Gold Mine Closure and Decommissioning: 1 - 5 years. After a mine has ceased operations, possibly because the ore body is exhausted or the remaining deposit becomes unprofitable (uneconomic) to mine, work then focuses on its decommissioning, dismantling and rehabilitation of the land in which it was situated.
In this study, gold nanoparticles (AuNPs) modified with β-cyclodextrin (β-CD) were used to assist with electromembrane extraction (EME) and were coupled with capillary electrophoresis (CE) and ultraviolet (UV) detection (CE-UV) for the extraction and measurement of methadone from plasma samples. A β-CD-modified AuN
An alkali metal cation-dependent approach to gold recovery, facilitated by second-sphere coordination with eco-friendly α-cyclodextrin (α-CD) is reported, which develops an efficient process for green gold recovery. Herein, we report an alkali metal cation-dependent approach to gold recovery, facilitated by second-sphere coordination …
The initial experimental conditions during the optimization were (1) 100 ng mL −1 of methadone, 750 rpm as the stirring rate, voltage of 15 V, 15 min extraction time, donor solution pH of 7.0, and 300 μL of β-CD-modified AuNPs for effect of the SLM composition on the EME and β-CD-modified AuNPs/EME methods; (condition), (2) 100 ng mL −1 ...
In the present study we carried out the synthesis of β-cyclodextrin (β-CD) functionalized gold nanoparticles (AuNPs) using a microwave assisted heating method in alkaline media. Stable dispersion of β-CD stabilized AuNPs was obtained at an optimized pH of 10.5. At this pH value the deprotonated secondary hydroxyl group of β-CD shows …
Development of a b-cyclodextrin-modified gold nanoparticle-assisted electromembrane extraction method followed by capillary electrophoresis for ... SLM to increase the efficacy of the EME method ...
In a new study published in Nature Communications1, a joint team of researchers from the United States and Saudi Arabia, led by Zhichang Liu from …
β-cyclodextrin (β-CD) is a widely available, low-cost and environmentally benign cyclic oligosaccharide with intrinsic cavity and rich and chemically adjustable hydroxyl groups, which have been widely employed to construct versatile adsorbent materials for water treatment and resource recovery (Hartlieb et al. 2016, Liu et al. …
The invention relates to a manufacturing method of a beta-cyclodextrin matrix solid-phase micro-extraction head, belonging to the trace analysis field of volatile and semi-volatile organic matter in foods, environment and biological samples. The manufacturing method comprises the following steps of: (1) selecting and pretreating quartz fiber; (2) …
The commonly used method for gold extraction is the cyanide leaching process, where a cyanide solution is used to dissolve the gold from the ore in tanks or heaps [17].
An HPLC method for micro determination of BCD and glucosyl-BCD in urine, kidney, liver, and feces of the rat was described by Fukada et al. in 1993 using solid-phase extraction through a mini column packed with C18-bonded silica followed by treatment with strong cation exchange resin [74].
α-Cyclodextrin is a dietary fiber being researched as a potential weight loss supplement due to its ability to bind 9 times its weight in fat.
This study aimed to optimize a green extraction method, combining ultrasound, stirring, and β-cyclodextrin (BCD) aqueous solutions to recover the bioactive compounds from this olive by-product. The optimal conditions to maximize extraction yields of antioxidant compounds in water or ethanol were: solid-to-solvent ratio 1:20 w/w ...
This process of co-precipitation between -CD and KAuBr4 in water achieved promising results in α terms of selective gold recovery (up to ∼80% at 20°C), even carried out in …
The current work focuses on the extraction of gold using alpha-cyclodextrin (α-CD) from the Kimpese quarry in the Democratic Republic of the Congo, through an environmentally friendly gold ...
This green method extracts gold from crude sources and leaves behind other metals that are often found mixed together with the crude gold. The new process …
The good recovery rates (101.8% and 102.5% for pyrene and 106.4% and 101.7% for anthracene) confirmed the reliability of the method. Graphical abstractSchematic illustration of SERS signal enhancement of pyrene, as an example of polycyclic aromatic hydrocarbons, by β-cyclodextrin modified gold nanoparticles.
Regarding the importance and new advances on the field of CDs and food science, some recent reviews have been focused on the latest updates of the use of CDs in food products such as nanoparticles, nanosensors, extraction enhancers, active or smart packaging, and their most widespread use as carriers and complexes formers to protect …
Discover a cost-effective and eco-friendly method to extract gold from electronic waste and soil using alpha-cyclodextrin. Achieve high recoveries of up to 70.8% with this efficient …
Extraction of Cholesterol with Methyl-β-Cyclodextrin Perturbs Formation of Clathrin-coated Endocytic Vesicles ... culture flasks were washed with PBS and incubated for 2 h at room temperature with goat anti-mouse IgG coupled to 10 nm gold (Amersham), washed, scraped off, and processed for EM. ... and after 15 min further incubation the …
Herein, we report an alkali metal cation-dependent approach to gold recovery, facilitated by second-sphere coordination with eco-friendly α-cyclodextrin (α-CD).
This green method extracts gold from crude sources and leaves behind other metals that are often found mixed together with the crude gold. The new process also can be used to extract gold from consumer electronic waste.
3.1 Synthesis of the Catalysts. Gold nanoparticles protected by a monolayer of perthiolated β-cyclodextrin were prepared by the reported procedure [], and the theoretical molar ratio of CD to AuCl4 − is calculated to be 0.14:1.The resulting water-soluble gold nanoparticles (1) were characterized by 1 H NMR and UV–vis …
In the gold-mining process, the precious metal is often extracted from low-grade ore in a technique known as gold cyanidation. ... "Alpha-cyclodextrin is the gold medal winner," said Sir ...
Based on the subtle changes in the analyte affinity for the fluorophore and the cyclodextrin cavity, this method offered a straightforward sample preparation strategy and a rapid signal readout mode. This method was able to detect 15 phthalate esters with highly analyte-specific responses and at concentrations as low as 0.12 μM.
In this work, methyl β-cyclodextrin (Mβ-CD) was used to increase the solubility of turmeric rhizome oleoresin (TRO) in aqueous solution by forming inclusion complexes, and the technique was combined with microwave-assisted extraction (MAE) to extract the curcuminoids from Curcuma domestica Val. Optimized conditions for the …
This discovery heralds a green host–guest procedure for gold recovery from gold-bearing raw materials making use of α-cyclodextrin—an inexpensive and …
These results suggest that additive-induced polymerization can be used to recover the gold from low-grade gold ores and low-concentration gold-bearing …
2. History of Cyclodextrins. α- and βCD were discovered in 1891 by the French pharmacist and chemist Antoine Villiers as digestion products of potato starch obtained by using the bacterium Bacillus amylobacter (Figure 2).Villiers named the novel carbohydrates "cellulosines" α- and β-dextrin and described them as crystalline and …
A rapid and efficient magnetic solid phase extraction (MSPE) method, based on Fe3O4@β-cyclodextrin–lipid bilayer nanocomposites (Fe3O4@β-CD–LB), was built. The MSPE method coupled with GC-QTOF-MS has been designed for the trace detection of nine organochlorine pesticides (OCPs) in soil samples. The Fe3O4@β-C
