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Based on a modification of normal hydrothermal synthesis, uniform and spherical mesoporous siliceous particles (MSP) were prepared and applied to high-performance size exclusion chromatography (HPSEC). Sodium acetate buffer solution at pH = 4.0 was the optimal mobile phase for the separation of the three biomacromolecular polysaccharides (alginic acid, fucoidan, and laminarin) in the MSP-based HPSEC. Based on the optimal separation conditions, the calibration curves of the three polysaccharide standards showed good linearity (R2 > 0.999). In addition, the limits of detection of the three standards ranged from 0.02 to 0.13 mg mL−1, the limits of quantitation ranged from 0.07 to 0.43 mg mL−1, the related recoveries were 97.7–101.2%, and the relative standard deviations of the retention time were 0.2–0.5. All the quantitative parameters showed that the developed approach was suitable for quantifying biomacromolecular polysaccharides. Compared to a common commercial HPSEC column, the MSP-based HPSEC column was low cost and had a similar separation efficiency for the three polysaccharides. In particular, 2.8 mg g−1of the alginic acid fractions, 4.4 mg g−1of the fucoidan fractions, and 6.9 mg g−1of the laminarin fractions were separated from theThallus Laminariaeextracts by MSP-based HPSEC. Similar results were obtained from the commercial HPSEC. [ABSTRACT FROM AUTHOR]

Enzymatic hydrolysis, which is one of the steps in the production of bioethanol, is a major process in the degradation of polysaccharides. Enzyme-immobilized technology has been developed because enzymes can be contaminated easily and are difficult to reuse. In this study, β-glucanase was immobilized on silica, and the effects of the enzyme-silica size, time, temperature, and amount of enzyme-silica on the hydrolysis of polysaccharides in the Chamaecyparis obtusa residue were studied. The enzyme-silica size, time range, temperature, and amount of enzyme-silica studied ranged from 10 to 63 µm, 2 to 12 hr, 25 to 45°C, and 0.05 to 0.25 g, respectively. The optimal enzyme-silica size, time range, temperature, and amount of β-glucanase immobilized on enzyme-silica for the hydrolysis of polysaccharides were found to be 10–25 µm silica, 10 hr, 40°C, and 0.15 g, respectively. The enzyme could not be used at temperatures higher than 40°C due to denaturation. Under the optimal conditions, the glucose yield was 12.77 mg/mL. [ABSTRACT FROM AUTHOR]

This paper reports the extraction of two phenolic acids fromHerba Artemisiae Scopariaeusing deep eutectic solvents that were synthesized with various salt and hydrogen bond donors. The optimal conditions were found to be 50% of a synthesized deep eutectic solvent from tetramethyl ammonium chloride and urea (1:4) mixed with methanol/water (60:40,v/v). Phenolic acid extraction was optimized using an ultrasonic power of 89 W for 30 min with a solid/liquid ratio of 1:10. Under the optimized conditions, good calibration curves were observed at phenolic acid concentrations ranging from 10.0 to 500.0 µg/mL. The method recovery ranged from 97.3% to 100.4%, and the inter-day and intra-day relative standard deviations were less than 5%. Under the optimal extraction conditions, the amounts of chlorogenic acid and caffeic acid extracted fromHerba Artemisiae Scopariaewere 9.35 mg/g and 0.31 mg/g, respectively. [ABSTRACT FROM PUBLISHER]

The extraction of valuable compounds from waste products using green and inexpensive solvents is a significant strategy for sample preparation. Accordingly, in the present study, the use of deep eutectic solvents, an emerging green approach, was used to extract astaxanthin, a well-known and widely-used antioxidant, from shrimp byproducts. After evaluating different combinations of extraction conditions and deep eutectic solvents, an ultrasonication method was established and optimized by a systematic investigation of the influencing factors. A comparison of the amount of astaxanthin (102 μg g− 1) extracted using a traditional organic solvent, ethanol, showed that more astaxanthin (146 μg g− 1) was obtained using the reported eco-friendly method. The excellent properties of deep eutectic solvents highlight their advantages as promising inexpensive green solvents for the extraction and determination of a range of bioactive compounds from natural products. [ABSTRACT FROM AUTHOR]

A sensitive determination method was developed for the analysis of pyrethroid pesticide residues in tomato samples using ionic liquid-based dispersive liquid–liquid microextraction. A hydrophobic ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) and acetonitrile were used as the extraction solvent and dispersive solvent, respectively. The following experimental parameters affecting the extraction efficiency were examined: types of extraction solvent and volume of extraction solvent, types of dispersive solvent and volume of dispersive solvent and pH and ion strength of the sample solution. Under the optimum conditions, the extraction recoveries ranged from 83.9 to 96.7%. Moreover, the enrichment factors for esbiothrin, fenpropathrin and cyhalothrin were 42, 48 and 45, respectively. The calibration curves were linear with correlation coefficients ranging from 0.9997 to 0.9999 at concentrations of 0.05–1.5 µg/kg. The relative standard deviation (n = 5) was 1.7–4.5%. The limits of detection for esbiothrin, fenpropathrin and cyhalothrin were 8.1, 9.9 and 14.3 µg/kg, respectively. [ABSTRACT FROM AUTHOR]

Headspace single-drop microextraction (HS-SDME) was used to extract five terpenoids (α-terpinene, γ-terpinene, linalool, α-terpineol, and terpinyl acetate) from powderedChamaecyparis obtusaleaves. The terpenoids were determined by gas chromatography with flame ionization detection. Under the optimized conditions, oleyl alcohol efficiently extracted the analytes from the leaves within 20 min at 100°C. The results showed that the amounts of α-terpinene, γ-terpinene, linalool, α-terpineol, and terpinyl acetate extracted from the samples were 2.19, 3.68, 0.11, 0.87, and 22.35 µg/g, respectively. Compared to microextraction of the compounds from the sample solution, the new technique had fewer steps. The method also had similar extraction properties as heat reflux extraction, but required a smaller sample volume and less time. [ABSTRACT FROM AUTHOR]

Three ionic liquid (IL)-modified porous polymers were synthesized and used for the adsorption of lactic acid. The experimental adsorption kinetics and equilibrium data from the IL-modified polymers were obtained. The kinetic study revealed a low temperature to be advantageous to the adsorption process. The dependence of the level of lactic acid adsorption on the amount of polymer, initial lactic acid concentration, and pH was examined at equilibrium. The maximum efficiency was obtained using the maximum adsorbent dose. A comparison of lactic acid adsorption at different pH revealed anion exchange to be the main interaction between the lactic acid and polymers, not molecular adsorption. The amounts adsorbed were fitted to the Langmuir, Freundlich, and Temkin equations. The equilibrium data for modified polymers (imidazole modified polymer, methylimidazole modified polymer, and ethylimidazole modified polymer) were best represented by the Langmuir and Freundlich isotherm with R2 values of 0.99. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

The gas chromatographic analysis of fatty acids has attracted considerable interest. In this analysis, the common derivatives of fatty acids, such as fatty acid methyl esters, can be detected using a flame ionization detector and the mass spectra can indicate the true structure of fatty acids. This paper reviews gas chromatographic methods for obtaining fatty acids from marine organisms. The stationary phase and detector for applications in gas chromatography are discussed. This article also reviews the components of fatty acids in marine animals, marine plants and marine microorganisms. [ABSTRACT FROM AUTHOR]

Antarctic krill crude extracts contain high levels of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Accordingly, the solid phase extraction of EPA and DHA from Antarctic krill crude extracts has attracted significant research interest. This study compared the extraction of EPA and DHA from Antarctic krill crude extracts using an aminopropyl, zinc ion-doped silica, and C18 and zinc ion-doped C18 solid-phase column. The best extraction effect was obtained using the zinc ion-doped C18 SPE with water containing methanol as the eluant. The efficiency increased gradually with increasing methanol concentration from 12.5 to 25% in the washing stage, and when pure methanol (5.0 mL) or acetonitrile (3.0 mL) was used as the eluant. To detect EPA and DHA, the acids were first converted to their methyl esters and detected by gas chromatography with flame ionization detection (GC–FID). In the zinc ion-doped C18 elution fractions, EPA and DHA were isolated from the crude extracts in high yield (85–91% (r2 = 4.8–6.3%)). [ABSTRACT FROM AUTHOR]

Carbendazim (CBZ) is widely used for crop protection and its residues threaten human health and the environment. Therefore, developing an effective electrocatalyst is important for the extremely sensitive detection of CBZ. Lattice-strain engineering is an effective strategy to change its electronic structure and ultimately optimize the catalytic performance of materials, which can be used as a modification method to improve the detection performance of electrochemical sensors. Herein, a NiFeLDH@HsGY-NH 2 /MWCNTs heterojunction with strain effect is prepared by the electrostatic self-assembly method. The structure, morphology, composition, crystallinity and electrochemical performance of NiFeLDH@HsGY-NH 2 /MWCNTs are analyzed using various instrumental techniques, in which geometric phase analysis (GPA) and X-ray diffraction (XRD) images confirm the lattice-strain generated in NiFeLDH@HsGY-NH 2 /MWCNTs. The results indicate that the prepared electrochemical sensor exhibited an excellent response for carbendazim (CBZ) in the linear range of 0.05-50.00 μM with a detection limit of 10.00 nM ( S / N = 3) under the optimal detection conditions. By analyzing the reasons for the improvement of the catalytic performance of the composite material, it is found that the composite of MWCNTs not only improves the conductivity of NiFeLDH but also regulates the electronic structure of metal atoms through double effects. This study provides new insights into the design of efficient and low-cost catalysts to facilitate electrochemical sensor applications.

Three flavones (quercetin, myricetin and amentoflavone) were extracted from Chamaecyparis obtusa leaves using deep eutectic solvents (DESs) as additives to conventional extractions solvents. Sixteen DESs were synthesized from different salts and hydrogen bond donors. In addition, C. obtusa was extracted under optimal conditions of methanol as the solvent in the heating process (60°C) for 120 min at a solid/liquid ratio of 80%. Under these optimal conditions, a good linear relationship was observed at analyte concentrations ranging from 5.0 to 200.0 μg/mL (R(2) > 0.999). The extraction recovery ranged from 96.7 to 103.3% with the inter- and intraday relative standard deviations of <4.97%. Under the optimal conditions, from C. obtusa, the quantities of quercetin, myricetin and amentoflavone extracted were 325.90, 8.66 and 50.34 µg/mL, respectively. Overall, DESs are expected to have a wide range of applications., (© The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)