the chemical speciation of heavy metals (arsenic, chromium, copper, lead, zinc and tin) in the sediments offormer tin mining catchment bestari jaya, peninsular malaysia was determined by using the latest version of the community bureau of reference, usually called the bcr 3-step sequential extraction procedure. furthermore, a fourth step was introduced for digestion and analysis of the residue....

Conventional extraction (CE) and microwave-assisted (MAE) were compared in terms of efficiency quality pectin two separate processes aimed to extract from Malus domestica ‘F?lticeni’ apple pomace. A similar yield a shorter time was observed for the procedure as CE, while galacturonic acid content degree esterification both methods. Apple extracted this plant source by methods had high content, ...

The LiMn1.5Ni0.5O4 spinel is an important lithium ion battery cathode material that has continued to receive major research attention because of its high operating voltage (∼4.8 V). This study interrogates the impact of microwave irradiation on the Mn(3+) concentration and electrochemistry of the LiMn1.5Ni0.5O4 spinel. It is shown that microwave is capable of tuning the Mn(3+) content of the sp...

Results of theoretical and experimental studies of a GW-class, large diameter microwave oscillator are presented. The device consists of a large cross-section (overmoded), slow-wave structure with a unique profile of wall radius specifically designed to support surface waves and to provide a strong beam-wave coupling at moderate voltage (500 kV), an internal adjustable microwave reflector, a co...

In this study, three extraction methods of polysaccharides in Purslane were compared and analyzed, and the best method was ascertained. Purslane polysaccharides were extracted using water, ultrasonic and microwave. By the results of single factor experiments and orthogonal experiments, the optimal extracting conditions were selected and then the best extraction method was determined. In order t...

In the last 10 years there has been an increased interest in using techniques involving microwave-assisted extraction and pressurised solvent extraction in analytical laboratories. This review gives a brief overview of both methods, and reports on their application to the extraction of natural products. The influence of parameters such as the nature of the solvent and volume, temperature, time ...

the lamiaceae family consists of a broad spectrum of medicinal plants involving marrubium l. genus. regarding the diverse pharmaceutical uses of the plants belonging to this genus, they can be considered as proper alternatives for chemical drugs having harmful effects. the present work aims to identify and characterize chemical compositions of the essential oils and volatiles from the aerial pa...

Microwave-assisted extraction (MAE) and microwave-assisted hydrolysis (MAAH) were developed for the sample preparation of guava leaves prior to GC determination of quercetin and its glycosides. Ethanol was selected as the solvent. The optimum MAE temperature, particle size, solvent volume and MAE time are 120 degrees C, 40 - 60 mesh, 20 mL and 5 min, respectively; the optimum MAAH temperature a...