scholarly journals New extraction technique of zirconium and hafnium from zircon mineral

2019 ◽  
Vol 52 (2) ◽  
pp. 201-208
Author(s):  
Ahmed Abd El_Kareem
Keyword(s):  
Extraction Technique ◽  
Zircon Mineral

The Use of a Sequential Extraction Technique to Characterize Soil Trace Evidence Recovered from a Spade in a Murder Case in Brazil*

2020 ◽  
Vol 65 (6) ◽  
pp. 1921-1934 ◽  
Author(s):  
Samara Alves Testoni ◽  
Vander Freitas Melo ◽  
Lorna Anne Dawson ◽  
Joice Malakoski ◽  
Edimar Cunico ◽  
...  
Keyword(s):  
Sequential Extraction ◽  
Extraction Technique ◽  
Trace Evidence

scholarly journals Extraction Methods and Their Influence on Yield When Extracting Thermo-Vacuum-Modified Chestnut Wood

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 73
Author(s):  
Maurizio D’Auria ◽  
Marisabel Mecca ◽  
Maria Roberta Bruno ◽  
Luigi Todaro
Keyword(s):  
Catalyst Support ◽  
Castanea Sativa ◽  
Extraction Methods ◽  
Extraction Technique ◽  
Extraction Techniques ◽  
Surface Color ◽  
Ms Analysis ◽  
Castanea Sativa Mill ◽  
Molybdenum Catalysts ◽  
Chestnut Wood

Improvements in the yield and solubility of chestnut wood extractives, by using different extraction methods and molybdenum catalysts as support, have rarely been reported in literature. Many studies focus on the different parts of trees, except for the chemical characteristics of the remaining extractives achieved from thermally modified (THM) chestnut (Castanea sativa Mill) wood. This research seeks to better understand the effects of extraction techniques and catalysts on the yield and solubility of extractives. GC-MS analysis of the chloroform soluble and insoluble fractions was also used. Accelerated Solvent Extraction (ASE) 110 °C, Soxhlet, and autoclave extraction techniques were used to obtain extractives from untreated and thermally modified (THM) chestnut wood (170 °C for 3 h). Ethanol/H2O, ethanol/toluene, and water were the solvents used for each technique. A polyoxometalate compound (H3PMo12O40) and MoO3 supported on silica were used as catalysts. The THM induced a change in the wood’s surface color (ΔE = 21.5) and an increase in mass loss (5.9%), while the equilibrium moisture content (EMC) was reduced by 17.4% compared to the control wood. The yields of the extractives and their solubility were always higher in THM and mainly used ASE as the technique. GC-MS analysis of the extractives, without catalyst support, showed different results for each extraction technique and type of wood (untreated and THM). Ultimately, the amount of extractive compound dissolved in each solvent will differ, and the choice of extraction technique will depend on the intended final application of the extracted chemical product.

scholarly journals Optimizing the ultrasonic-assisted extraction of antioxidants from Ulva lactuca algal biomass using factorial design

2021 ◽  
Author(s):  
Sayed Rashad ◽  
Ghadir El-Chaghaby ◽  
Eder C. Lima ◽  
Glaydson Simoes dos reis
Keyword(s):  
Factorial Design ◽  
Algal Biomass ◽  
Ulva Lactuca ◽  
Extraction Technique ◽  
Extraction Solvent ◽  
Assisted Extraction ◽  
Study Results ◽  
Ultrasonic Assisted ◽  
Ultrasonic Assisted Extraction ◽  
Optimum Extraction

AbstractUltrasonic-assisted extraction (UAE) is increasingly emerging as a highly effective extraction technique. This extraction technique is affected by several experimental factors. The present work aimed to optimize the ultrasonic-assisted extraction of antioxidants from Ulva lactuca (sea lettuce), widespread macroalgae growing along the Mediterranean coast. In this respect, a full-factorial design (23) was employed to assess the effect of three different factors at two levels and their interactions on the extraction of antioxidants from sea lettuce algal biomass. The studied factors were extraction solvent, time of extraction, and temperature. The two levels chosen for extraction solvent were 100% ethanol and 50% ethanol, for the sonication time (1 h and 3 h) and temperature (25 °C and 40 °C). All experiments were done using an ultrasonic bath, and the biomass to solvent ratio was kept at 1:5. Total antioxidant capacity and quercetin concentration were set as the two responses for optimum output. The results showed that the temperature and solvent were the dominating factors that significantly affect the extraction process. The optimum extraction parameters were extraction time of 1 h, 50% ethanol, and temperature of 25 °C. Under these conditions, the maximum value for TAA was calculated as 2166.51 mg of ascorbic acid equivalent per gram (mg/g of AAE), and quercetin showed a maximum calculated value of 42.5 mg/g with combined desirability of 0.91 for the two responses. The present study results indicate that U. lactuca can be used as a source of antioxidants and phenolic compounds that can be applied in food and medicine at optimum extraction conditions. Graphical abstract

scholarly journals Sustainable Processing of Floral Bio-Residues of Saffron (Crocus sativus L.) for Valuable Biorefinery Products

Plants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 523
Author(s):  
Stefania Stelluti ◽  
Matteo Caser ◽  
Sonia Demasi ◽  
Valentina Scariot
Keyword(s):  
Phenolic Compounds ◽  
Vitamin C ◽  
Antioxidant Properties ◽  
Crocus Sativus ◽  
Extraction Technique ◽  
Ultrasound Assisted Extraction ◽  
Average Value ◽  
Assisted Extraction ◽  
High Yields ◽  
Crocus Sativus L

Tepals constitute the most abundant bio-residues of saffron (Crocus sativus L.). As they are a natural source of polyphenols with antioxidant properties, they could be processed to generate valuable biorefinery products for applications in the pharmaceutical, cosmetic, and food industries, becoming a new source of income while reducing bio-waste. Proper storage of by-products is important in biorefining and dehydration is widely used in the herb sector, especially for highly perishable harvested flowers. This study aimed to deepen the phytochemical composition of dried saffron tepals and to investigate whether this was influenced by the extraction technique. In particular, the conventional maceration was compared with the Ultrasound Assisted Extraction (UAE), using different solvents (water and three methanol concentrations, i.e., 20%, 50%, and 80%). Compared to the spice, the dried saffron tepals showed a lower content of total phenolics (average value 1127.94 ± 32.34 mg GAE 100 g−1 DW) and anthocyanins (up to 413.30 ± 137.16 mg G3G 100 g−1 DW), but a higher antioxidant activity, which was measured through the FRAP, ABTS, and DPPH assays. The HPLC-DAD analysis detected some phenolic compounds (i.e., ferulic acid, isoquercitrin, and quercitrin) not previously found in fresh saffron tepals. Vitamin C, already discovered in the spice, was interestingly detected also in dried tepals. Regarding the extraction technique, in most cases, UAE with safer solvents (i.e., water or low percentage of methanol) showed results of phenolic compounds and vitamin C similar to maceration, allowing an improvement in extractions by halving the time. Thus, this study demonstrated that saffron tepals can be dried maintaining their quality and that green extractions can be adopted to obtain high yields of valuable antioxidant phytochemicals, meeting the requirement for a sustainable biorefining.

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