Extraction and Crystal Structure of Karounidiol

1 INTRODUCTION Karounidiol is a natural pentacyclic triterpene compound, which was identified as a novel compound initially from the Japanese commercial seeds of Trichosanthes kirilowii Maxim. (Fam. Cucurbitaceae)[1], and then isolated from the Chinese commercial seeds of T. kirilowii Maxim. and T. rosthornii Harms[2, 3] and the Japanese wild plant seeds of T. cucumeroides (Ser.) Maxim.[4]. It has not been isolated from other plants up to now, so we are thinking about how to use th…     

Extraction and Crystal Structure of β-Sitosterol

The title compound β-sitosterol(C29H50O), an active phytosterol in many medicinal and edible plants, was characterized by X-ray diffraction analysis and extensive nuclear magnetic resonance(NMR) data. It crystallizes in monoclinic system, space group P21 with C29H50O·1/2H2O, a = 9.4226(7), b = 7.4824(9), c = 36.889(3) , V = 2597.0(4) 3, Z = 4, Dx = 1.084 g/cm3, Mr = 423.70, F(000) = 948, and μ = 0.064 mm-1. The final R = 0.0886 and wR = 0.2234 for 10157 observed reflections(I 2σ(I)). The molecular crystal structure of β-sitosterol shows relative stereochemistry of 24R-ethylcholest-5-en-3β-ol. The molecule is composed of one steroid nucleus(3 six-membered rings and 1 five-membered ring) and one sidechain of 10 carbons. There are two C29H50O molecules and one H2O molecule in a symmetrical unit, and the title compound is stacked into a special laminated structure through hydrogen bonds and van der Waal forces. The special laminated structure was first reported.     

Liquid-liquid Extraction System Based on Non-ionic Surfactant-salt-H_2O and Mechanism of Drug Extraction

The utilization of solid-liquid extraction system based on polymer-(NH4)2SO4 -H2O on separation of metal ions and bio-active substances has been summarized1. Cloud point extraction (CPE) benefits the environment and has been used in separation of metal chelates, biomacromolecules and in pretreatment of environmental samples2-4. In a 10 mL color comparison tube 20% PEG-1000 and 2.5 g (NH4)2SO4 were chosen as phase separation condition at pH 5.5. The average extraction efficiencies we…     

Extraction and Purification of Depigmenting Agents from Chinese Plants

Introduction Melaninisaheterogeneousbiopolymerproduced bytheskincells,melanocytes,whichdetermine,mostly,thecoloroftheskin.Excessiveproductionof melaninanditsaccumulationintheskincancausepig mentingdisordersincludingmelasma,solarlentigoand postinflammatory…     

Determination of Aflatoxins in Rice and Maize by Ultra-High Performance Liquid Chromatography–Tandem Mass Spectrometry with Accelerated Solvent Extraction and Solid-Phase Extraction

A fast and reliable ultra-high performance liquid chromatography–tandem mass spectrometry method was developed for the determination of aflatoxins B₁, B₂, G₁, and G₂ in cereal. The analytes were extracted by accelerated solvent extraction with methanol/water (80:20). A polymeric solid-phase extraction column was used for sample preparation. Under optimum conditions, the analyte recoveries for samples spiked at different concentration levels in rice and maize ranged from 71.2 to 94.0%, with relative standard deviations less than 16.4%. Limits of detection (signal-to-noise ratio, 3:1) for the aflatoxins ranged from 0.25 to 0.93 ng/g. The developed method was applied to the determination of aflatoxins in ten rice and maize samples. One maize sample tested positive with an aflatoxin B₁ concentration of 2.7 ng/g.     

Reverse Homogeneous Liquid–Liquid Extraction as a Miniaturized Method for Extraction of Aflatoxins from Pistachio and Wheat and LC Post-column Derivatization-Fluorescence Detection

A rapid and simple quantitative method for the simultaneous determination of the four aflatoxins (AFs) B1, B2, G1 and G2 was developed using reverse homogeneous liquid–liquid extraction (RHLEE) and HPLC post-column derivatization-fluorescence (HPLC-FL) detection. The method based on the rapid extraction of AFs from a methanolic sample into chloroform after addition of water containing KBr, with a method we called reverse homogeneous liquid–liquid extraction. Recoveries were in the range of 88–125% and the limits of detection were between 0.001–0.042 ng g^?1 for different AFs. Wheat and pistachio were chosen for the analysis of real samples and the method was also successfully applied to a FAPAS^® TEST MATERIAL (T04151).     

Lead Extraction from Natural Waters—A Simple and Rapid Technique

Abstract

A technique is described for the concentration of lead from fresh and saline waters before analysis by atomic absorption spectrophotometry. The lead is adsorbed on managanese dioxide supported on glass fibre filters. Quantitative adsorption of up to 75 mg Pb/g MnO₂ was achieved, with a maximum adsorption of 190 mg Pb g^?1. The technique, which allows rapid processing of large samples, is suited to field use.     

Extraction and determination of the potato glycoalkaloid α -solanine in soil

The toxic glycoalkaloids α-solanine and α-chaconine are produced in all parts of the potato plant, and post-harvest potato tubers may represent a source of soil and water contamination. A new method was developed for extraction and purification of α-solanine in soil samples. Soil samples were extracted with THF?:?H₂O?:?ACN?:?CH₃COOH (50?:?30?:?20?:?1) and the extract purified by SPE before HPLC determination of α-solanine. The limit of detection was 2.4?mg of α-solanine?kg^?1 soil. The new procedure was used for determination of α-solanine in spiked soils with varying content of organic matter and texture. Recovery for soil samples spiked with α-solanine 1?h before extraction was 61–68% for soils low in organic carbon (<2.2% C), and to 47% for soil high in organic carbon. Similar recoveries were obtained for α-chaconine. The reproducibility of the method shown by the relative standard deviation varied from 1.7 to 10.1%, depending on the soil type. No decrease in extractable α-solanine was observed until day 17 for soil samples spiked with pure α-solanine kept at 5°C, while the content in samples spiked with potato materials showed a faster decline. This indicates that the degradation and/or ageing processes proceed relatively slowly for glycoalkaloids in soil matrices. This is the first method reported for determination of potato glycoalkaloids in soil.     

Flow-Injection Extraction–Photometric Trace Determination of Phosphate and Silicate Ions

As an extension of the method for extraction preconcentration in flow analysis including the extraction–chromatographic recovery of analytes and the chromatomembrane separation of the extract from the aqueous phase that was proposed previously, a procedure was developed for the flow-injection extraction–photometric trace determination of phosphate and silicate ions with the use of a 1% solution of tri-n-octylamine in chloroform as the extractant. Detection limits are 5 g/L for phosphate ions and 20 g/L for silicate ions.     

Thermodynamics of Solvent Extraction of Rare and Scattered Metal-Indium with Diethylhexylmonothiophosphoric Acid

IntroductionIndium has been widely used in electronic indus-try,butin nature itcoexists with other metals instead ofexisting as a single mine.Among all the methods avail-able,extraction is the most effective one for abstractingindium.However,it is challen…     

Extraction properties of β-aminophosphine oxides towards lanthanides and alkaline earth metals

The investigation of the extraction properties of a series of polyoligodentate β-aminophosphine oxides 1–8 bearing from one to six phosphine oxide groups in a molecule towards Ln(III) and alkaline earth metals ions from neutral media has revealed that, using common diluents, the extraction efficiency increases with an increase of a number of P=O functions in a ligand. The addition of ionic liquid, namely 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([bmim][NTf₂]), significantly increasing the extraction efficiency and application of IL concentration of 0.05 M (in 1,2-dichloroethane) providing the maximum recovery of metal ions with Lu/La separation factor reaching up to 91. Hexapodal tris[bis(2-diphenylphosphorylethyl)aminoethyl]amine 8 demonstrates the highest extraction under all conditions applied and the separation factor for U and Eu of this compound exceeded 10³.      

High-Yield Synthesis and Extraction of Endohedral Metallofullerenes Dy@C_(2n)

Thesynthesisandextrationofendohedralmetallofullerenesareconsideredtobeverydriportantbecausetheyarethebasicjobforfurtherinvestigationontheirphysicalandchemicalpropertiesandapplications.TheK-Hcarbon-arcevaporationmethodhasbeenaPpliedforthebulksynthesisofendohedralmetallofuIlerenesM@C,.'AwidevarietyofmetalsincludingY,Scandmostofrare-earthsLn(Ln=La,Ce,Sm,Eu,Gd,Tb,Ho)havebeensuccessfullyencapsulatedintothefullerenecages'~'.GratifyingprogressonthespectroscopiccharacteriZations,theoreticalstU…     

Liquid—liquid Extraction Synstem Based on Non—ionic Surfactant—salt—H2O and Mechanism of Drug Extraction

Extraction behavior of chlorpromazine hydrochloride (CPZ) and procaine hydrochloride (PCN) in the system described in the title was studied. Research shows that the extraction efficiency of CPZ can amount to 96% by twice extraction, while that of PCN is 77%. This system produces the distribution coefficients (KD) of 12.3 and 2.6 respectively for CPZ and PCN. Extraction mechanism is deduced according to ultraviolet and molecular fluorescence spectra variation of the drugs in the system studied.     

Determination of Chlorophenols and Alkylphenols in Water and Juice by Solid Phase Derivative Extraction and Gas Chromatography–Mass Spectrometry

A solid phase derivative extraction method using acetic anhydride was developed for the determination of chlorophenols and alkylphenols in water and fruit juice by gas chromatography–mass spectrometry (GC–MS). The quantitative extraction was performed by passing 100 mL of sample prepared in 0.1 mol L^?1 sodium hydroxide through a column packed with 500 mg of a strong anion-exchange resin at a flow rate of 0.75 mL min^?1. The retained phenols were quantitatively derivatized in the column by the introduction of 0.25 mL of acetic anhydride. The derivatized phenols were eluted with 3.0 mL of hexane and the effluent was dried under nitrogen. The final volume was diluted to fifty microliters with hexane and analyzed by GC–MS. Under the optimum conditions, preconcentration factors of 2000, limits of detection between 0.005 and 1.796 µg L^?1, and relative standard deviations of 2.1% to 6.7% were obtained. The method was successfully applied to wastewater and fruit juice and the recoveries of phenols were between 76% and 111%.     

Determination of N-Methylcarbamate Pesticides in Vegetables by Solid-phase Extraction and Pressurized Capillary Electrochromatography

Introduction Capillary electrochromatography(CEC) is a hybrid technique that couples the good selectivity of high-performance liquid chromatography(HPLC) and the high separation efficiency of capillary electrophoresis(CE).Both charged and uncharged compou…     

Preparation and Application of an Immunoaffinity Column for Direct Extraction of Morphine and its Analogs from Opium

A rapid, simple and accurate method using an immunoaffinity column (IAC) andcapillary electrophoresis (CE) for the analysis of the major alkaloids in opium is developed. TheIAC was synthesized by coupling specific morphine polyclonal antibodies to CNBr-activedSepharose 4B. The IAC showed high selectivity and obvious enrichment to morphine, codeine,dionin and thebaine. The extraction solution was analyzed by CE with J3-cyclodextrin as anadditive. Recoveries of the four alkaloids from PBS were between 93%-105% with RSD valueless than 5.0%. The result showed that this method was practical for the determination ofmorphine analogs in opium.     

Diesel-Range Organics Extraction and Determination in Environmental Samples by Gas Chromatography‒Mass Spectrometry: Headspace Solid Phase Microextraction vs. Solvent Extraction

An accurate and sensitive analytical method for the determination of diesel-range organics (DRO) is the basis to monitoring and soil remediation studies. In the present work, the determination of DRO in different water and soil samples was optimized. Solvent extraction procedures, i.e. ultrasonic assisted extraction (USAE) (for water samples) and accelerated solvent extraction (ASE) (for soil samples), and a solvent-free procedure, headspace solid phase microextraction (HS-SPME), were optimized to achieve the highest recoveries for the simultaneous determination of all DRO. One hour of USAE for water samples and ASE of soil samples at 100°C, 2000 psi and two extraction cycles lead to analytical recoveries of 70?100%. Using HS-SPME, 30 min of incubation at 90°C were sufficient to achieve analytical recoveries up to 90% for water and soil samples. HS-SPME enables higher preconcentration factors, which makes this method more appropriate for samples with trace DRO concentrations.     

Extraction of Uranium and Thorium with TBP from Fluoride — Nitric Acid Solutions

The extraction of HNO₃, thorium and uranium were studied in the presence of hydrofluoric acid. The extraction constants of both the acids are shown to be close to one another which results in their mutual displacement from the organic phase. Contrary to uranium, the extraction of thorium is much reduced as the concentration of hydrofluoric acid increases which may be explained by a stronger complexation of Th by fluoride ion in the aqueous phase.     

Extraction and determination of biologically active components of St. John’s wort and its pharmaceutical preparations

A procedure is developed for the determination of biologically active substances (BAS) of common St. John’s wort (Hypericum perforatum L.) by HPLC using two columns, Luna C18, 100 Å (for the determination of phenolcarboxylic acids and flavonoids), and Onyx Monolithic C18 (for the determination of phloroglucinols and naphthodianthrones), in the gradient elution mode with diode array detection. The detection limits for analytes are 0.05–0.20 μg/mL. To optimize the conditions, we studied the extraction of biologically active substances from St. John’s wort by a water–ethanol solution at different temperatures and pressures and under the effect of microwave radiation and ultrasound. The maximum amounts of substances were extracted in a dynamic mode under heat and pressure. The procedure was applied to the St. John’s wort samples of different brands and some pharmaceutical products based on it. The components of extracts were identified by retention times, UV spectra, and mass spectra. It was shown that the content of biologically active substances in pharmaceutical samples of St. John’s wort depends on the herb habitat. It was shown that hyperforin decomposed in pharmaceutical formulations based on St. John’s wort during storage.     

Extraction and Determination of β-Sitosterol from Salicornia herbacea L. Using Monolithic Cartridge

A short ionic liquids-based monolithic cartridge was prepared and used as the selective extraction sorbent. Characteristic and evaluation are investigated by field emission scanning electron microscopy (FE-SEM), and a new approach was developed for the extraction and determination of β-sitosterol from Salicornia herbacea L. using the ionic liquids-based monolithic cartridge. Chromatographic analysis was conducted on a C₁₈ column with UV detection at 210 nm, and an eluting solution consisting of acetonitrile–water (60/40, v/v) was used as the mobile phase at a flow rate of 0.8 mL min^?1. The linearity was confirmed in the concentration range of 0.50–100.00 μg mL^?1, with RSDs within 4.20%, and a recovery of β-sitosterol ranging from 97.20 to 102.93%. This method effectively removed the impurities without any tedious pretreatment, and it provided a fast, economic and effective way to assay trace drugs from natural plants.