Ekstrakcija masnog ulja i fenola iz semena crne slačice (Brassica Nigra L.) eutektičkim rastvaračima i etanoliza masnog ulja u prisustvu kalcijum-oksida

The DESs are prepared based on triethanolamine as an acceptor, and oxalic acid, glacial acetic acid, L-(+)- lactic acid, oleic acid, glycerol, ethylene glycol, propylene glycol, choline chloride or 1,3-dimethylurea, as a donor, in a molar ratio of 1:1 (with acids as donors) or 1:2 (with polyols or amides as donors). The prepared DESs were used to measure physical (density, viscosity, and electrical conductivity) and calculate thermodynamic properties (coefficient of thermal expansion, molar volume, lattice energy, and heat capacity) in the temperature range 293.15–363.15 K at a pressure of 101.3 kPa. The DESs based on polyols and lower carboxylic acids can be used in various chemical and industrial processes at low temperatures. In contrast, for the DES with oleic acid and 1,3-dimethylurea, it is recommended to use at temperatures above 313.15 K. An analysis of the influence of the selected DES, triethanolamine:glycerol (TEOA:G), on yield, physicochemical properties, fatty acid composition, and antioxidant activity of black mustard seed oil, obtained by maceration with trichloroethylene after the pretreatment with the TEOA:G DES and a mixture of trichloroethylene and the TEOA:G DES, was performed. The oil was recovered by cold pressing and maceration with n-hexane and trichloroethylene. The highest oil yield was obtained by the maceration of black mustard seeds with trichloroethylene (31.10 g/100 g), which required twice the volume of trichloroethylene compared to the volume used in the maceration of black mustard seeds after the pretreatment of seeds with the TEOA:G DES in which gave a similar oil yield (29.95±1.20 g/100 g). The oil obtained by the maceration in the presence of the TEOA:G DES has similar physicochemical properties and fatty acid composition but better antioxidant activity than oil obtained by cold pressing. Furthermore, the influence of the use of the DESs TEOA:G, triethanolamine:propylene glycol (TEOA:PEG) and choline chloride:urea (ChCl:U) (molar ratio 1:2) and their mixtures with 25% water or ethanol in the extraction of phenolic compounds from black mustard seeds on the yield of total extractable substances, total phenol content, total flavonoid content and the antioxidant activity of the obtained extracts, were analyzed and compared with the influence of ethanol application as the most commonly used solvent in the extraction of phenolic compounds from plants. Total phenol content and total flavonoid content ranged from 19.9±0.1–32.2±0.2 mg gallic acid equivalents (GAE)/g and 3.9±0.1–7.4±0.3 mg quercetin equivalents (QE)/g, respectively. Black mustard seed extracts obtained with the ChCl:U DES and the mixtures of the ChCl:U or TEOA:G DESs with 25% ethanol showed the best antioxidant activity (IC50 = 100 mg·cm-3). Syringic acid, ellagic acid, gallic acid, caffeic acid, kaftaric acid, kaempferol, rutin, apigenin, taxifolin, vitexin, and hyperoside were identified in the obtained extracts. Finally, the influence of the application of the TEOA:G, TEOA:PEG, triethanolamine:choline chloride (TEOA:ChCl), triethanolamine:1,3-dimethylurea (TEOA:DMU), triethanolamine:ethylene glicol (TEOA:EG), triethanolamine:oleic acid (TEOA:OLK), triethanolamine:menthol (TEOA:M, molar ratio 1:2), and triethanolamine:decanoic acid (TEOA:DEK, molar ratio 1:1) DESs on the heterogeneous alkaline catalyzed ethanolysis of cold-pressed black mustard oil was analyzed. The ethanolysis was performed under the following reaction conditions: temperature of 70 ºC, molar ratio ethanol:oil of 12:1, the DES amount of 20%, and the calcined CaO amount of 10%. Almost all applied triethanolamine-based DESs (TEOA:G, TEOA: PEG, TEOA:ChCl, TEOA:DMU, TEOA:M, and TEOA:DEK) accelerated ethanolysis and provided a high content of fatty acid ethyl esters (FAEE) (≥95.20±0.56%) after 15 min of reaction time compared to the control reaction (without the presence of DES) (23.38±2.8%). The most effective DES was TEOA:ChCl, in the presence of which an FAEE content of 98.46±0.7% was achieved in 1.5 min. At the same time, in the presence of the TEOA:PEG and TEOA:M DESs, an FAEE content higher than 91% was achieved. In the presence of all applied DESs, the final products' separation was faster than the separation after the control reaction. The fastest separation was achieved in the presence of the TEOA:M and TEOA:ChCl DESs (immediately after cessation of mixing and after 1 min, respectively). To evaluate the kinetic parameters of the ethanolysis of black mustard oil catalyzed by calcined CaO in the presence of the TEOA:ChCl DES, a model of the pseudo-first order irreversible reaction and a model of variable order of reaction in relation to triacylglycerols and autocatalytic behavior of ethanolysis reaction were used. The calculated values of the apparent rate constant for both applied models were 0,600–3,219 min-1 and 0,803–3,836 L·mol-1·min-1, respectively while the calculated values of the activation energy were 77.18 kJ/mol and 71.79 kJ/mol, respectively. The physicochemical properties of the obtained biodiesel were within the limit values prescribed by the quality standard (EN 14214 standard)

Benefits of inoculation with azotobacter in the growth and production of tomato and peppers

The aim of this research was to investigate the effects of Azotobacter chroococcum in tomato and pepper growth and production by using two types of inoculation - seed inoculation and seedling inoculation. The effect of inoculation was observed thirty days after sowing, thirty days after transplanting, and in the phase of technological maturity. The following were measured: height of the plants, dry matter of the plants and number and the weight of the fruits. Inoculation had a positive effect on these in both plants. With tomato, better results were achieved when seedlings were inoculated. With pepper, the length of the plant and the dry matter were greater with seedling inoculation, whereas the number and the weight of the fruits were greater with seed inoculation

Polymorphisms of the GSTT1 and GSTM1 genes in women of central Serbia: Absence of association with uterine myoma

Since glutathione S-transferase (GST) enzymes are involved in cellular protection, we aimed to determine the distribution of GSTT1 and GSTM1 null genotypes in women in central Serbia in order to assess the risk of development of uterine myoma. The study consisted of 34 clinically diagnosed uterine myoma patients and 35 healthy control women. Analyses of GST polymorphism were carried out by multiplex PCR. Our results showed no significant differences in the GSTT1 and GSTM1 null genotypes between the patients and controls. Using the GSTT1 positive/GSTM1 positive combination as reference, there was no statistically significant risk of uterine myoma with the combination of GSTT1 null and GSTM1 null genotypes. We conclude that polymorphism of both GSTT1 and GSTM1 genes, alone or in combination, did not present the main risk for uterine myoma in women from central Serbia.[Projekat Ministarstva nauke Republike Srbije, br. III41010 i br. ON 175103

Supplementary material for the article: Relić, D.; Héberger, K.; Sakan, S.; Škrbić, B.; Popović, A.; Đorđević, D. Ranking and Similarity of Conventional, Microwave and Ultrasound Element Sequential Extraction Methods. Chemosphere 2018, 198, 103–110. https://doi.org/10.1016/j.chemosphere.2017.12.200

Supplementary material for: [https://doi.org/10.1016/j.chemosphere.2017.12.200]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2109]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3250

Nonacosan-10-ol and n-Alkanes in Leaves of Pinus pinaster

In leaf cuticular wax of Pinus pinaster, content of nonacosan-10-ol is high (77.1% on average). n-Alkanes ranged from C18 to C35 with the most dominant C29 (24.8%). The carbon preference index (CPItotal) ranged from 3.1 to 5.6 (4.0 on average), while the average chain length (ACLtotal) ranged from 14.0 to 17.0 (14.8 on average). Long-chain n-alkanes (n-C25-35) strongly dominated (80.1%) over middle-chain (n-C21-24= 18.9%) and short-chain (n-C18-20= 0.9%) n-alkanes

Supplementary material for the article: Relić, D.; Héberger, K.; Sakan, S.; Škrbić, B.; Popović, A.; Đorđević, D. Ranking and Similarity of Conventional, Microwave and Ultrasound Element Sequential Extraction Methods. Chemosphere 2018, 198, 103–110. https://doi.org/10.1016/j.chemosphere.2017.12.200

Supplementary material for: [https://doi.org/10.1016/j.chemosphere.2017.12.200]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2109]Related to accepted version: [http://cherry.chem.bg.ac.rs/handle/123456789/3250

Nonacosan-10-ol and n-Alkanes in Needles of Pinus halepensis

In needle cuticular wax of Pinus halepensis, nonacosan-10-ol is high (77.08% on average). n-Alkanes ranged from C18 to C35 with the most dominant C27 and C29 (32.4% and 25.8%, respectively). The carbon preference index ranged from 3.2 to 5.4 (3.4 on average), while the average chain length ranged from 14.0 to 18.0 (17.2 on average). Long-chain n-alkanes strongly dominated (95.1%)

Heterogeno katalizovana etanoliza suncokretovog ulja u prisustvu polietilen glikola, etil acetata i dietil etra kao kosolvenata

A heterogeneous reaction process using propylene glycol (PEG), ethyl acetate and diethyl ether as cosolvents for the transesterification of sunflower oil with ethanol in the presence of calcium oxide as a catalyst has been developed. Significant results were obtained with propylene glycol as a cosolvent. Under determined reaction conditions (CaO concentration, based on the oil weight 1.3736 mol∙dm-3; temperature 70°C; and ethanol-to-oil molar ratio 12:1), the conversion of sunflower oil to fatty acid ethyl esters (FAEE) exceeded 98% after 120 min, which was 2 times faster than transesterification of sunflower oil without a cosolvent. After initially enhanced ethanolysis, after 180 min ethyl acetate and diethyl ether negatively influenced the reaction rate and the FAEE yield.U radu je opisana heterogena transesterifikacija suncokretovog ulja sa etanolom i kalcijum oksidom kao katalizatorom u prisustvu polietilen glikola (PEG), etil acetata i dietil etra kao kosolvenata. Najpovoljniji rezultati su dobijeni sa polietilen glikolom kao kosolventom gde je, pod određenim reakcionim uslovima (koncentracija CaO, računata u odnosu na masu ulja 1.3736 mol∙dm-3, temperatura 70°C i molarni odnos etanol:ulje 12:1), konverzija suncokretovog ulja u etil estre masnih kiselina (FAEE) dostigla vrednost od 98% nakon 120 minuta, što je 2 puta brže od transesterifikacije suncokretovog ulja bez prisustva kosolventa. Etil acetat i dietil etar poboljšavaju reakciju etanolize na početku, ali, kako reakcija napreduje, posle 180 minuta, njihovo prisustvo u reakcionoj smeši negativno utiče na brzinu reakcije i prinos etil estrara masnih kiselina (FAEE)

The physicochemical and thermodynamic properties of the choline chloride-based deep eutectic solvents

This paper reports the physicochemical (density, dynamic viscosity, electrical conductivity and refractive index) and the thermodynamic (thermal expansion coefficient, molecular volume, lattice energy and heat capacity) properties of several choline chloride (ChCl) based deep eutectic solvents (DESs), with 1:2 mole ratio, respectively:ChCl:propylene glycol, ChCl:1,3-dimethyl-urea and ChCl:thiourea, at atmospheric pressure as a function of temperature over the range of 293.15-363.15 K. Their properties were also compared with those of some already characterized ChCl-based DESs, namely ChCl:ethylene glycol, ChCl:glycerol and ChCl:urea (1:2 mole ratio). Density, viscosity and refractive index of all DESs decrease with the increasing temperature while the electrical conductivity increases. Viscosity and conductivity of the tested DESs were fitted by both Arrhenius-type and Vogel-Tamman-Fulcher equations. The changes of molar enthalpy, entropy and Gibbs energy of activation, determined using the Eyring theory, demonstrated the interactional factor as predominant over the structural factor for all DES systems. The fractional Walden rule, used to correlate molar conductivity and viscosity, showed an excellent linear behaviour. It was shown that ChCl:propylene glycol DES had properties similar to ChCl:ethylene glycol and ChCl:glycerol DESs. However, the properties (density, viscosity and electrical conductivity) of ChCl:1,3-dimethylurea and ChCl::thiourea DESs were inferior to those of the ChCl:urea DES

A novel carbon paste electrode based on nitrogen-doped hydrothermal carbon for electrochemical determination of carbendazim

In this work, a new carbon paste electrode, prepared from nitrogen-doped hydrothermal carbon (CHTCN) was applied for the electrochemical detection and determination of carbendazim fungicide. CHTCN samples with the nominal nitrogen content 0.05-0.5 wt. % in glucose precursor were prepared by simple, low-cost synthesis with the accompanying carbonization to 1273 K. The presence of nitrogen in CHTCN samples was confirmed by elemental analysis. Characterization of CHTCN as material for carbon paste electrode was achieved by cyclic voltammetry measurement of the Fe(CN)(6)(3-/4-) redox couple. The results showed that best electrochemical response was obtained from the sample with a nominal nitrogen concentration of 0.1 wt. % and with tricresyl phosphate as a binder. During the development of a differential pulse stripping voltammetric method for carbendazim determination applying new electrode, the following experimental parameters were studied: the sort and amount of binding liquid, the effect of pH, accumulation potential and accumulation time. Under optimal conditions, the electrode offered linearity in the wide concentration range from 25 to 490 ng cm(-3) and an estimated detection limit of 1.21 ng cm(-3). Moreover, the electrode showed good stability, high selectivity and satisfactory anti-interference ability. Finally, the developed method was successfully applied for the determination of carbendazim traces in spiked tap and river water samples