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Abstract In this work, a quick, facile and efficient approach was presented for green synthesis of cadmium telluride quantum dots (CdTe QDs) based on an aqueous extract of the Ficus johannis plant. Two extraction methods involving microwave assisted extraction (MWAE; 90 and 270 w; 15 min) and ultrasonic assisted extraction (USAE; 15 min; 45 °C) were performed as eco-friendly, effective, green and fast techniques for the extract preparation of the fruit's plant. The as-prepared plant extracts were used as natural stabilizing precursors in the synthesis of CdTe QDs. The synthesized QDs were characterized using various techniques. The average particle size of the QDs from the X-ray diffraction patterns was calculated to be 1.2 nm. UV–Vis absorption and fluorescence spectroscopic studies show a wide absorption band from 400 to 425 nm and a maximum emission peak around 470 nm, which confirmed the successful synthesis of CdTe QDs via the applied synthetic method. After synthesis and characterization of the samples, the antimicrobial properties, genotoxicity, toxicity and antifungal activities of the as-prepared CdTe QDs were investigated. In addition, antioxidant properties of the samples (QDs and extracts), were evaluated by different antioxidant assays. The results indicate the significant antimicrobial activity of the extract and CdTe QDs samples, with negligible toxicity and genotoxicity impacts. Graphical abstract Unlabelled Image Highlights • New report on biosynthesis of CdTe QDs by plant extract obtained by microwave and ultrasonic extraction • Structural and optical studies of as-prepared ultra-small CdTe QDs • Comparative investigation of antimicrobial, antioxidant and genotoxicity properties of the prepared samples [ABSTRACT FROM AUTHOR]

Abstract Microwave assisted extraction (MAE) is recognized as an efficient technique to obtain essential oils (EO) when compared with conventional processes; its efficacy, however, strongly depends on several processing variables. The aim of this work was to evaluate the effect of selected process variables on the extraction of bay (Laurus nobilis) leaves' EO by means of MAE, as well as to describe and simulate the extraction process by means of static and dynamic models. The effect of each process variable was evaluated through statistical analysis based on a response surface design, varying solvent to feed ratio (s:l, 1:1–1:4 g/ml), microwave power (P, 360–540 W), and stirring speed (s, 0–400 rpm). Optimal conditions for EO extraction were achieved when higher values of P (540 W) and s (400 rpm) were combined with the lowest value of s:l (1:1 g/ml). Selected polynomial dependency for modeling the static results, adequately explained the observed responses. From the dynamic analysis, the agreement of the second order equation with the experimental results confirms that the developed dynamic model describes the transient behavior of MAE of bay leaves' EO. Studied variables and their interactions significantly affected (p < 0.05) not only energy requirement and EO yield, but also the extraction mechanism and model parameters. Highlights • Microwave assisted extraction (MAE) of bay leaves' essential oil (EO) was studied. • Solvent to feed ratio (s:l), power (P), and stirring speed (s) were evaluated. • The interaction between P and s is critical for the optimization of MAE. • A dynamic model describing MAE of bay (Laurus nobilis) leaves' EO was presented. • Model parameters were significantly affected by interactions among s:l, P, and s. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • First report on pentacyclic triterpenoids in Indian Swertia from Western Himalayas. • A validated and simultaneous high-performance thin-layer chromatography was performed. • Microwave, heat reflux and Soxhlet extractions were carried out for the triterpenoids. • Microwave coupled with aqueous ethanol was the most efficient method for extraction. • S. paniculata showed promise to substitute S. chirata in triterpenoid content. Abstract Swertia chirata (Family: Gentianaceae) is a potent and valuable medicinal herb used in various herbal formulations in Indian system of medicine. Different species of Swertia are being used as constituents in various herbal formulations. Present study was undertaken for the screening of an efficient extraction technique and for the development of a rapid and simultaneous quantification of four pentacyclic triterpenoids in different populations of Swertia species by a high-performance thin-layer chromatography (HPTLC)-densitometric method. This method involved the separation of four triterpenoids with a single mobile phase composition consisting of n-hexane, ethyl acetate, toluene (14.2, 4, 1.8 v/v). The retention factor (R f) values for oleanolic acid (OA), ursolic acid (UA), betulinic acid (BA), and lupeol (Lup) were 0.25, 0.50, 0.58 and 0.74 respectively. In this study, microwave assisted extraction (MAE) using aqueous ethanol proved to be the most efficient method for extraction for all the studied triterpenoids when compared with the other conventional methods. The present HPTLC method was found to be precise, fast, and cost effective and can be used for the quality control of any Swertia samples with regards to its pentacyclic triterpenoids content. Since, S. chirata is a critically endangered species, the present study depicts the utility of other species of Swertia viz. S. paniculata and S. angustifolia as promising substitutes for S. chirata in herbal preparations. [ABSTRACT FROM AUTHOR]

Due to the great interest in obtaining natural bioactive carbohydrates to be used as functional ingredients, a selective microwave assisted extraction (MAE) method was optimized to ensure the exhaustive extraction of inositols and α-galactooligosaccharides (α-GOS) from mung bean. Thereafter, a comprehensive characterization of these compounds was carried out by gas chromatography coupled to mass spectrometry (GC–MS). Apart from free inositols and α-GOS, several glycosyl-methyl- scyllo -inositols and glycosyl-inositols were detected for the first time in this legume. Under optimized MAE conditions (0.5 g dry sample, 2 cycles of 3 min, 50 °C, 10 mL 50:50 ethanol:water, v:v), bioactive carbohydrates yields were similar to those found using solid–liquid extraction (SLE), but with shorter analytical times. Concentrations of bioactive carbohydrates in MAE extracts from samples of different geographical origins ranged between 74.1 and 104.2 mg.g −1 dry sample. MAE was proved a good alternative to SLE to obtain extracts enriched in bioactive carbohydrates. [ABSTRACT FROM AUTHOR]

Eurycoma longifolia Jack (Tongkat Ali) roots are used in traditional medicines for its wide range of biological effects. The process of extracting out this essential oil from the plant requires a delicate and efficient method. In this research the extract of the essential oil of Eurycoma longifolia's root using Microwave Assisted Extraction (MAE), Soxhlet Extraction and Conventional Steam Extraction (CSE) methods, is characterized to identify the components of essential oil extracted and then to compare the yield percentage and components of the extracts from both methods. The extract obtained was characterized using gas chromatography mass spectroscopy (GC-MS) by comparing the compositions of components present in commercial Tongkat Ali oil stored in the GC-MS library. The findings showed that the MAE gives a maximum yield percentage of 5% with six chemical components extracted in 20 min while SE and CSE gives high yield percentage of 28.3% in 3 h and 2.5% in 6 h respectively with only three chemical components extracted. Therefore, MAE is the optimum method for extracting essential oil from Tongkat Ali with a high quality. [ABSTRACT FROM AUTHOR]

Soxhlet and microwave assisted extraction (MAE) methods were used to obtain non-polar compounds from pistachio hull. MAE parameters (liquid to solid ratio, microwave power, and extraction time) were studied to obtain maximum extraction yield. The optimal conditions were found to be liquid to solid ratio of 15:1 (v/w), microwave power of 250 W and extraction time of 12.5 min. The extraction yields were 9.81 and 9.50% for MAE and Soxhlet methods, respectively. The total phenolic content, antioxidant activity and tocopherol content of the extract obtained by MAE was found to be significantly higher than those of the Soxhlet extract (p < 0.05). The results showed that the extract contained α-tocopherols (567.65 mg/kg) and oleic acid (48.46%) as the major tocopherols and fatty acids. These findings propose that hull extracts can be considered as a good source of natural bioactive compounds and MAE can be a good alternative to the traditional Soxhlet method. [ABSTRACT FROM AUTHOR]

Optimization process is an important aspect in the natural product extractions. Herein, an alternative approach is proposed for the optimization in extraction, namely, the Generalized Likelihood Uncertainty Estimation (GLUE). The approach combines the Latin hypercube sampling, the feasible range of independent variables, the Monte Carlo simulation, and the threshold criteria of response variables. The GLUE method is tested in three different techniques including the ultrasound, the microwave, and the supercritical CO 2 assisted extractions utilizing the data from previously published reports. The study found that this method can: provide more information on the combined effects of the independent variables on the response variables in the dotty plots; deal with unlimited number of independent and response variables; consider combined multiple threshold criteria, which is subjective depending on the target of the investigation for response variables; and provide a range of values with their distribution for the optimization. [ABSTRACT FROM AUTHOR]

The microwave-assisted extraction (MAE) of antioxidant compounds from mango seeds was optimized using response surface methodology. The important factor influencing antioxidant activity was identified by a Plackett-Burman design, which determined three factors as follows: significant solid liquid ratio (X1), temperature (X2) and extraction cycle (X3), respectively. A Box-Behnken design (BBD) was applied to optimize the significant factors. The optimized conditions are X1 of 1/60 g/mL, X2 of 75 °C, and X3 of 2 cycles. Under these conditions, the antioxidant activity is 1738.2 mg trolox/g. IC50 (0.078 mg/mL), which indicates the phenolic compounds possess an antioxidant activity greater than the commercial antioxidants. RP-HPLC-ESI-MS analysis reveals that ethyl gallate, Penta-O-galloyl-glucoside (PGG) and Rhamnetin-3-[6"-2-butenoil-hexoside] are the major composition in the mango seed extracts. This study revealed that MAE is an efficient method for extracting compounds with relevant biological properties. [ABSTRACT FROM AUTHOR]

An ionic liquid-based microwave assisted extraction (IL-MAE) method was developed for a diterpenoid lactone-andrographolide from Andrographis paniculata by response surface methodology using ionic liquid, 1-butyl-3-methyl-imidazolium chloride ([bmim]Cl). Variable microwave-assisted extraction parameters were selected as concentration of [bmim]Cl, extraction time and microwave power while solid-liquid ratio and extraction temperature were kept constant. Response surface methodology was employed to develop the predictive model for optimization and simulation of the extraction process. A multivariate quadratic regression equation was obtained by central composite design. The 3 D response surface curve and contour plots were obtained by variance of analysis (ANOVA). High performance thin layer chromatography (HPTLC) was performed for quantitative analysis of andrographolide and for comparison of IL-MAE extraction with conventional methods. The optimum extraction conditions were 2.84 mol/L, microwave power 600 W, extraction time 6 min, extraction temperature 70 °C, solid-liquid ratio 1:10. With this novel IL-MAE method, the yield of andrographolide was increased from 1.5% w/w in 7 days (maceration) and 1.8% w/w in 3 h (soxhlation) to 4.71% w/w in 6 min (IL-MAE). At the same time there was reduction in the environmental pollution by using the green solvents/ionic liquids (ILs). [ABSTRACT FROM AUTHOR]

Brönsted acidic ionic liquid was introduced in microwave assisted extraction procedure to simultaneously extract pectin and naringin from the albedo part of pomelo peels. The process for the extraction of pectin and naringin was optimized by a dual response surface methodology. The optimal conditions as follows: [HO 3 S(CH 2 ) 4 mim]HSO 4 concentration of 10 mmol/L, microwave irradiation time of 15 min, liquid–solid ratio of 26 mL/g, and microwave irradiation power of 331 W. Under the optimum conditions, the yields reached to 291.60 ± 7.25 mg/g for pectin and 8.38 ± 0.20 mg/g for naringin. [HO 3 S(CH 2 ) 4 mim]HSO 4 enjoyed excellent solvent effect for the extraction of pectin and naringin in microwave assisted extraction method in comparing with reference solvents. Fourier transform infrared spectroscopy, scanning electron microscope, and atomic force microscope were employed for the characterization analysis of pectin. Interestingly, the pectin extracted with [HO 3 S(CH 2 ) 4 mim]HSO 4 aqueous solution possessed relatively low degree of esterification and rough, hard and network structures which were apparently different with that extracted with hydrochloric acid solution. Additionally, 190.37 ± 3.28 mg naringin with a purity of 95.23% ± 1.3% were gained from 50 g albedo part of pomelo peels and confirmed by nuclear magnetic resonance, Fourier transform infrared spectroscopy, and mass spectroscopy analysis. This study provides a promising paradigm in modern separation science for the extraction of natural products from plant sources. [ABSTRACT FROM AUTHOR]

The aqueous extract of Terminalia chebula Retz. plays an important role in traditional medicinal formulations. Experiments on microwave irradiation during aqueous extraction of flavonoids from T. chebula reveal the influence of microwaves on solid-liquid equilibrium, leading to higher equilibrium flavonoid concentration in the liquid phase at a fixed flavonoid concentration in the solid phase. As a result, microwave assisted extraction (MAE) provided 14.17% enhancement in equilibrium yield, compared to that obtained in conventional extraction at a temperature of 100 °C and a solvent-to-feed ratio of 40 mL/g. The effective diffusion coefficient at 40 mL/g increased from 0.68 × 10 −11 to 1.31 × 10 −11 m 2 /s due to microwave irradiation. Our data conclusively indicates that microwave assisted extraction provides higher yield, equilibrium concentration and effective diffusion coefficient. The study has also revealed the possibility of utilization of MAE for short duration extraction with lower solvent and energy consumption. The extractions were found to be endothermic and spontaneous, with the spontaneity improved due to microwave irradiation. [ABSTRACT FROM AUTHOR]

This review has been written with the objective to strategically screen the published research papers (articles) through Scopus database related to microwave assisted extraction (MAE) of bioactive(s) from plant matrix and present a critical analysis report. Scopus is world's largest abstract and indexing database being used by researchers worldwide. This review discusses the publication trends of articles from 2005–2015 related to the above mentioned theme which shall give the readers a 10 year performance report to what extent MAE has been explored for extraction of botanicals compared to other areas of research in natural products. Based on the article screening some of the widely used domains related to MAE of botanicals and the top three participating countries have been identified. Core concept of strategizing and prioritizing research on MAE of botanicals has been presented in a simplified manner. [ABSTRACT FROM AUTHOR]

Microwave assisted extraction (MAE) is an emerging technique of extraction that improve yields and reduce process time and energy. The aim of this work was to evaluate the effect of different MAE process parameters in the extraction yield of orange peel essential oil (EO), and the description and simulation of this process with mathematical models based on mass transfer fundamentals. For the assessment of process parameters effects on EO yield, different extractions were carried out following a two-level factorial design varying orange peel particle shape (spheres or plaques) and moisture content (dry or not), as well as microwave potency (360 or 540 W). Results demonstrated that particle size, moisture content, and its interaction significantly affected (p < 0.05) the yield obtained and had an influence on the extraction mechanism. Model parameter values associated to mass transfer coefficients (k 1 and k 2 ) indicated that diffusion was the process that defined extraction velocity. [ABSTRACT FROM AUTHOR]

Microwave-assisted solid–liquid extraction (MAE) of flavonoids from Terminalia bellerica Roxb. has been investigated to understand the influence of solvent-to-feed ratio (5–40 mL/g) and temperature (40–100 °C) on kinetics and thermodynamics of extraction. The flavonoid concentration–time data were analysed using a second order kinetic model to determine extraction constant. A diffusion model was utilized to determine diffusion coefficient taking into account of both washing and diffusion phases together. Solvent-to-feed ratio and temperature were observed to show a significant effect on flavonoid yield, extraction rate and effective diffusion coefficient with the highest solvent-to-feed ratio and temperature providing the maximum flavonoid yield of 25.21 mgQE/g using water as the solvent. An empirical equation has been developed to predict extraction kinetics. Thermodynamic parameters revealed MAE process to be spontaneous and endothermic. The kinetic and diffusion models provided valuable insights into the microwave assisted extraction process. T. bellerica was observed to be a good source of flavonoids. Therefore, MAE is a suitable method for extraction of flavonoids from T. bellerica when water alone is to be used as the solvent, as in the case of traditional Indian medicinal preparations. [ABSTRACT FROM AUTHOR]

In this paper, the extraction conditions yielding the highest steviol glycosides from the leaves of Stevia rebaudiana were determined using microwave (MAE) and ultrasonically assisted extraction (UAE) and biological activities of the extracts along with analyses of the residue from the extraction process were investigated. Under optimum conditions, 21.21 mg glycosides/g dried leaf in MAE and 14.90 mg glycosides/g dried leaf in UAE were quantified by HPLC analyses. After extraction, total chlorophyll, carotenoid contents and total dietary fibers were quantified as 15.14 mg/100 g, 2.93 mg/100 g and 6.5% in the raffinate phase. The total phenols were determined as 80.13 and 86.47 mg gallic acid/g extract, whereas the total flavonoids were 111.16 and 126.70 mg quercetin/g extract and DPPH radical scavenging activities were 91.39 and 92.40%, respectively. The extracts exhibited no cytotoxicity against healthy cell line and macrophage RAW 264.7 cells. The IC 50 values were 68 μg/ml and >100 μg/ml for MAE and UAE. Overall, obtained results suggest that stevia extracts and its residue can be utilized holistically on industrial scale. [ABSTRACT FROM AUTHOR]

The influence of the main parameters on extraction of naphthodianthrone pigments (hypericin and pseudohypericin) from raw phytomass Hypericum perforatum using microwave activation was studied. The maximal pigment extraction was found to be achieved when using 55% ethanol or isopropanol as extractants at a water duty of 40 (power density of microwave irradiation was 0.0205 W/cm at a frequency 2450 MHz for 60 s). The microwave-assisted extraction of hypericin and pseudohypericin from H. perforatum was experimentally proved to be a particular example of the mass transfer intensification in a capillary porous body-liquid system. Microwave activation is found to implement extraction by ten times, reducing the time necessary to fully extract the pigments from H. perforatum compared to classical extraction. [ABSTRACT FROM AUTHOR]

Sulfated polysaccharides (fucoidan) from brown seaweed Ascophyllum nodosum were extracted by microwave assisted extraction (MAE) technology. Different conditions of temperature (90–150 °C), extraction time (5–30 min) were evaluated and optimal fucoidan yield was 16.08%, obtained from 120 °C for 15 min's extraction. Compositional analysis, GPC, HPAEC and IR analysis were employed for characterization of extracted sulfated polysaccharides. Fucose was the main monosaccharide of fucoidan extracted at 90 °C while glucuronic acid was the main monosaccharide of fucoidan extracted at 150 °C. Both the molecular weight and sulfate content of extracted fucoidan increased with decreasing extraction temperature. All fucoidans exhibited antioxidant activities as measured by DPPH scavenging and reducing power, among which fucoidan extracted at 90 °C was highest. This study shows that MAE is an efficient technology to extract sulfated polysaccharides from seaweed and Ascophyllum nodosum could potentially be a resource for natural antioxidants. [ABSTRACT FROM AUTHOR]

Microwave-assisted ionic-liquid-impregnated resin solid-liquid extraction was developed for the extraction of triazine herbicides, including cyanazine, metribuzin, desmetryn, secbumeton, terbumeton, terbuthylazine, dimethametryn, and dipropetryn in honey samples. The ionic-liquid-impregnated resin was prepared by immobilizing 1-hexyl-3-methylimidazolium hexafluorophosphate in the microspores of resin. The resin was used as the extraction adsorbent. The extraction and enrichment of analytes were performed in a single step. The extraction time can be shortened greatly with the help of microwave. The effects of experimental parameters including type of resin, type of ionic liquid, mass ratio of resin to ionic liquid, extraction time, amount of the impregnated resin, extraction temperature, salt concentration, and desorption conditions on the extraction efficiency, were investigated. A Box-Behnken design was applied to the selection of the experimental parameters. The recoveries were in the range of 80.1 to 103.4% and the relative standard deviations were lower than 6.8%. The present method was applied to the analysis of honey samples. [ABSTRACT FROM AUTHOR]

The wax present in petroleum sludge, generated by refineries and at crude production sites, consists of paraffin hydrocarbons (C18–C36) known as paraffin wax and naphthenic hydrocarbons (C30–C60). The present study is aimed at the recovery of wax from petroleum oily sludge by microwave-assisted solvent extraction using a Toluene/MEK mixture and subsequently de-crystallizing the wax. The process variables affecting the microwave-assisted solvent extraction are optimized for recovery of wax. The simultaneous effects of process variables such as irradiation time (2–10 minutes), solvent to sludge ratio (40–80 wt%), reactant volume (100–300 ml), and microwave power (80–400 W) on the recovery of wax were evaluated. A central composite design and response surface methodology were used for the optimization of the extraction process. Based on the central composite design, quadratic models were developed to correlate the extraction process variables with the responses and the models were analyzed using appropriate statistical methods for analysis of variance. Optimization of process variables shows the maximum recovery of wax was about 79.57% at 300 ml of reactant volume with microwave power output of 400 W at 7.6 minutes of retention time with 56.56% of Toluene/MEK to sludge ratio. [ABSTRACT FROM AUTHOR]

The process of microwave assisted extraction of antioxidants extract fromGarcinia pedunculataRobx. was optimized using response surface methodology. A Box-Behnkem design was used to investigate the effects of three independent variables, namely solvent concentration(%), solvent to sample ratio(v/w), and radiation time(min) on total antioxidant activity by DPPH and ABTS radical scavenging activity. Optimal conditions for extraction of antioxidants concluded that the solvent concentration be 70.79%, solvent to sample ratio be 20:1, and irradiation time at 4.73 minutes. However, the antioxidant activity of the extract was found to reach upto 85.98% DPPH radical scavenging activity and 19.23 mg-trolox equivalent/g dry weight. FTIR study revealed that, the extraction of antioxidant extract was higher with increase in irradiation time, but the antioxidant activity of the extract was lower with increase in time. The structural changes in plant material after extractions observed by light microscopy provided visual evidence of the disruption effect. [ABSTRACT FROM PUBLISHER]

The effect of particle size on the extraction of tannins by microwave assisted extraction (MAE) was studied for the first time to our knowledge. Maritime pine ( Pinus pinaster ) bark from the South West of France was sieved into five ranges of particle size before extraction was carried out in an ethanol–water solution. For each extraction, the extraction yield, the total polyphenolic content, the condensed tannins content, and the sugar content were quantified. The extracts were characterized by their reactivity to formaldehyde, Fourier transformed infrared spectroscopy (FTIR), 1 H NMR, and heteronuclear single correlation spectroscopy 2D NMR (HSQC 2D NMR). The MAE was also compared to a hot water based extraction. The effect of the particle size on the extraction efficiency was studied. The HSQC 2D NMR revealed that (epi) catechin, epicatechin gallate, epigallocatechine, and epigallocatechine gallate were obtained. Higher amounts of condensed tannins, sugars, and simple flavonoids were extracted by MAE extraction. [ABSTRACT FROM AUTHOR]

Researchers have shown that techniques such as microwave-assisted extraction, ultrasound-assisted extraction, pressurized liquid extraction, and supercritical fluid extraction developed for extraction of valuable components from plants and seed materials have been successfully used to effectively reduce the major shortcomings of the traditional method such as Soxhlet extraction. These include shorter extraction time, increase in yield of extracted components, decrease in solvent consumption, and improvement of the quality of extracts. This review presents a detailed description of the principles and mechanisms of the various extraction techniques for better understanding and summarizes the potential of these techniques in the extraction of oil from plants and seed materials. Discussions on some of the parameters affecting the extraction efficiency are also highlighted, with special emphasis on supercritical fluid extraction. A comparison of the performance of traditional Soxhlet extraction with that of other extraction techniques is also presented. [ABSTRACT FROM AUTHOR]

Abstract: Detection of basal stem rot (BSR) by Ganoderma of oil palms was based on foliar symptoms and production of basidiomata. Enzyme-Linked Immunosorbent Assays-Polyclonal Antibody (ELISA-PAB) and PCR have been proposed as early detection methods for the disease. These techniques are complex, time consuming and have accuracy limitations. An ergosterol method was developed which correlated well with the degree of infection in oil palms, including samples growing in plantations. However, the method was capable of being optimised. This current study was designed to develop a simpler, more rapid and efficient ergosterol method with utility in the field that involved the use of microwave extraction. The optimised procedure involved extracting a small amount of Ganoderma, or Ganoderma-infected oil palm suspended in low volumes of solvent followed by irradiation in a conventional microwave oven at 70°C and medium high power for 30s, resulting in simultaneous extraction and saponification. Ergosterol was detected by thin layer chromatography (TLC) and quantified using high performance liquid chromatography with diode array detection. The TLC method was novel and provided a simple, inexpensive method with utility in the field. The new method was particularly effective at extracting high yields of ergosterol from infected oil palm and enables rapid analysis of field samples on site, allowing infected oil palms to be treated or culled very rapidly. Some limitations of the method are discussed herein. The procedures lend themselves to controlling the disease more effectively and allowing more effective use of land currently employed to grow oil palms, thereby reducing pressure to develop new plantations. [Copyright &y& Elsevier]

A total sample-preparation and analysis time of 50 min is required for the high-throughput method of hair analysis proposed in this paper. The method is applicable to analysis of drugs commonly used in Asia, and their metabolites-methamphetamine (MA), amphetamine (AMP), methylenedioxymethamphetamine (MDMA), methylenedioxyamphetamine (MDA), ketamine (K), norketamine (NK), dehydronorketamine (DHNK), 6-acetylmorphine (6-AM), morphine (MOR), and codeine (COD). Cut and weighed hair (10 mg) was incubated for 3 min with methanol-trifluoroacetic acid (TFA) during microwave-assisted extraction (MAE) at 700 W. The incubation solution was evaporated, the residue was reconstituted in deionized water-methanol, 99:1 ( v/ v), and 20 μL was injected on to a core-shell column (50 × 4.6 mm, 2.6 μm particle size) for liquid chromatographic-tandem mass spectrometric (LC-MS-MS) analysis. Gradient elution separation was performed in 8 min at a flow rate of 1 mL min. No signal interfering with any of the analytes was found in fourteen blank hair samples from different sources. The limits of detection and quantification were 0.5 pg mg and 2.0 pg mg, respectively, for MA, AMP, MDMA, MDA, K, NK, and DHNK, and 2.0 pg mg and 5.0 pg mg, respectively, for 6-AM, MOR and COD. The linear range was between the LOQ and 1000 pg mg, and the correlation coefficients were all greater than 0.999. Investigation of matrix effects revealed that all the analytes were suppressed by less than 20 % and the standard deviation (SD) was always less than 7 %. Recovery was always greater than 90 % and the SD for each compound was less than 6 %. Precision and accuracy for each analyte were within 15 %. Eight authentic hair specimens from known drug abusers were successfully analyzed. Compared with traditional overnight incubation methods, the rapid 3-min extraction time achieved similar or greater extraction yields. Sample preparation by MAE was a reliable procedure for extraction of the analytes from hair but substantially simpler and faster than other methods. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Highlights: [•] The feasibility of sequential Microwave Assisted Extractions of SCG is shown. [•] Five sequential MAE allows the exhaustive recovery of galactomannans (GM). [•] GM is recovered in MAE3 and mannans are obtained in MAE4 and MAE5. [•] Shorten polysaccharides are obtained with increasing of the number of extractions. [•] The un-extracted insoluble material (MAE5R) is composed mainly by cellulose (84%). [ABSTRACT FROM AUTHOR]

Microwave-assisted extraction of sixteen polycyclic aromatic hydrocarbons and their gas chromatographic mass spectrometric detection are presented herein. An efficient extraction was achieved in 15 minutes using 10 mL of 1:1 n-hexane-acetone while a clean-up step was developed studying the elution curves on solid phase extraction silica cartridges. The analytical method was optimized and validated using a certified reference marine sediment; satisfactory figures of merit were obtained with limits of detection in the range 0.001–0.004 µg/g, precision within 6%, and good linearity (regression coefficients generally higher than 0.998, in the concentration range 0.010–1.000 µg/mL). The developed method was successfully applied to the determination of polycyclic aromatic hydrocarbons in real marine sediments collected in two coastal areas of Italy exposed to different anthropic impact: three tourist sites of Liguria and the Venetian Lagoon. The total concentration of the analytes in the samples was in the range 1.027–3.827 µg/g and the use of common markers suggested their probable pyrolytic origin. [ABSTRACT FROM PUBLISHER]

Abstract: Focused-ultrasound solid–liquid extraction was developed for the extraction of polybrominated diphenyl ethers in vegetables and amended soil. Firstly, solid-phase extraction clean-up using 2g and 5g of Florisil and 2-g silica cartridges were evaluated and elution profile was also optimised. Similar recoveries were obtained for most compounds while better recoveries were obtained for 5-g Florisil in the case of the heavier PBDEs. FUSLE extraction time (2min) guaranteed quantitative extraction of the target analytes in the four studied matrices (69–130%). Method detection limit values were in the range of 1–5ngg−1 for splitless injection in a gas chromatograph coupled to a mass spectrometer and no significant improvement was obtained for large volume injection. Relative standard deviation values were between 1% and 30%. Recoveries obtained using FUSLE were compared with those obtained with microwave assisted extraction and the developed method was also applied to a certify reference material of polybrominated diphenyl ethers and polychlorinared biphenyls in sediment. Similar values were obtained in the case of carrot and pepper matrices (77–130% for FUSLE and 77–112% for MAE). However, MAE provided extraction recoveries higher than 100% for most of the BDE congeners in lettuce and amended soil. [Copyright &y& Elsevier]

[Objective] To explore the method of microwave assisted extraction technology of shikimic acid in star anise. [Methods] Using single factor experiment with orthogonal experiment method, to optimize the extraction conditions for studying the effect of different factors on the shikimic acid extraction rate. [Results] The best technology of microwave extract anise shikimic acid is material liquid ratio of 1:20 (g/mL), under the condition of temperature of 65 °C for 10 min, power 400 W, the anise shikimic acid content is 37.45 g/mg. [Conclusions] the method of microwave assisted extraction technology is provided with advantages as simple operation, high extraction efficiency, repeatability is good and is worthy application. [ABSTRACT FROM AUTHOR]

Highlights: [•] Recovery of natural pectin was extracted from waste Citrullus lanatus fruit rinds. [•] Box–Behnken design was applied to study interactive effects of process variables. [•] Microwave irradiation causes the disruptions of cell walls of the plant material. [•] MAE showed high extraction efficiency within shortest extraction time. [•] Optimal conditions were determined by Derringer's desired function methodology. [ABSTRACT FROM AUTHOR]

Highlights: [•] The extraction of polyphenolics from grape residues was optimized for the production of wood adhesives. [•] The study was performed using microwave activation and response surface methodology. [•] The microwave assisted extractions gave higher yields as compared to traditional extraction. [ABSTRACT FROM AUTHOR]

Highlights: [•] Microwave assisted extraction of flavonoids from cultivated E. sagittatum was optimized for the first time. [•] The mechanism underlying microwave assisted extraction was studied. [•] Flavonoid extracts obtained by microwave assisted extraction exhibited relatively high antioxidant activities. [•] Chemical composition of flavonoids extracted by various extraction methods was analyzed. [Copyright &y& Elsevier]

Highlights: [•] Natural pectin was extracted from orange peel by MAE. [•] Box–Behnken design was applied to study interactive effects of process variables. [•] Optimal conditions were determined by Derringer's desired function methodology. [•] Second order polynomial regression models were developed. [•] Experimental values showed good agreement with the predicted values. [ABSTRACT FROM AUTHOR]

An analytical method using microwave-assisted extraction (MAE) and liquid chromatography (LC) with fluorescence detection (FD) for the determination of ochratoxin A (OTA) in bread samples is described. A 2 orthogonal composite design coupled with response surface methodology was used to study the influence of MAE parameters (extraction time, temperature, solvent volume, and stirring speed) in order to maximize OTA recovery. The optimized MAE conditions were the following: 25 mL of acetonitrile, 10 min of extraction, at 80 °C, and maximum stirring speed. Validation of the overall methodology was performed by spiking assays at five levels (0.1-3.00 ng/g). The quantification limit was 0.005 ng/g. The established method was then applied to 64 bread samples (wheat, maize, and wheat/maize bread) collected in Oporto region (Northern Portugal). OTA was detected in 84 % of the samples with a maximum value of 2.87 ng/g below the European maximum limit established for OTA in cereal products of 3 ng/g. [ABSTRACT FROM AUTHOR]

Abstract: For the first time, a novel one-step sample preparation method that combines microwave assisted extraction and solvent bar microextraction (MAE–SBME) with analysis by gas chromatography–mass spectrometry (GC–MS), was developed for the fast and efficient determination of polycyclic aromatic hydrocarbons (PAHs) in environmental soil samples. An interesting feature of the new procedure is that SBME was conducted simultaneously with MAE. Thus, the extract from the SBME could be directly and immediately analyzed by GC–MS. A separate clean up and/or preconcentration process, such as time-consuming and tedious gel permeation chromatography, solid-phase extraction, filtration, or adsorption chromatography, normally associated with conventional MAE, was not necessary. It is also notable that the procedure was environmentally benign since water was used as the extraction solvent in MAE, and only several microliters of organic solvent were used in SBME. Some factors affecting the extraction were studied and optimized. Under the most favorable conditions, the method showed good linearities (between 0.2 and 500, 0.5 and 500, 1 and 500, and 2 and 500ng/g, depending on the analytes), low limits of detection (from 0.03 to 0.25ng/g), and satisfactory precision (with relative standard deviations below 9.8%). The MAE–SBME procedure provides a fast and simple sample preparation approach for the processing of environmental soil samples. [Copyright &y& Elsevier]