Solvent Extraction Conditions Research Articles

OPTIMIZATION OF PHENOLIC COMPOUNDS EXTRACTION FROM PURPLE BASIL LEAF BY CONVENTIONAL AND MICROWAVE ASSISTED EXTRACTION METHOD

The present study aimed to determine the optimum extraction conditions of conventional solvent extraction (CSE) and microwave-assisted extraction (MAE) techniques to obtain maximum total phenolic (TPC), total flavonoid (TFC), total anthocyanin (TAC) and antioxidant capacity (AA). Response surface methodology (RSM) and central composite design (CCD) were used to determine optimum points of CSE and MAE. Both two extraction methods, all parameters significantly affected TPC, AA, TFC and TAC (p<0.05). MAE showed higher bioactive compounds yield than that of CSE. Optimum point for CSE and MAE was found to be 60°C and 30 min and 591.83 W and 2.98 min respectively. TPC, AA, TFC and TAC were obtained as 33.81mg/g, 160.27 mg/g, 11.89 mg/g and 331.01 mg/kg for CSE and 62.99 mg/g, 214.62 mg/g, 21.80 mg/g and 3462.93 mg/kg for MAE respectively. This study recommended that the MAE should be used for the extraction of PBL to increase phenolic extraction yield.

Optimized Extraction Method for Kleeb Bua Daeng Formula with the Aid of the Experimental Design

Kleeb Bua Daeng formula is one of the popular remedies sold in Chao Phya Abhaibhubejhr Hospital, Thailand. This formula contains Piper nigrum L., Nelumbo nucifera Gaertn., and Centella asiatica L. as active components. Owing to getting the highest content of its phytochemical compounds, the conditions of solvent extraction for this formula were optimized. The type of solvent, number of extraction times, and ratio between the material and solvent were varied in this study using the Box–Behnken design. The important phytochemical constituents (total phenolics, flavonoids, carotenoids, and anthocyanins) were also determined. From the result of this study, it was found that the highest content of each total active compound was obtained from different conditions such as the optimal extraction condition of phenolic content was obtained using methanol as solvent, one time of extraction, and the ratio of powder and solvent was 1 : 6. Thus, the variation of solvent extraction condition could affect the phytochemical content. Further studies about the herbal formula involving the extraction process should concern the variation of extraction conditions to get the highest content of the active compound.

Microscale extraction combined with gas chromatography/mass spectrometry for the simultaneous determination of polycyclic aromatic hydrocarbons and polycyclic aromatic sulfur heterocycles in marine sediments

This paper describes a novel method based on an ultrasound-assisted extraction microscale device (UAE-MSD) for the rapid and simultaneous determination of polycyclic aromatic hydrocarbons (PAH) and polycyclic aromatic sulfur heterocycles (PASH) in marine sediments. Solvent extraction conditions were optimized by applying a simplex-centroid mixture design. Optimum conditions were used to validate and determine the concentrations of 17 PAH and 7 PASH. The best conditions were obtained by extracting sediments with 500 µL of DCM:MeOH (65:35, v:v) over 23 min of sonication. Analytes were determined by gas chromatography/mass spectrometry in selective ion monitoring (GC-MS/SIM). Matrix effects were evaluated, and matrix-matched calibration was used for quantitation. Analytical method validation was carried out using the certified reference material NIST SRM 1941b, as well as sediment spiked with PASH at three concentration levels. Recoveries ranged between 70.0 ± 3.5% and 119 ± 9.1% for PAH and 80.6 ± 10.4% and 120 ± 10% for PASH. Linearity (R2) was ≥0.99 for all compounds. Method detection limits ranged from 8.8 to 30.2 ng g−1, while limits of quantification ranged from 29.4 to 1011 ng g−1. UAE-MSD was applied to marine sediments exposed to different anthropogenic impacts collected in Todos os Santos Bay, Brazil. PAH concentrations ranged from <LOQ to 667 ng g−1, while PASH levels were <LOQ to 1152 ng g−1. Dibenzothiophene was the compound presented in the highest concentration in all samples, with values up to 249 ng g−1. The results indicated contributions of pyrogenic sources from all compounds. The developed method can potentially be applied to extract trace levels of compounds in different solid matrices to minimize extraction time and solvent consumption.

Recovery of indium from jarosite residues of zinc refinery by a hydrometallurgical process

Indium is a strategic element essential in technological development; its recovery from jarosite produced as waste in a Zn refinery operated using a hydrometallurgical flowsheet was studied. Indium content in the residue was 86 mg/kg. A laboratory optimization for the indium extraction processes was done using multifactorial regression analysis. First, the optimal leaching conditions were determined: stirring time 97.7 h; HCl concentration 6.8 M and using a ratio 9.403 g of residue per 50 mL of leaching solution obtaining 96.8% of leaching yield. Secondly, two extraction methods were evaluated, using either a solvent extraction or polymeric inclusion membranes. The proposed optimal conditions for solvent extraction are: aqueous to organic phase ratio 10; feeding phase pH 3.0, 40%(V/V) D2HEPA in kerosene and a stirring time of 4.5 min with 2 consecutive extractions resulting in 83.2% of indium recovery, giving an indium concentration of 97.1 mg/L. The optimal conditions for indium recovery using polymeric inclusion membranes are: stirring time of 3.1 h, a mass ratio of 1.44 (mD2HEPA/mPVC), a feeding phase pH = 3.0 and [HCl] 6.0 M in the re-extraction phase with 100% indium recovery and an indium concentration of 110 mg/L after ten extractions. The polymer inclusion membranes (PIMs) offer more advantages for indium recovery because of its high reusability, lower cost, simple operation process and little environmental pollution. The co-extraction of Fe(III) was minimized, reducing Fe(III) to Fe(II) using Fe° and Sn(II). A selective precipitation using ammonia was carried out to enrich and purify indium, and to recover it in solid form as indium hydroxide. The methodology proposed in this study that managed to efficiently extract In from a metallurgical waste could be the basis for developing methodologies to the extraction of In and/or other strategic elements from other metallurgical waste, given the reuse of these wastes as alternative sources of strategic elements.

ALCHEMILLA VULGARIS'TEN FENOLİK BİLEŞİKLERİN EKSTRAKSİYON KOŞULLARININ YANIT YÜZEY YÖNTEMİ KULLANILARAK OPTİMİZASYONU

The object of this study is to determine the best solvent and optimum extraction conditions for extraction of maximum phenolic compounds from Alchemilla vulgaris leaves. Extractions were carried out using solvents with different polarities. Box-Behnken Design was used to optimize extraction conditions including extraction time, temperature, and liquid/solid ratio. In the study, extract obtained with acetone-water indicated the highest total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity. Optimum extraction conditions for both responses were found as 168 min, 48.5 °C, and liquid/solid ratio of 41:1. The maximum TPC and TFC values were determined as 7.17 mg GAE/gdw and 3.63 mg QE/gdw under optimum extraction conditions. Concentrations of five phenolic compounds analyzed by HPLC increased significantl after optimization. The results indicated that optimizing extraction conditions is critical for quantification of phenolic compounds. The present model can contribute to food industry where phenolic compounds have potential use as biopreservatives.

Pb-Zn recovery from a malic leach solution of a carbonate type ore flotation tailing by precipitation and solvent extraction

The recovery of zinc and lead from a malic leach solution of a carbonate type ore flotation tailing by precipitation with sulfuric acid followed by solvent extraction using di(2-ethylhexyl)phosphoric acid (D2EHPA) as extractant was investigated. The separation of lead via precipitation was essentially complete from the malic acid leach solution by adding sulphuric acid to reach a pH of 0.25 at 25 °C. The precipitate product was identified by XRD as anglesite (PbSO4). The pregnant leach solution after lead precipitation was then subjected to solvent extraction using D2EHPA. The optimum solvent extraction conditions were determined as 10% D2EHPA concentration, 25 °C temperature, 10 min contact time and phase ratio of unity. Under these conditions, 99.3% of zinc was extracted into the organic phase at a pH of 4.2 in a single contact alongside a substantial amount of Ca (76.6%), and minor amounts of Fe (19.2%) and Mg (18%). Complete stripping of zinc and calcium from the loaded organic solution along with 47.8% of Mg was achieved at a pH 0.5 under room temperature. No iron stripping was observed from the loaded organic. The zinc content in the loaded strip solution could be enriched and then sent to the electrowinning (EW) stage. It is noted that the calcium and magnesium impurities in the loaded strip solution had no adverse effect on the zinc EW process. Based on the experimental results, a flowsheet was proposed for the recovery of Pb and Zn from the malic acid leach solution. With the proposed precipitation and solvent extraction process, two different material streams are produced.

Evaluation of Mono-Diacyl Glycerol (MDAG) purification process to increase product yield

Monodiacyl glycerol (MDAG) was successfully synthesized by esterification of palm fatty acid distillate (PFAD) and glycerol with acid catalyst. MDAG products with mono and diacyl glycerol content > 90% were obtained after purification through solvent extraction and crystallization at low temperature. However, the yield of purified MDAG products was only around 16.23% so it was not economically feasible. The aim of this study was to evaluate effect of the hydrolysis process before the esterification process and got the best conditions of solvent extraction in the MDAG purification, to improve yields of purified MDAG. The hydrolysis process was done on PFAD (or PFAD activation) to break down the remaining triglyceride and maximize the presence of free fatty acid that can react with glycerol. Evaluation of solvent extraction process included determination of crude MDAG and hexane ratio (1:10, 1:8, 1:4), determination of ethanol to water volume ratio (1:0, 1:0.5, 1:1, 0.5:1) with various immersion duration (24, 48, 72 h). The data analysis was done with a description method and completely randomized design method (CRD) with a significance level of 5% (P <0.05 %). The activation of PFAD was carried out by reacting PFAD with water at ratio of 1:6 (w/v). This process used para-toluene sulfonic acid (pTSA) as a catalyst, which added as much as 1.2% of the weight of PFAD. The hydrolysis process was done for one hour at 110 °C. From esterification using pre-treated PFAD obtained crude MDAG with FFA content of 4.69%, yield of purified MDAG of 24.7% with no FFA was detected. The best MDAG to hexane ratio was 1:10 which has a yield of purified MDAG of 19.30% and 0% FFA content. While the best ethanol to water volume ratio was 1:0.5 with immersion time for 24 h, where the yield of purified MDAG was 27.78%.

Ultrasound‐microwave assisted extraction of proteins from Moringa oleifera leaves: Comparative optimization study and LC‐MS analysis of the protein concentrate

Moringa oleifera leaves contain significant amount of high quality protein which can be utilized as nutrition supplements and food functional ingredients. In this study, the extraction process of M. oleifera leaves protein was optimized by response surface methodology. Traditional solvent extraction conditions for maximum protein recovery were 0.15-M Tris-HCl concentration, 38-min extraction time, and 128:1 (v/w) solvent/solid ratio at 34°C, and the protein yield was 68.99 mg/g. Furthermore, ultrasound-microwave assisted extraction (UMAE) was adopted to product the leaves protein, and the results showed that the optimum extraction conditions were solvent/solid ratio 91:1 (v/w), extraction time 148 s, extraction temperature 41°C, microwave power 81 W, the yield of protein was 82.07 mg/g. Compared with the conventional solvent extraction method, UMAE exhibited significantly high extraction efficiency. Through LC-MS technology identification and bioinformatics analysis, it is verified that the extracted proteins could provide energy and material basis for the functions of M. oleifera leaf. Practical applications Moringa oleifera leaves have a high protein content and reasonable composition of essential amino acids, which is a high-quality plant protein with great development potential. In the present study, the response surface method was used to optimize the process of ultrasonic and microwave synergistic extraction of M. oleifera leaves protein, which is effective and significantly increased the protein yield. According to the results of LC-MS identification and bioinformatics analysis, the proteins played a leading role in maintaining the normal tissue, structure, and function of M. oleifera leaves, participated in the growth and metabolism of M. oleifera leaves, and provided material and energy supply for the functional performance of M. oleifera leaves.

Effect of accelerated solvent extraction conditions on the isolation of bioactive compounds from fennel (Foeniculum vulgare Mill.) seeds

This study focused to establish the optimal conditions of accelerated solvent extraction (ASE), i.e., temperature, static extraction time and number of extraction cycles, for the isolation of fennel (Foeniculum vulgare Mill.) seeds phenols and pigments using 96% ethanol as an extraction solvent. Hence, extraction conditions of temperature (80 and 110 °C), static extraction time (5 and 10 min) and number of extraction cycle (1, 2, 3 and 4) were varied. Obtained extracts were spectrophotometrically analyzed for the content of total phenols (TP), total chlorophylls (TCHL) and total carotenoids (TCAR). Applied extraction conditions had a significant (p&amp;lt;0.01) influence on the yields of analyzed compounds, except for static extraction time on TCAR (p=0.11). Based on the results of statistical analysis, the highest levels of TP and TCHL were achieved at the most invasive conditions (110 °C/10 min/4 cycles), while shorter period was sufficient to reach the highest TCAR yield (110 °C/5 min/3 cycles). In summary, ASE demonstrated to be effective extraction technique for the isolation of fennel seeds hydrophilic and lipophilic bioactive compounds.

OPTIMIZATION OF ANTIOXIDANT EXTRACTION FROM KALUMPIT (TERMINALIA MICROCARPA DECNE) FRUITS

The effects of extraction parameters, including temperature (25 – 80 °C), time (30 – 90 min), solvent to sample (S/S) ratio (10 – 50 mL g-1), initial pH (3 - 8) and ethanol concentration (20 – 100%), on the % 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of kalumpit were screened and optimized using 2-level factorial design and Box-Behnken design (BBD) of experiments. Temperature, S/S ratio, and ethanol concentration exhibited significant effects on the % DPPH radical scavenging activity of kalumpit extract. Response surface models developed for % DPPH and 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activities of kalumpit fruit extract adequately fit and were used to determine the optimum extraction conditions. A desirability function approach determined the optimum conditions for solvent extraction of antioxidants at 80.0 °C, 10 mL g-1 S/S, and 51.66% ethanol concentration. This resulted in a maximum desirability value of 0.977 and predicted % DPPH and ABTS radical scavenging activities of 66.63 and 82.14, respectively. Validation of the adequacy of the predictive models showed no significant difference between experimental data and predicted values (p &gt; 0.05), indicating that the models developed were adequate in describing the relationship between factors and responses.

Beneficiation of eucalyptus tree barks in the context of an integrated biorefinery – Optimisation of accelerated solvent extraction (ASE) of polyphenolic compounds using response surface methodology

Bark from trees obtained from sustainably managed plantations used in the production of timber, pulp and paper is an under-utilised waste in many countries across the world. However, in the context of an integrated biorefinery, they may serve as a valuable feedstock for the production of high-value products for increased revenue generation and mitigation of environmental impacts for the ailing forestry, timber, pulp and paper industry. In this study, optimum accelerated solvent extraction conditions were established for the recovery of total polyphenolic compounds (TPC) and total extractive content (TEC) from barks obtained from four Eucalyptus tree species (E.dunnii, E.grandis, E.smithii and E.nitens). Using a response surface methodology and Box-Behnken experimental design, optimum extraction conditions found were an extraction temperature of 117 °C, three extraction cycles, and a milled bark particle size class of 500–850 μm. E. smithii showed the highest TEC at 21.9% and the highest TPC at 4.7 g/100 g gallic acid equivalents (GAE).

Polymer-Supported Phosphoric, Phosphonic and Phosphinic Acids-From Synthesis to Properties and Applications in Separation Processes.

Efficient separation technologies are crucial to the environment and world economy. The challenge posed to scientists is how to engineer selectivity towards a targeted substrate, especially from multicomponent solutions. Polymer-supported reagents have gained a lot of attention in this context, as they eliminate a lot of inconveniences concerning widely used solvent extraction techniques. Nevertheless, the choice of an appropriate ligand for immobilization may be derived from the behavior of soluble compounds under solvent extraction conditions. Organophosphorus compounds play a significant role in separation science and technology. The features they possess, such as variable oxidation states, multivalence, asymmetry and metal-binding properties, highlight their status as a unique and versatile class of compounds, capable of selective separations proceeding through different mechanisms. This review provides a detailed survey of polymers containing phosphoric, phosphonic and phosphinic acid functionalities in the side chain and covers main advances in the preparation and application of these materials in separation science, including the most relevant synthesis routes (Arbuzov, Perkow, Mannich, Kabachnik-Fields reactions, etc.), as well as the main stages in the development of organophosphorus resins and the most important achievements in the field.

Influence of Accelerated Solvent Extraction Conditions on the LC-ESI-MS/MS Polyphenolic Profile, Triterpenoid Content, and Antioxidant and Anti-lipoxygenase Activity of Rhododendron luteum Sweet Leaves.

Evaluation of native plant resources and their efficient use is one of the current trends in phytochemistry. The main aim of the present study was to investigate the biological activities of different Rhododendron luteum Sweet leaf extracts obtained with the use of accelerated solvent extraction using different solvents and extraction temperatures. All extracts were subjected to bioactivity assays, which revealed considerable anti-lipoxygenase (23.07–90.13% lipoxygenase inhibition) and antiradical potential. All samples exhibited high 2,2-diphenyl-1-picrylhydrazyl (DPPH•) (234.18–621.90 mg Trolox equivalents (TE)/g) and 2,2′-azino-bis-3(ethylbenzthiazoline-6-sulphonic acid) (ABTS•+) (88.79–349.41 mg TE/g) scavenging activity, high antioxidant potential in the Oxygen Radical Absorbance Capacity (ORAC) assay (495.77–1011.59 mg TE/g), and moderate ion chelating (Fe2+) capacity. The chemical profile of each sample was determined using liquid chromatography/electrospray ionization triple quadrupole mass spectrometry (LC-ESI-MS/MS) and spectrophotometric procedures. Twenty-three compounds representing seven polyphenol subclasses were detected and quantified, including some phenolic acids and flavonoids that had not been previously reported for this plant material. It was shown that 5-O-caffeoylquinic acid, protocatechuic acid, catechin, quercetin and its glycosides (hyperoside, isoquercetin, quercitrin), and pentacyclic triterpenes were the dominant secondary metabolites in R. luteum leaves. The antioxidant activity was found to be strongly related to different polyphenol groups and total triterpene content, while the anti-lipoxygenase potential was highly dependent on catechin.

Separation of lithium and transition metals from leachate of spent lithium-ion batteries by solvent extraction method with Versatic 10

When extracting metals from the leaching liquor of spent lithium-ion batteries (LIBs), the focus of traditional methods has been putting on the separation of transition metals, i.e. manganese, cobalt and nickel, which needs a long treatment process and causes significant loss of lithium. In this study, a simple and efficient process consisting of co-extraction of transition metals with neodecanoic acid (Versatic 10) and recovery of lithium by carbonate precipitation is developed. Firstly, the extraction mechanism of Versatic 10 is explored by slope analysis. And the results show that Versatic 10 has better selectivity to nickel and cobalt than to manganese, and it hardly extracts lithium. Then, practical experiments on solvent extraction conditions are carried out. The total extraction efficiencies of nickel, manganese and cobalt, after two stages of extraction, reach 99.18%, 97.05% and 98.47%, respectively. The experimental results are consistent with the theoretical analysis results. Finally, lithium is recovered by Na2CO3 precipitation. The purity of recovered lithium carbonate is high up to 99.61%. By using this process, the obtained solution of nickel, manganese and cobalt can be directly used to prepare ternary material precursor, and only 8% of lithium is lost.

Optimizing the extraction of anthocyanins from purple passion fruit peel using response surface methodology

Purple passion fruit peel (PPFP) is a waste with high antioxidant capacity. Therefore, in this work, the conditions for solvent extraction of anthocyanins from that peel were studied according to the following variables: temperature, pH, solvent: raw material ratio and time, using the response surface methodology. Additionally, the antioxidant capacity of the extract was characterized, and its respective anthocyanin degradation kinetics were performed at three storage temperatures. The best conditions were pH 2.0, 52.03 °C, 29.79 g of solvent per g of raw material and 180 min, which gave an anthocyanins extraction yield of 577.59 mg of cyanidin-3-O-glucoside per 100 g of dry raw material. The extract also showed 490.12 ± 2.57 and 528.85 ± 27.17 µmol Trolox per 100 g of antioxidant capacity by DPPH and FRAP essays respectively, a low content of vitamin C, as well as activation energy of 41.4 kJ per mole. Consequently, this study shows PPFP as a potential raw material in anthocyanins and antioxidants extracts, which have a great value in the food industry with their stability under refrigeration. Above mentioned displays an alternative strategy for using this waste as a source of high-value products.

Determination of nicotine in wild edible fungi by QuEChERS-ultra performance liquid chromatography-triple quadrupole mass spectrometry

Yunnan Province has many wild edible fungi resources, and of these, endogenous nicotine has received extensive attention in recent years. In this study, wild edible fungus was used as the research object, and the QuEChERS method was improved, including optimization of solvent extraction and purification conditions and optimization of the chromatographic behavior of nicotine under different mobile phase conditions for ultra performance liquid chromatography (UPLC). Combined with triple quadrupole mass spectrometry, a high-efficiency, rapid, and sensitive method for the determination of nicotine in wild edible fungi was established. The results showed that an ammonia:acetonitrile (6:94, v/v) mixed solution can completely extract nicotine from wild edible fungi, and the extraction solution was purified by graphitized carbon black (GCB) and N-propylethylenediamine (PSA) mixed filler. Then, a 0.1% (volume percentage) ammonia solution and acetonitrile were used as the mobile phases. The nicotine peak obtained in the positive ion multiple reaction monitoring (MRM) mode had a better peak shape and better response. The linear relationship of nicotine mass concentration with peak area in the range of 0.05-50.0 μg/L was good. The correlation coefficient (r2) was 0.9999. The limit of quantification was 0.2 μg/kg, and the limit of detection was 0.05 μg/kg. The average recovery rates at three spiked concentrations were in the range of 86.34%-96.4%, and the relative standard deviations varied from 4.44% to 6.3%. The sensitivity and recovery of this method are consistent with the rapid determination of nicotine in the edible fungus industry.

Multi-response optimization of oil extraction from pine nut (Pinus pinea L.) by response surface methodology: Extraction efficiency, physicochemical properties and antioxidant activity

Effects of solvent extraction conditions on the extraction efficiency, physicochemical properties and antioxidant activity of pine nut oil were investigated and optimized by using three level Box-Behnken design (BBD). Temperature (25–65 °C), time (10–60 min) and solvent/sample (S/S) ratio (5–20 mL g−1) were chosen as the independent variables while the dependent variables were extraction efficiency, yellowness index (YI), peroxide value (PV), p-anisidine value (p-AnV), totox value (TV), DPPH-hydrophilic fraction (DPPH-HF), DPPH-lipophilic fraction (DPPH-LF) and DPPH-oil to obtain pine nut oil with high oil yield, and desirable physicochemical properties and antioxidant activity. N-hexane was found to be the most effective solvent for the extraction. Extraction efficiency, physicochemical properties and antioxidant activity of pine nut oil were highly affected by temperature, time and S/S ratio. Desirability function approach was used to determine optimum conditions. The optimum conditions for the production of pine nut oil with solvent extraction were attained at the extraction temperature of 39.3 °C, extraction time of 33.4 min and S/S ratio of 10.8:1 (mL g−1). At optimum conditions, the predicted values for the extraction efficiency, YI, PV, p-AnV, TV, DPPH-HF, DPPH-LF and DPPH-oil yielded 80.03%, 59.89, 1.05 meq peroxide kg−1 oil, 0.92, 3.02, 8.60%, 65.07% and 73.35%, respectively.

Evaluation of antioxidant and antimicrobial properties of solvent extracts of agro-food by-products (cashew nut shell, coconut shell and groundnut hull)

In India, agro-food by-products such as shell cake of cashew nut (Anacardium occidentale L.), shell of coconut (Cocos nucifera L.) and hull of groundnut (Arachis hypogaea L.) are cheaply available on a vast scale. Even though a small portion of these solid waste materials is being used, a large quantity is not being utilized. Based on literature data, these by-products could be used as a source of valuable phytochemicals. The present study explored a suitable solvent system and extraction conditions for the recovery of polyphenols from three different agro-food by-products. The optimal conditions for the recovery of polyphenols from agro-food by-products were investigated in addition to evaluating their antioxidant and antibacterial properties. Among the three investigated by-products, methanolic extract of cashew nut shell was the most prominent source of antioxidants (3412.28 mg gallic acid equivalent (GAE)/L) compared to coconut shell (1056.32 mg GAE/L) and groundnut hull (426.35 mg GAE/L). The in vitro antioxidant assay produced promising radical scavenging activity of shell extract of coconut (concentration at which the response was reduced by half; IC50 = 12 μg/mL) compared to cashew nut (IC50 = 44 μg/mL) and groundnut hull extract (IC50 = 48 μg/mL). The anti-bacterial activity of different solvent extracts revealed that the methanolic extracts from cashew nut and coconut shells were more effective in inhibiting the growth of both Gram-positive and Gram-negative bacteria. The present work revealed the possibility of recovery of useful phytochemical compounds from agro-food byproducts which could be used subsequently as natural food preservatives.

Solvent Extraction of Polyphenolics from the Indigenous African Fruit Ximenia caffra and Characterization by LC-HRMS.

Indigenous and non-commercial fruits can be an important source of antioxidant polyphenols; however, the identity and content of polyphenols from non-commercial fruits are often poorly described. The study aimed to extract, identify, and quantify polyphenols from the skin of the indigenous Africa fruit Ximenia caffra, using solvent extraction. Three solvents (hexane, acetone, and 70% v/v ethanol) over three extraction times (30, 60 and 120 min) were used in a 32 full factorial experimental design to determine effects on polyphenol recovery, and individual polyphenolics were characterised using liquid chromatography high-resolution mass spectrometry (LC-HRMS). Ethanol was the most effective extraction solvent, and extracts had high levels of total phenolics and flavonoids (65 mg gallic and 40 mg catechin equivalents per gram dry sample respectively), and high antioxidant activity (18.2 mg mL−1 ascorbic acid equivalents). LC-HRMS positively identified 16 compounds, of which 14 were flavonoids including flavonoid glycosides, and indicated that concentrations of some flavonoids decreased for extraction times beyond 60 min. It was concluded that the fruit of Ximenia caffra is rich in natural polyphenolic antioxidants; the present work identified and quantified a number of these, while also establishing suitable solvent extraction conditions for the recovery of these potentially high-value compounds.

A study on Zn recovery from other metals in the spent mixed batteries through a sequence of hydrometallurgical processes

ABSTRACTA study on selective separation of Zn from a leaching solution by disposal batteries including various type batteries was carried out to understand the recovery behaviour of Zn in leaching solution. Selective recovery of Zn in leaching solution including Mn, Cd, Cu ion was difficult due to its similar physicochemical behaviour. Experiment results by present leaching solution with 279 µm undersize indicated that the best condition for leaching is 1 M H2SO4, 250 rpm, 5 vol.% H2O2 and 353 K and the leaching efficient of Zn, Co and Mn is approximately 97%, respectively. The exclusive extraction behaviour of Zn by using D2EHPA is indicated that the best conditions for solvent extraction are to be 0.6 M D2EHPA diluted with kerosene, 30% saponification, 298 K, 5-min contact time and three-stage countercurrent extraction, and the O/A ratio 1, respectively. Recovery of Zn was with approximately 99.7% selectively from Mn, Co, Ni, Cd and Li. After scrubbing 5 times by pH 2 modified solution and single stripping experiment by 1.5 M H2SO4, the solution including Zn of 9.0 g/L can be produced.