Ardeshir Shokrollahi; Samira Hessampour
Abstract
In this paper, the Taguchi orthogonal design was applied to optimize the extraction efficiencies for the determination of curcumin, after the separation and preconcenteration by supramolecular based-ultrasonic assisted-dispersion solidification liquid-liquid microextraction (SM-UA-DSLLME) procedure coupled ...
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In this paper, the Taguchi orthogonal design was applied to optimize the extraction efficiencies for the determination of curcumin, after the separation and preconcenteration by supramolecular based-ultrasonic assisted-dispersion solidification liquid-liquid microextraction (SM-UA-DSLLME) procedure coupled with spectrophotometric UV-Vis. The experimental design consisted of six parameters (pH, amount of the extraction and disperser solvents, salt effect, sonication time and centrifuge time), each at five levels. The preconcentration method is based on the dispersion-solidification liquid-liquid microextraction of curcumin with decanoic acid/THF as the supramolecular solvent (a nano-structured liquid occurring on two scales, molecular and nano). The purpose method had two linear ranges of 0.01–0.40 and 0.40-3.50 mg L−1 of curcumin with R2= 0.9922 and 0.9799, respectively. The enrichment factors of 478.48 and 118.80 were obtained for down and up linear ranges, respectively. The preconcentration factor under consideration recovery was obtained 46. Detection limit was 5.2 µg L−1 and the relative standard deviation (RSD%), for eight replicate measurements of 0.2 mg L−1 curcumin was 2.47%. The results obtained from the analysis of variance (ANOVA), revealed that the most important effectible parameters onextraction curcumin are volume of disperser solvent and pH. The applicability of method was successfully applied to determine of trace curcumin in tablet, sewage and water samples.
Forough Karami; Ardeshir Shokrollahi; Razie Razavizade
Abstract
A precipitation method was used to synthesize MCM-41. Then, the obtained mesoporous was modified using layered double hydroxide (MCM-41@LDH). The novel mesoporous MCM-41@LDH was successfully applied for adsorption of lysozyme (LYS) at different conditions such as adsorbent amount, pH of solution, stirrer ...
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A precipitation method was used to synthesize MCM-41. Then, the obtained mesoporous was modified using layered double hydroxide (MCM-41@LDH). The novel mesoporous MCM-41@LDH was successfully applied for adsorption of lysozyme (LYS) at different conditions such as adsorbent amount, pH of solution, stirrer time, and concentration of protein which were designed using central composite design (CCD). Furthermore, the chief characteristics of new adsorbent were identified using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDX) analyses. The maximum adsorption of LYS, predicted by CCD was 0.025 g of support, LYS concentration of 300 mg L-1, pH 7.50, and stirrer time of 55 min. The isotherm, kinetic, and thermodynamic equations of LYS on MCM-41@LDH were surveyed. It was established that Freundlich isotherm (R2=0.997) and second-order kinetic (R2=0.997) were the best data. Gibbs free energy (ΔG°), enthalpy (ΔH°), and entropy (ΔS°) values were obtained as -17334.5 kJ/mol K (at 298.15 K), -17346.3, and -0.04 kJ/mol, respectively. Based on the achieved results including high adsorption intensity of support (Freundlich constant, n=2.46) and the negative value of ΔG˚ (spontaneity of the adsorption process), it suggests that MCM-41@LDH should be a favorable candidate for LYS-chromatography and separation applications.
