenation process. [ABSTRACT FROM AUTHOR]

Canola oil was hydrogenated on an industrial nickel catalyst at 180 |C under a wide range of pressures from 1.5 to 21 bar(a). The effect of hydrogen pressure on the hydrogenation characteristics and fatty acids profile was investigated. The hydrogenation kinetics were described by a simplified three-step model including linolenic acid. The apparent rate constants for the particular reaction steps (hydrogenation, isomerization) kx as well as rate constants kx0 and reaction orders in hydrogen were determined. The results reveal that with the increasing pressure an increase of values of all rate constants was observed, with the largest increase being observed for the rate constant of hydrogenation of monoenes to stearic acid (about 20 times). Moreover, with the increasing pressure the isomerization rate of cis dienes to trans dienes was found to become lower than the dienes hydrogenation rate. Analogously, the cis/trans monoenes isomerization rate was also found to decrease with the increasing pressure. The reaction orders of the hydrogenation steps with respect to hydrogen were in the range of 0.35 to 1.1. The kinetic model was verified by comparsion of predicted fatty acids contents with the experimental data of fatty acids profiles. It emerged that a simplified kinetic model proposed can be utilized to simulate the course of the hydrogenation process and concentrations of fatty acids at a certain iodine value. [ABSTRACT FROM AUTHOR]

The effect of the CO 2 saturation time of the aqueous suspension of the raw, primary low-surface ZnO on material properties has been investigated. The materials have been investigated by means of the following techniques: XRD, TG/DTG coupled with MS, N 2 physical sorption and SEM. The results reveal platelet-like hydrozincite as a product of saturation, which undergoes thermal decomposition to ZnO of the similar morphology. The modification of ZnO through the CO 2 saturation results in essential changes of the morphology. During the subsequent thermal decomposition porous structure is created with a simultaneous drastic increase of the specific surface area. All these changes lead to the conversion of “common” zinc oxide into active zinc oxide. [ABSTRACT FROM AUTHOR]

The effect of the precursor ageing time on the structure, thermal decomposition, specific surface area, active copper surface area as well as on the morphology of the precursors and catalysts oxide forms was investigated. The hydroxycarbonate precursor, with the composition corresponding to industrial catalysts, was prepared via coprecipitation method from the solutions of copper and zinc nitrate with a mixture of sodium aluminate and sodium carbonate at pH = 7.4 and then aged in the mother liquor. The activity of the prepared catalysts in the LT-WGS reaction was compared under conditions similar to those in the industrial process. The results reveal that the precursor ageing influences the precursor phase composition, the active copper surface area and the catalytic activity. The activity decreases with the increasing ageing period but the activity concerned a single surface copper atom (TOF) is constant and independent of the ageing time. [ABSTRACT FROM AUTHOR]

Lavandula angustifolia is one of the most widely cultivated non-food crops used in the production of essential oil; it is used in perfumery, aromatherapy, pharmaceutical preparations, and food ingredients. In this study, supercritical fluid extraction (SFE) and molecular distillation (MD) were combined, primarily to enrich scCO2 extracts with lavender oxygenated monoterpenes, avoiding thermal degradation, hydrolysis, and solvent contamination, and maintaining the natural characteristics of the obtained oils. Molecular distillation was developed for the first time for the extraction of crucial lavender fragrance ingredients, i.e., from two scCO2 extracts obtained from dry flower stems of lavender cultivated in Poland and Bulgaria. The best results for high-quality distillates were obtained at 85 °C (EVT) and confirmed that linalyl acetate content increased from 51.54 mg/g (initial Bulgarian lavender extract, L-Bg-E) and 89.53 mg/g (initial Polish lavender extract, L-Pl-E) to 118.41 and 185.42 mg/g, respectively, corresponding to increases of 2.3 and 2.1 times in both distillate streams, respectively. The distillates, light oils, and extracts from lavender were also evaluated for their antimicrobial properties by determining the minimum inhibitory concentration (MIC) by the broth microdilution method. Generally, Gram-positive bacteria and Candida spp. were more sensitive to all distilled fractions and extracts than Escherichia coli (Gram-negative bacteria). [ABSTRACT FROM AUTHOR]

The iridium dinitrogen complex [IrCl(N2)(PPh3)2] (1) was found to react with alkynylsilanes RC≡CSiR'3 to form the vinylidene iridium(I) complexes trans-[IrCl{=C=CR(SiR'3)} (PPh3)2 (R/R′=Ph/Me, 2; Me/Me, 3; Bn/Me, 4; SiMe3/Me, 5; SiEt3/Et, 6; iPr/Me, 7) and with Me3SiC≡CC(O)R to yield the iridium η2-alkyne complexes trans-[IrCl{η2-Me3SiC≡CC(O)R}(PPh3)2] (R=OEt, 9; Me, 11). Complex 9 was found to isomerize upon heating or upon UV irradiation yielding the vinylidene complex trans-[IrCl{=C=C(SiMe3)CO2Et}(PPh3)2] (10). The reaction of 1 with Me3SiC≡C—C≡CSiMe3 yielded the complex trans-[IrCl{=C=C(SiMe3)C≡CSiMe3}(PPh3)2] (8), whereas with MeO2CC≡CCO2Me the iridacyclopentadiene complex [Ir{C4(CO2Me)4}Cl(PPh3)2] (13) was formed. The complexes were characterized by means of 1H, 13C and 31P NMR spectroscopy as well as by IR spectroscopy and microanalysis. [Copyright &y& Elsevier]

The complexes NEt[sub 4] [Fe(NS[sub 3] )(CNR)] (1), [Fe{Fe(NS[sub 3] )(CNR)}[sub 2] -S,S' ] (2), [Co{Fe(NS[sub 3] )(CNMe)}[sub 2] -S,S' ] (3), and [Ni{Fe(NS[sub 3] )(CNMe)}[sub 2] -S,S' ] (4) (R = Me, t-Bu, or C[sub 6] H[sub 11] (Cy)) have been prepared and the X-ray crystal structures of NEt[sub 4] [Fe(NS[sub 3] )(CNMe)] (1a) and [Fe{Fe(NS[sub 3] )(CNCy)}[sub 2] -S,S' ] (2c) have been determined. Mössbauer and IR spectroscopic data and room temperature magnetic moments for these complexes are reported.Key words: iron, cobalt, nickel, thiolate, isocyanide.On a préparé les complexes de NEt[sub 4] [Fe(NS[sub 3] )(CNR)] (1), [Fe{Fe(NS[sub 3] )(CNR)}[sub 2] -S,S' ] (2), [Co{Fe(NS[sub 3] )(CNMe)}[sub 2] -S,S' ] (3) et [Ni{Fe(NS[sub 3] )(CNMe)}[sub 2] -S,S' ] (4) (R = Me, t-Bu ou C[sub 6] H[sub 11] (Cy)) et on a déterminé les structures de NEt[sub 4] [Fe(NS[sub 3] )(CNMe)] (1a) et de [Fe{Fe(NS[sub 3] )(CNCy)}[sub 2] -S,S' ] (2c) par diffraction des rayons X. Pour chacun de ces complexes, on a déterminé les spectres de Mössbauer et IR ainsi que les moments magnétiques à la température ambiante.Mots clés : fer, cobalt, nickel, thiolate, isocyanure.[Traduit par la Rédaction] [ABSTRACT FROM AUTHOR]

In this study, potential antifungal properties of a brown alga Fucus vesiculosus were evaluated. The algal extract was obtained with the use of supercritical fluid extraction (scCO2) at a temperature of 50 °C under a pressure of 300 bar. The aqueous solution of the extract at the concentration of 0.05%, 0.2%, 0.5% and 1.0% was studied against pathogenic fungi on a liquid RB medium. This study is the first report on antifungal properties of the brown algae F. vesiculosus scCO2 extract against Fusarium culmorum and Fusarium oxysporum phytopathogens. The concentrations of the studied extract (0.5% and 1.0%) were demonstrated to have an ability to inhibit 100% growth of macroconidia within 144 h, as well as an ability to cause their total degradation. As a result of the study, the antifungal effect of fucosterol against F.culmorum was also indicated. The total macroconidia growth was inhibited by 1.0% fucosterol. Moreover, at lower concentrations (0.05–0.2%) of fucosterol, macroconidia were characterized by shorter length and structural degradation was observed. The mycelial growth of Fusarium oxysporum (Fo38) by 1% scCO2F. vesiculosus extract was analyzed at the level of 48% after 168 h of incubation, whereas 100% extract was found to be effective in F. culmorum (CBS122) and F. oxysporum (Fo38) growth inhibition by 72% and 75%, respectively after 168 h of incubation. [ABSTRACT FROM AUTHOR]

Due to their numerous health benefits associated with various diseases and anti-oxidation properties, the phenolic compounds collectively referred to as phytochemicals have attracted a lot of interest, however, a single extraction method for polyphenols has not been developed yet. Supercritical fluid extraction, a green extraction method, provides the final product without organic solvent residues. In this work the extraction of lavender was performed using supercritical carbon dioxide. A statistical experimental design based on the Box-Behnken (B-B) method was planned, and the extraction yields and total phenolic contents were measured for three different variables: pressure, temperature and extraction time. The ranges were 200–300 bar, 40–60 °C and 15–45 min. The extracts yields from scCO2 extraction were in the range of 4.3–9.2 wt.%. The highest yield (9.2 wt.%) was achieved at a temperature of 60 °C under the pressure of 250 bar after 45 min. It also corresponded to the highest total phenolic content (10.17 mg GAE/g extract). Based on the study, the statistically generated optimal extraction conditions to obtain the highest total phenolic compounds concentration from flowers of Lavandula angustifolia were a temperature of 54.5 °C, pressure of 297.9 bar, and the time of 45 min. Based on the scavenging activity percentage (AA%) of scCO2 extracts, it is concluded that the increase of extraction pressure had a positive influence on the increase of AA% values. [ABSTRACT FROM AUTHOR]

Two different extraction methods were used for a comparative study of essential oils obtained from the Humulus lupulus scCO2 (sc-supercritical) extract: microwave-assisted hydrodistillation (MAHD) and conventional hydrodistillation (HD). As a result, the best conditions for the maximum essential oil production were determined for the MAHD method at 335 W microwave power for 30 min at water to raw material ratio of 8:3. The obtained essential oils were enriched in β-myrcene in the amount of 74.13%–89.32% (wt%). Moreover, the first application for determination of the above-mentioned volatile compounds by supercritical fluid chromatography (SFC) with photo-diode array detection (PDA) is presented, which in comparison with gas chromatography coupled with mass spectrometry (GC-MS/MS) resulted in similar values for β-myrcene and α-humulene in obtained samples within less than 1 min. [ABSTRACT FROM AUTHOR]

The separation of phenolic compounds by supercritical fluid extraction has been widely studied throughout the last two decades. This is evidenced by a number of publications and articles. Supercritical fluid extraction (SFE) has become thus the effective method of separating the mentioned group of compounds. On the other hand, SFE is a beneficial approach in plant waste materials utilization and reduction of environmental burdens caused by the wastes. The aim of the study is to gather and systematize available information on the phenolic compounds separation that have been reported so far as well as to evaluate whether there is one optimal supercritical fluid extraction method for the phenolic compounds. [ABSTRACT FROM AUTHOR]

The effect of steam gasification on the surface composition, surface area, pore size distribution as well as on the morphology of the carbon supports has been investigated. Materials have been characterized by nitrogen physisorption, mercury porosimetry, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). Model samples of the Co–Mo–K catalysts with the same composition have been prepared on carbon supports differing in the temperature of steam gasification process. Catalytic activity measurements have been carried out in a gradientless reactor in a kinetic regime at low partial pressures of reagents. A relationship between textural parameters of the supports and the catalysts activity has been estimated. The highest activity in the SGS process has been determined for the Co–Mo–K/SRO/40.49 supported catalyst. [ABSTRACT FROM AUTHOR]

Abstract: The effects of cesium doping (in the concentration range up to 5wt.% Cs2O) introduced into a copper catalyst with the composition corresponding to that for the industrial catalysts used for low-temperature water–gas shift process (LT-WGS) have been investigated. Precursors and catalysts have been characterized by XRD, ICP-OS, TPD-EGA, N2O chemisorption, TPR, N2 physisorption and reaction rates for WGS and methanol synthesis under the pressure of 2.5MPa have been determined. The results reveal that the cesium doping inhibits radically methanol synthesis, with the optimal Cs2O content being <1wt.%. [Copyright &y& Elsevier]

The present study was focused on improving the supercritical fluid extraction process dedicated to the recovery of highly valuable extract from Silybum marianum seeds. At first, the process was tested using supercritical CO 2 at temperatures of 40 and 80 °C and pressures ranging from 100 to 300 bar. Obtained values were described using two literature models with acceptable agreement of experimental and calculated data. Further, the effect of the equipment design and process scale-up was investigated in four high-pressure units having volumes in the range from 280 mL to 40 L resulting in extraction yields up to 26 %. Based on the values of the parameters determined at the laboratory scale, the extraction process was successfully transferred to a semi-industrial scale. Finally, estimated costs for supercritical extract production in Poland for the year 2021 using a 1000 L high-pressure unit amounted to the price of 35.9 EUR per kg of extract. [Display omitted] • Kinetic of the SFE process significantly differs for four units having volumes from 0.28 to 40 L. • Three lab-scale units showed variation in extraction yield from 11.9 % to 18.0 %. • Sovova's model can be used for description the presented SFE process phenomenology. • Scale-up study showed a good agreement between laboratory and semi-industrial scale unit. • Economic evaluation indicated optimal industrial process of 3 h and extract cost of 35.9 EUR/kg. [ABSTRACT FROM AUTHOR]

Abstract: The Fe2O3-based catalysts have numerous advantages for HT-deN2O process applications. The possibility of enhancing their activity by various metal oxide modifiers addition (Al, Zr, Ce, La, Cu, Cr) has been investigated. The catalysts were prepared by the coprecipitation method and their physicochemical properties were characterized by N2 sorption, XRF and XRD methods. A quartz gradientless reactor was used for activity evaluation at the temperature range of 500–900°C. The modifiers efficiency was compared and the activity of hematite catalysts at 800̊C was found to increase in the following order: Cr

Lutetium alkyl complexes [Lu(L)(CH(2)SiMe(3))(THF)(n)], which contain a sulfur-linked bis(phenolato) ligand such as 2,2'-thiobis(6-tert-butyl-4-methylphenolate) (L=tbmp, 1) or 1,4-dithiabutanediyl-bis(6-tert-butyl-4-methylphenolate) (L=etbmp, 2), were isolated from the reaction of the lutetium tris(alkyl) complex [Lu(CH(2)SiMe(3))(3)(THF)(2)] with H(2)L. The monomeric structures of these complexes were confirmed by X-ray diffraction studies, showing distorted octahedral geometry around the metal centre. The reaction of [Lu(tbmp)(CH(2)SiMe(3))(THF)(2)] (1) with alcohols ROH (R=iPr, CHPh(2), CPh(3)) results in the formation of the corresponding alkoxide complexes [Lu(tbmp)(OR)(THF)(n)] (4-6). With PhSiH(3) hydride complexes [Lu(L)(mu-H)(THF)(n)](2) (L=tbmp, 7; etbmp, 8) have been prepared in moderate to good yields. They adopt a dimeric form in the solid state as revealed by the X-ray crystal structure of 7. The reactivity of the hydride complexes and their catalytic activity in the ring-opening polymerisation of L-lactide and the hydrosilylation of alkenes are also discussed.