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Our study aimed to optimize carob antioxidant extraction for use in the food, cosmetic, and pharmaceutical industries. Maceration investigated ethanol concentration, extraction temperature, and time, while ultrasound-assisted extraction examined ethanol concentration, ultrasound power, and time. A central composite design with 19 experimental points assessed the influence of variables on total yield, total phenolic content, and antioxidant activity. The results were analyzed to optimize the extraction parameters and enhance the antioxidant extraction from carob. The results of the study show that the best maceration condition for extracting antioxidants from the plant material was found to have a time of 24.38 minutes, an ethanol content of 59.02%, and a temperature of 54.52°C. Similarly, the optimal conditions for ultrasound-assisted extraction were found to be 51.49 minutes, 79.78% sonication power, and 76.12% alcohol. The optimal conditions identified can be used as a starting point for further optimization and scaling up of the extraction process. [ABSTRACT FROM AUTHOR]

In analytical chemistry, the synergy between innovative sample preparation techniques and advanced chromatographic methods has paved the way for unprecedented advancements in the analysis of complex samples. Solid Phase Microextraction (SPME) stands out as a powerful tool for extraction, and preconcentration. When coupled with High-Performance Liquid Chromatography (HPLC) equipped with a Diode Array Detector (DAD), the integrated SPME-HPLC-DAD system emerges as a sophisticated analytical platform, offering enhanced sensitivity, selectivity, and versatility for various applications. Desorption is accomplished by either depositing organic solvent in the desorption chamber or else by flowing the mobile phase through the desorption chamber specificity. An ordinary description, along with a visual illustration, has been thoroughly provided for concepts of developed well-known enhanced thin film SPME cartridges (Figure 2). The tabular representation is also available with proper description like technique name, targeted analyte, column used, mobile phase used, %RSD, extraction recovery, LOD, and data acquired R2 also considered Based on the information available in the present study. Discussed SPME with HPLC-DAD brings a great turning point by successfully utilization in biomedical sciences, environmental monitors, food safety, and clinical analysis This cost-effective, readily available technique is both environmentally friendly and stable, allowing for rapid, reliable, and accurate measurements across a wide range of analyte concentrations, thanks to the utilization of hyphenated techniques. The different strategies of SPME with HPLC -DAD and possible future apllications have been incorporated in the review. The understanding of these techniques is still limited and challenging. [ABSTRACT FROM AUTHOR]

Achieving grain refinement in the wire-arc directed energy deposition (DED) process of NiTi alloy is highly challenging. We have successfully obtained NiTi alloy with a fine microstructure and observed an improvement in superelastic recoverability by introducing an ultrasound-assisted field during the deposition process. The results show that the average grain size of the NiTi alloy samples decreased from 147.3 to 72.2 µm. Additionally, the recoverable strain of the samples increased significantly from 3.7% to 4.4%. This is attributed to the ultrasonic cavitation and acoustic streaming phenomena during the ultrasound-assisted process, which promotes the columnar-to-equiaxed transition (CET) during the solidification process. Fundamentally, the key to the enhancement of recoverable strain after ultrasound-assisted is that the formation of equiaxial grains provides more strain compatibility to the grain boundaries, which reduces the formation of dislocations during deformation. [ABSTRACT FROM AUTHOR]

The Green, delicate and rapid ultrasound-assisted ionic liquid-based dispersive liquid-liquid microextraction technique was developed to preconcentrate trace quantities of zirconium Zr(IV) ion in real samples prior to spectrophotometric detection. The proposed method uses (1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate) ionic liquid (IL) as an extraction solvent for Zr(IV) ions after the complexation with quinalizarin at pH 5.0. The effect of various analytical parameters has been investigated. The calibration graph was linear in the range of 2.0–400 µg L − 1 and the limit of detection was 0.6 µg L-1. The preconcentration factor was 100. Relative standard deviation (RSD%) at 200 µg L-1 of Zr(IV)for intra-day and inter-day precisionwere 2.0 and 2.7%, respectively (n = 10). Certified reference materialswere used to verify the accuracy.The proposed method was applied to preconcentrate and determine the content of Zr(IV) in real environmental (water, soil and plants) samples with satisfactory results. [ABSTRACT FROM AUTHOR]

An environmentally friendly, sensitive, easy and fast ultrasound-assisted ionic liquid-based dispersive liquid-liquid microextraction technique (UA-IL-DLLME) was developed to preconcentrate trace quantities of nickel Ni(II) ion in water, food and tobacco samples prior to detection by FAAS. The proposed technique based on utilisationthe of ionic liquid (IL) (1-hexyl-3-methylimidazolium tris(pentafluoroethyl)trifluorophosphate [HMIM][FAP]) as an extraction solvent for Ni(II) ions after the complexation with quinalizarin (Quinz) at pH 6.0. The impact of different analytical parameters on the microextraction efficiency was investigated. In the range of 2.0–300 µg L−1, the calibration graph was linear. Limit of detection and preconcentration factor were 0.6 µg L−1 and 100. Relative standard deviation (RSD%) as precision at 50 and 100 µg L−1 of Ni(II) were 2.4% and 3.6%, respectively (n = 10). The validation of the proposed procedure was verified by a test of two certified reference materials (TMDA-51.3 fortified water, TMDA-53.3 fortified water and SRM spinach leaves 1570A) applying the standard addition method. Finally, the proposed UA-IL-DLLME method was developed and applied to preconcentrate and determine of trace quantities of Ni(II) in real water, food and tobacco samples with satisfactory results. [ABSTRACT FROM AUTHOR]

In this work, optimized techniques of conventional, ultrasound and microwave-assisted extraction were applied for the recovery of antioxidant compounds from lemon by-products (Citrus limon L). Specifically, the effect of solvent, temperature, microwave power, time and their interaction on the extraction was investigated. Among the tested solvents, the hydroalcoholic mixture (ethanol:water, 50:50) was the optimal one for all extraction techniques: in particular assisted by ultrasounds at 70 °C for 30 minutes (total phenolic content: 6.93 mg GAE g−1, total flavonoids: 2.07 mg CE g−1, ABTS assay: 18.36 µM TE g−1). Also, the other techniques allowed to obtain valuable extracts, although with relative lower amounts. The analyses of individual phenols revealed hesperidin and eriocitrin as the main compounds (respectively about 1650 and 1150 mg kg−1) after ultrasound assisted and conventional extraction. Results of this work can be useful to valorize an industrial by-product by sustainable techniques for the high-added value substances recovery. [ABSTRACT FROM AUTHOR]

Synthesis of ethyl acetate (EA) using lipase as a catalyst, as an environmentally-friendly process, has attracted considerable attention. However, the slow rate of enzymatic reaction and higher cost limit its applications. Ultrasound irradiation (UI) is known as an effective tool for accelerating the rate of enzymatic reaction under mild conditions. To attain maximum yield, it is crucial to understand the effect of UI on EA synthesis and the underlying mechanism. Therefore, the present study investigated the effect of UI on lipase-catalyzed ethyl acetate synthesis. The results clearly demonstrated that UI could remarkably accelerate the process of lipase-catalyzed synthesis of ethyl acetate compared with mechanical shaking. The optimal conditions of ultrasound-assisted reaction by using Novozyme 435® were 6% enzyme loading, 4:1 molar ratio of ethanol to acetic acid, 150 W & 28 kHz ultrasonic power and frequency, respectively. Bi-bi ping-pong model was employed to give a deep insight into the underlying mechanism of the beneficial effect of UI. It was found that Vmax under UI was elevated by 143% compared with that under mechanical shaking. Application of UI could decrease Kacetic acid and Ki ethanol while increase Kethanol and Ki acetic acid. In conclusion, the present study addresses that UI could remarkably accelerate the process of lipase-catalyzed synthesis of EA compared with mechanical shaking, and kinetic model results explained why ultrasound can significantly speed up lipase catalyzed synthesis of ethyl acetate, which may help to improve the industrial application potential of ethyl acetate biosynthesis. [ABSTRACT FROM AUTHOR]

Unburnt coal in a boiler gets converted to fly ash and bottom ash. Fly ash particles travel along with flue gas and get deposited on heat transfer surfaces along the way. Fouling and slagging are phenomena associated with fly ash deposits which could potentially damage the heat transfer surface, if left unattended. Sodium and potassium are directly linked to the deposition of fly ash, as they form a molten salt film which aids in sticking of fly ash particles. Ultrasound is one of the mitigation techniques used to prevent ash deposition. This study aims at reducing the concentrations of alkali metals in coal as a pretreatment method, using ultrasound. Two modes of operation are chosen: continuous and pulsed. A solvent has been used to enhance the leaching process. In the pulsed mode, the sample is alternated between periods of exposure and nonexposure. A maximum leaching rate of 62% for potassium and 24.5% for sodium was observed in the continuous mode at 360 kHz of operation while pulsed mode of operation showed a maximum leaching rate of 91.3% and 54.4% for potassium and sodium operated at 360 kHz, respectively. The experimental data have been fit to the shrinking core model, and the rate-controlling step has been found to be surface diffusion of reactants into the core. The effect of various parameters is analyzed and compared for pulsed and continuous modes of operation. Order of the reaction, activation energy, and leaching kinetics are obtained by fitting the data into the shrinking core model. [ABSTRACT FROM AUTHOR]

The distribution state and occurrence form of impurities of rice husk ash were analyzed and identified by SEM/EDS and XRD. The reaction kinetics for the leaching phosphorus have been studied to determine the effect of process parameters, such as stirring speeds, temperatures, HCl concentrations, particle sizes, ultrasound powers and frequencies. The kinetic data fit a new transformation of shrinking core model. The apparent activation energy is 81.21 kJ/mol. And the reaction orders with reference to HCl concentrations, particle sizes, ultrasound powers and frequencies are determined to be 2.54, −0.59, 1.55 and −0.92, respectively. The semi-empirical equation is as follows: [ABSTRACT FROM PUBLISHER]

The effects of ultrasound-assisted, supercritical CO2and solvent extraction methods on antioxidant activity ofZiziphus mauritiana(Lam.) extracts were investigated using 2,2-diphenyl-1-picrylhydrazyl and β-carotene assays. Ethanol-water extract of the jujube that was obtained with ultrasound-assisted extraction had the highest antioxidant activity. Ultrasound-assisted extraction was the most effective method on extraction of phenolic compounds. The effect of ultrasound extract in stability of soybean oil was compared to synthetic antioxidants by measuring total polar compounds, carbonyl value, peroxide value, free fatty acids, oxidative stability index, and conjugated dienes and trienes values. Results showed that ultrasound ethanol-water extract at 600 ppm had a higher stabilization efficiency than commercial antioxidants butylated hydroxyanisole, butylated hydroxytoluene, and tertiary butylhydroquinone. [ABSTRACT FROM PUBLISHER]

A simple and rapid ultrasound-assistedin situsorbent formation solid-phase extraction (UAISFSPE) coupled with electrothermal atomic absorption spectrometry detection (ET-AAS) was developed for preconcentration and determination of arsenic (As) in various samples. A small amount of cationic surfactant is dissolved in the aqueous sample containing As ions, which were complexed by ammonium pyrrolidinedithiocarbamate After shaking, a little volume of hexafluorophosphate (NaPF6) as an ion-pairing agent was added into the solution by a microsyringe. Due to the interaction between surfactant and ion-pairing agent, solid particles are formed. The alkyl groups of the surfactant in the solid particles strongly interact with the hydrophobic groups of analytes and become bound. Sonication aids the dispersion of the sorbent into the sample solution and mass transfer of the analyte into the sorbent, thus reducing the extraction time. The solid particles are centrifuged, and the sedimented particles can be dissolved in an appropriate solvent to recover the absorbed analyte. After separation, total arsenic (As(III) and As(V)) was determined by ET-AAS. Several experimental parameters were investigated and optimized. A detection limit of 7 ng L−1with preconcentration factor of 100 and relative standard deviation for 10 replicate determinations of 0.1 µg L−1As(III) were 4.5% achieved. Consequently, the method was applied to the determination of arsenic in certified reference materials, water, food and biological samples with satisfactory results. [ABSTRACT FROM AUTHOR]

Solvent extraction, ultrasound assisted extraction (UAE), and microwave assisted extraction (MAE) were examined for the extraction of astaxanthin from Haematococcus pluvialis. In all cases, acetone was found to give the highest astaxanthin recovery compared with other selected solvents, i.e., methanol, ethanol, and acetonitrile. Among the various methods, MAE at 75°C for 5 min resulted in the highest astaxanthin recovery (74 ± 4%). [ABSTRACT FROM AUTHOR]