DCH18C6 using strontium extraction selectivity investigation and sequential soil fractionation study

85Sr as radioindicator has been applied to strontium separation selectivity study using cisdicyclohexano-18-crown-6 (DCH18C6) as extraction agent and picric acid as counter ion with the aim to contribute to the development of a rapid method of strontium extraction. The same radioindicator has been used for strontium fractionation study in chosen soils by application of Tessier- and BCR sequential extraction procedures. Experimental results have shown, that the mentioned extraction system is applicable for IDA determination of Sr2+ in ∼1000-fold abundance of Ca2+, ∼1000-fold abundance and Mg2+, ∼10-fold abundance of K+ and ∼0.2-fold abundance of Ba2+. For the soil samples - chernozems developed on loess - from the near vicinity of NPP Jaslovské Bohunice the exchangeable strontium fraction reached as much as 50 – 60 %.

Sequential extraction and risk assessment of pollutants from one major tributary of the Ganga

The geochemical fractionation of toxic heavy metals Cd, Pb, Cr, Co, Mn, Ni, Cu, Fe and Zn was investigated in 10 different sites of river bed sediments (up, mid and downstream) of Gomti River at Lucknow city. Sequential extraction technique was used to identify the distribution of trace elements binding in different fractions i.e., exchangeable, carbonate, Fe and Mn oxide, organic matter and residual. Heavy metal concentrations were least at upstream and significantly higher in mid and downstream. Fractionation indicated that dominant metals were bound in residual fraction to the bed sediments except for Cd and Pb which were bound in an equivalent fraction. Geo-accumulation index factor reveals that the enrichment of heavy metals in the bio-available fraction is contributed anthropogenically. Hierarchical cluster analysis also shows the metal pollution load in the river. Risk assessment code of Cd and Ni showed very high risk (ranged from 54.41 to 85.56 and 20.57 to 44.92 respectively) followed by Pb (high risk), Zn, Co (medium risk), Cr, Mn, Cu, Fe (low risk) in Gomti River water. Further, concentrations of Cd and Pb at mid Lucknow were 31 and 75%, high enough to pose a substantial risk to the environment.

Remediation of Smelter Contaminated Soil by Sequential Washing Using Biosurfactants

This paper presents experimental results from the use of biosurfactants in the remediation of a soil from a smelter in Poland. In the soil, concentrations of Cu (1659.1 mg/kg) and Pb (290.8 mg/kg) exceeded the limit values. Triple batch washing was tested as a soil treatment. Three main variants were used, each starting with a different plant-derived (saponin, S; tannic acid, T) or microbial (rhamnolipids, R) biosurfactant solution in the first washing, followed by 9 different sequences using combinations of the tested biosurfactants (27 in total). The efficiency of the washing was determined based on the concentration of metal removed after each washing (CR), the cumulative removal efficiency (Ecumulative) and metal stability (calculated as the reduced partition index, Ir, based on the metal fractions from BCR sequential extraction). The type of biosurfactant sequence influenced the CR values. The variants that began with S and R had the highest average Ecumulative for Cu and Pb, respectively. The Ecumulative value correlated very strongly (r > 0.8) with the stability of the residual metals in the soil. The average Ecumulative and stability of Cu were the highest, 87.4% and 0.40, respectively, with the S-S-S, S-S-T, S-S-R and S-R-T sequences. Lead removal and stability were the highest, 64–73% and 0.36–0.41, respectively, with the R-R-R, R-R-S, R-S-R and R-S-S sequences. Although the loss of biosurfactants was below 10% after each washing, sequential washing with biosurfactants enriched the soil with external organic carbon by an average of 27-fold (S-first variant), 24-fold (R first) or 19-fold (T first). With regard to environmental limit values, metal stability and organic carbon resources, sequential washing with different biosurfactants is a beneficial strategy for the remediation of smelter-contaminated soil with given properties.

Antioxidant Activity of Different Extracts from Black Alder (Alnus glutinosa) Bark with Greener Extraction Alternative

Phenolic compounds isolated from plant biomass consist of bioactive components showing a wide range of benefits for humans, including antioxidant, antimicrobial or anti-inflammatory effects. This paper presents the potential value of black alder (Alnus glutinosa (L.) Gaertn. (Betulaceae)) bark for the production of biologically active substances, despite its current use as a low value fuel source. Most of the extraction methods employ neat organic solvents to obtain extracts with a high antioxidant potential from biomass. The aim of this work is to show the advantages and disadvantages of the extraction process by taking into account the principles of ‘green chemistry’ and replacing the organic solvents with ‘green’ solvent water. Using the advantages of accelerated solvent extraction (ASE), it has been shown that the use of deionized water has the prospect of replacing organic solvents. In the case of the one-step water extraction, the total polyphenol content (TPC) varies from 0.55 to 0.62 Gallic acid equivalent (GAE) g/g in the extracts, depending on the temperature, whereas with the result of the sequential extraction with the organic solvents, the TPC content of the 40% (v:v) ethanol extracts ranges from 0.39 to 0.61 GAE g/g, depending on the temperature. The influence of the total polyphenol content and the total proanthocyanidin content on the antioxidant activity is shown. The antioxidant activity (IC50, mg/L) of the extracts obtained with the organic solvents in the (2,2-diphenyl-1-picrylhydrazyl) DPPH• test varies from 4.05 to 9.58, depending on the temperature in the range of 70–150 °C, respectively, while the results obtained with the deionized water showed promising results in the range of 6.33–7.36 in the temperature range of 70–150 °C, respectively. The extraction with the deionized water showed that approximately 90% of the substances in the extracts obtained with the organic solvents by sequential extraction are possible to obtain as deionized water extracts.

CHEMICAL COMPOSITION OF EXTRACTS OF GINSENG REAL ROOT (PANAX GINSENG) OBTAINED BY SEQUENTIAL EXTRACTION WITH DIFFERENT-POLAR SOLVENTS

Экстракцию корней женьшеня осуществляют водно-спиртовыми растворами или водой с последующим консервированием этиловым спиртом. При этом отмечается неполное извлечение биологически активных компонентов. Анализ химического состава корней женьшеня показал, что в них содержатся вещества различной полярности, поэтому целесообразно для лучшего извлечения экстрактивных веществ (ЭВ) проводить экстракцию этого лекарственного сырья в три этапа с использованием в качестве растворителей сжиженного диоксида углерода, этилового спирта и воды. Объектами исследования были экстракты, полученные из двух образцов измельченных корней женьшеня: из образца сырья 1 получены при последовательной экстракции СО2-экстракт из исходного сырья, спиртовой и водный экстракты; из образца сырья 2 – спиртовой экстракт из исходного сырья и водный экстракт из сырья, подвергнутого экстракции этиловым спиртом. Установлено, что последовательная экстракция сжиженным диоксидом углерода, этиловым спиртом и водой увеличивает выход ЭВ на 7% в сравнении с экстракцией только этиловым спиртом и водой. В составе СО2-экстракта корней женьшеня содержание токоферолов и других соединений фенольного ряда составляет 3,8%, каротиноидов 0,04%. Предварительная экстракция сжиженным диоксидом углерода корней женьшеня увеличивает выход органических кислот, флавоноидов и анионов солей в 5,8 раза; органических веществ, определенных методом ГЖХ, в 2,5 раза; моно-, ди- и полисахаридов в водном экстракте на 33,2% . В спиртовых экстрактах отмечено наибольшее содержание минеральных веществ: макроэлементов – магния, калия и фосфора; микроэлементов – марганца, железа, меди и йода. Общий выход сапонинов при последовательной экстракции корней женьшеня, включающей СО2-экстракцию, увеличивается на 9,7%. Результаты исследования подтверждают целесообразность разработки технологии комплексной переработки корней женьшеня, включающей применение в качестве растворителей сжиженного диоксида углерода, этилового спирта и воды. Extraction of ginseng roots is carried out with water-alcohol solutions or water, followed by preservation with ethyl alcohol. At the same time incomplete extraction of biologically active components is noted. Analysis of the chemical composition of ginseng roots shows that they contain substances of different polarities, so it is advisable to extract this medicinal raw material in three stages using liquefied carbon dioxide, ethyl alcohol and water as solvents for better extraction of extractive substances (ES). The objects of the study were extracts obtained from two samples of crushed ginseng roots: from a sample of raw materials 1, CO2-extract from the feedstock, alcohol and water extracts were obtained by sequential extraction; from a sample of raw materials 2 an alcohol extract from the feedstock and water aqueous extract from raw materials extracted with ethyl alcohol. It was found that sequential extraction with liquefied carbon dioxide, ethyl alcohol and water increases the ES yield by 7% in comparison with extraction with only ethyl alcohol and water. In the composition of the CO2-extract of ginseng roots, the content of tocopherols and other phenolic compounds is 3,8%, carotenoids 0,04%. Preliminary extraction of ginseng roots with liquefied carbon dioxide increases the yield of organic acids, flavonoids and anions of salts by 5,8 times; organic substances determined by the gas-liquid chromatography method by 2,5 times; mono-, di- and polysaccharides in an aqueous extract by 33,2%. The alcohol extracts have the highest content of minerals: macronutrients – magnesium, potassium and phosphorus; microelements – manganese, iron, copper and iodine. The total yield of saponins during sequential extraction of ginseng roots, including CO2-extraction, increases by 9,7%. The results of the study confirm the feasibility of developing a technology for complex processing of ginseng roots, including the use of liquefied carbon dioxide, ethyl alcohol and water as solvents.

Sequential Extraction of Hydroxytyrosol, Mannitol and Triterpenic Acids Using a Green Optimized Procedure Based on Ultrasound

Olive-derived biomasses contain bioactive compounds with health promoting effects as well as antioxidant and sweet-tasting properties. However, their sequential extraction has not been attained. In the present study, firstly antioxidants and mannitol were extracted from exhausted olive pomace (EOP) by an eco-friendly method, ultrasound-assisted water extraction (UAWE). The amplitude (20–80%), extraction time (2–18 min) and solid loading (2–15%, w/v) were evaluated according to a Box–Behnken experimental design. Using the response surface methodology, the optimal conditions for extraction were obtained: 80% amplitude, 11.5% solid loading and 16 min. It enabled the multi-response optimization of the total phenolic content (TPC) (40.04 mg/g EOP), hydroxytyrosol content (6.42 mg/g EOP), mannitol content (50.92 mg/g EOP) and antioxidant activity (ferric reducing power or FRAP, 50.95 mg/g EOP; ABTS, 100.64 mg/g EOP). Moreover, the phenolic profile of the extracts was determined by liquid chromatography-UV and mass spectrometry, identifying hydroxytyrosol as the main phenolic compound and other minor derivatives could be characterized. Scanning electron microscopy was used to analyze the morphological changes produced in the cellular structure of EOP after UAWE. In addition, the chemical composition of the extracted EOP solid was characterized for further valorization. Then, a second extraction step was performed in order to extract bioactive triterpenes from the latter solid. The triterpenes content in the extract was determined and the effect of the previous UAWE step on the triterpenes extraction was evaluated. In this case, the use of ultrasound enhanced the extraction of maslinic acid and oleanolic acid from pelletized EOP with no milling requirement. Overall, UAWE can be applied to obtain antioxidant compounds and mannitol as first extraction step from pelletized EOP while supporting the subsequent recovery of triterpenic acids.

The sequential REE (Rare Earth Elements) extraction of weathered crusts of granitoids from Sibolga, Indonesia

Indonesia needs a proven technology for REE extraction to build a national REE industry. Monazite that has been recovered from placer deposits at Bangka-Belitung areas is the most potential REE source. In the future, ion adsorption type will be another potential source of REE deposits. This paper describes the sequential REE extraction of the weathered crusts of granitoids from Sibolga using sequential extraction ICP-MS analysis is applied to determine bulk samples mineralogical compositions and REE content. The total REE (∑REE) content of weathered crusts of granitoids from Sibuluhan Sihaporas A ranges from 265 to 479 ppm, while the amount of ∑REE leached by sequential extraction range from 151 to 263 ppm, and the percentage of adsorbed ∑REE ranges from 55 to 74%. In comparison, Sibuluhan Sihaporas B ranges from 302 to 634 ppm, 82 to 198 ppm, and 28 to 44%, respectively. ∑REE content of weathered granitoids crusts from Sarudik ranges from 135 to 219 ppm, while that SREE leached by sequential extraction range from 21 to 82 ppm, and percentage of adsorbed ∑REE range from 11 to 50 %, while that Sibolga Julu ranges from 191 to 304 ppm, 111 to 138 ppm, and 27 to 44%.