Separation of Scandium and Rare Earths with the Method of PSO-Extraction Chromatography

Separation of scandium and rare earths was investigated by using a new extraction chromatography which PSO was used as a stationary phase,while HCl-NH_4SCN solution as a mobile phase.The separation conditions were studied.In this system, the separation factor(β_(Nd)^(Sc))can reach up to 1.3×10~4.The method can be applied to the purposes of separation,purification and analysis of microquantity of Sc in the mixed rare earth.

Study on the Separation of Rare Earths with the Method of H(DEHP)-Extraction Chromatography

Separation of rare earths was investigated by extraction chromatography where H(DEHP)was used as a stationary phase,while HCl and H_2SO_4 solutions as a mobile phase.The average separation fac- tors of rare earths,β_(HCl) and β_(H_2SO_4),are 3.79 and 4.57.respectively.The β_(La)^(Ce) in HCl and H_2SO_4 systems are as high as 28.5 and 26.3,respectively.The elution acidity in the study can be down to one tenth and one four- teenth of that in HEH(EHP)system.

Separation of strontium from associated elements with selective specific resin and extraction chromatography

In this paper, separation of Sr from associated elements （Na, K, Ca, Mg, and Ba） was carried out using an extraction chromatographic column packed with Sr selective specific resin consisting of an octanol solution of 4,4＇（5＇）-bis（t-butylcyclohexo）-lS-crown-6 sorbed on an inert polymeric support. Using 8.0 mol/L HNO3 as the eluent, Ba and associated elements were eluted immediately from the column, whereas Sr was strongly retained. The adsorbed Sr could then be stripped from the column as the eluent was changed to 0.05 mol/L HNO~. Complete Sr/Ba separation was demonstrated to be feasible in that Ba could be washed from the column leaving pure Sr by adequate rinsing with 8.0 mol/L HN03. Furthermore, matrix effect could be effectively eliminated and the selectivity of the method was improved. The method was applied for the determination of Sr in the high purity barium carbonate （BaCO3） product and seawater. The recoveries of Sr in 2 samples were determined to be 93.2% and 109%, respectively.

STUDY ON THE SEPARATION AND EXTRACTION MECHANISM OF RARE EARTH ELEMENTS BY MEANS OF REVERSED-PHASE PAPER CHROMATOGRAPHY

Reversed-phase paper chromatography technique is used for study on the extraction mechanism and sep- aration of rare earth elements.As the stationary phase,chromatographic paper strips are impregnated with a solution of monomyristyl phosphoric acid (MPA) in chloroform.Mineral acids are used as developers. The effect of concentration of acids and/or salts upon R_f has been investigated.According to the re- sults of R_f values for a given rare earth element in various acids,the order of extraction ability is HCl>HNO_3>H_2SO_4.A tetrad effect is clearly observed.for the R_f value of rare earth elements.The effects of other parameters on the R_f value,such as the quantities of extractant retained by the paper and the temperature are also examined.Based on the determination of the molar ratio of MPA to rare earth elements and the number of H^+ ions released in extraction reaction,a reasonable mechanism is proposed.The mutual separation of heavy rare earth elements will be better than that of the light rare earth group because of the larger separation coefficient of the former.A mixture of Ho-Er-Tm-Lu is successfully separated by the present method.

Liquid chromatography tandem mass spectrometry method for the estimation of lamotrigine in human plasma:Application to a pharmacokinetic study

A reliable,selective and sensitive liquid chromatography tandem mass spectrometry method was developed and validated for the quantification of lamotrigine in human plasma using lamotrigine13C3,d3 as an internal standard.Analyte and internal standard were extracted from human plasma by solid-phase extraction and detected in positive ion mode by tandem mass spectrometry with electrospray ionization（ESI） interface.Chromatographic separation was performed on a Chromolith s SpeedROD;RP-18e column（50-4.6 mm i.d.） using acetonitrile：570.1 mM ammonium formate solution（90：10,v/v） as the mobile phase at a flow rate of 0.500 mL/min.The calibration curves were linear over the range of 5.02-1226.47 ng/mL with the lower limit of quantitation validated at 5.02 ng/mL.The analytes were found stable in human plasma through three freeze（-20℃）-thaw（ice-cold water bath） cycles and under storage on bench-top in ice-cold water bath for at least 6.8 h,and also in the mobile phase at 10℃ for at least 57h.The method has shown good reproducibility,as the intra-and inter-day precisions were within 3.0%,while the accuracies were within 76.0% of nominal values.The validated LC-MS/MS method was applied for the evaluation of pharmacokinetic and bioequivalence parameters of lamotrigine after an oral administration of 50mg lamotrigine tablet to thirty-two healthy adult male volunteers.

Optimization of Ultrasonic Extraction and Clean-up Protocol for the Determination of Polycyclic Aromatic Hydrocarbons in Marine Sediments by High-performance Liquid Chroma-tography Coupled with Fluorescence Detection

The procedures of ultrasonic extraction and clean-up were optimized for the determination of polycyclic aromatic hydrocarbons (PAHs) in marine sediments. Samples were ultrasonically extracted, and the extracts were purified with a miniaturized silica gel chromatographic column and analyzed with high performance liquid chromatography (HPLC) with a fluorescence detector. Ultrasonication with methanol-dichloromethane (2:1, v/v) mixture gave higher extraction efficiency than that with dichloromethane. Among the three elution solvents used in clean-up step, dichloromethane-hexane (2:3, v/v) mixture was the most satisfactory. Under the optimized conditions, the recoveries in the range of 54.82% to 94.70% with RSDs of 3.02% to 23.22% for a spiked blank, and in the range of 61.20% to 127.08% with RSDs of 7.61% to 26.93% for a spiked matrix, were obtained for the 15 PAHs studied, while the recoveries for a NIST standard reference SRM 1941b were in the range of 50.79% to 83.78% with RSDs of 5.24% to 21.38%. The detection limits were between 0.75 ng L-1 and 10.99 ng L-1for different PAHs. A sample from the Jiaozhou Bay area was examined to test the established methods.

磷酸三丁酯负载聚氨酯泡塑萃取色层分离分光光度法测定微量铀

用2—(5—溴—2—吡啶偶氮)—5—二乙氨基苯酚(简称5—Br—PADAP)分光光度法测定铀有较高的灵敏度和选择性。但是,在样品中含铀量低,共存元素种类多,称样量大时,杂质干扰大,必须经过分离后才能测定。萃取色层分离是用于此目的的一种有效方法。有人介绍用硅球为支持体,磷酸三丁酯(TBP)为固定相,硝酸—硝酸铵溶液为移动相的萃取色层法使铀与共存元素分离,然后用5—Br—PADAP法测定。用作支持体的硅球,需先经硅烷化处理,手续繁琐。近年来,聚氨酯泡沫塑料(以下简称泡塑)

利用N-正辛基苯胺萃取色谱法从含铝(Ⅲ)混合物中分离铝(Ⅲ)(英文)

A selective method has been developed for the extraction chromatography of aluminium(Ⅲ) and its separation from several metal ions with a chromatographic column containing N-n-octylaniline ( a liquid anion exchanger) coated on silanized silica gel as a stationary phase. The aluminium(Ⅲ) was quantitatively extracted with the 0. 065 mol / L N-n-octylaniline in 0. 013 to 0. 05 mol / L sodium succinate at a flow rate of 1. 0 mL / min. The extracted metal ion has been recovered by eluting with 25. 0 mL of 0. 05 mol / L hydrochloric acid and estimated spectrophotometrically with aurintricarboxylic acid. The effects of the acid concentration,the reagent concentration,the flow rate and the eluting agents have been investigated. The log-log plots of distribution coefficient ( K d ( Al(Ⅲ) ) ) versus N-n-octylaniline concentration in 0. 005 and 0. 007 mol / L sodium succinate gave the slopes of 0. 5 and 0. 7 respectively and showed the probable composition of the extracted species was 1∶ 1 ( metal to amine ratio ) and the nature of extracted species was [RR' NH + 2 Al succinate 2 ] org. . The extraction of aluminium(Ⅲ) was carried out in the presence of various ions to ascertain the tolerance limit of individual ions. Aluminium(Ⅲ) has been separated from multicomponent mixtures,pharmaceutical samples and synthetic mixtures corresponding to alloys. A scheme for mutual separation of aluminium(Ⅲ) ,indium(Ⅲ) ,gallium(Ⅲ) and thallium(Ⅲ) has been developed by using suitable masking agents. The method is fast,accurate and precise.

Recent Advances in Separation of Bioactive Natural Products

Bioactive natural products are a main source of new drugs,functional foods and food additives.The separation of bioactive natural products plays an important role in transformation and use of biomass.The isolation and purification of bioactive principle from a complex matrix is often inherent bottleneck for the utilization of natural products,so a series of extraction and separation techniques have been developed.This review covers recent advances in the separation of bioactive natural products with an emphasis on their solubility and diffusion coefficients,recent extraction techniques and isolation techniques.This overview of recent technological advances,discussion of pertinent problems and prospect of current methodologies in the separation of bioactive natural products may provide a driving force for development of novel separation techniques.

Determination of berberine in Phellodendron amurense from different sites of Changbai Mountain

Phellodendron amurense has been used for many years as a medical plant in traditional Chinese medicine and has shown great prospect in recent clinical trials for future applications. Berberine is an essential active compound contained in P. amurense. Our objective in this study was to quantify the content of berberine in P.amurense from sites at different elevations on Changbai Mountain. We collected samples of P. amurense from five different elevations on Changbai Mountain. Berberine in samples was extracted by ultrahigh pressure extraction（UPE）. And the quantity was measured by high performance liquid chromatography（HPLC）. First, the optimal HPLC conditions for berberine were identified with satisfactory precision（relative standard deviation, R SD／5.6 %）, good accuracy（relative error, R E／ 3.6 %） and good linear relation（R2= 0.9998） in the range of 6.576–328.8 mg L-1. Second, the combination of UPE and HPLC methods in quantitative analysis of berberine showed high repeatability（R SD= 3.28 %）, reproducibility（R SD= 4.72 %）,stability（R SD／ 1.27 %） and good recovery（99.54 %） for real plant materials. Samples from Heilongjiang Province at the lowest elevation contained the highest amount of berberine.Similarly, the lowest amount of berberine was recorded in samples from Changbai Forest Bureau of Jilin Province collected at the highest elevation in this paper. The proposed UPE–HPLC method is simple, reliable and low-cost for quantitative analysis of berberine. Content of berberine in P.amurense varied significantly by site on Changbai Mountain.

Analysis of trace dicyandiamide in stream water using solid phase extraction and liquid chromatography UV spectrometry

An improved method for trace level quantification of dicyandiamide in stream water has been developed. This method includes sample pretreatment using solid phase extraction.The extraction procedure（including loading, washing, and eluting） used a flow rate of1.0 m L/min, and dicyandiamide was eluted with 20 m L of a methanol/acetonitrile mixture（V/V = 2：3）, followed by pre-concentration using nitrogen evaporation and analysis with high performance liquid chromatography–ultraviolet spectroscopy（HPLC–UV）. Sample extraction was carried out using a Waters Sep-Pak AC-2 Cartridge（with activated carbon）.Separation was achieved on a ZIC-Hydrophilic Interaction Liquid Chromatography（ZIC-HILIC）（50 mm × 2.1 mm, 3.5 μm） chromatography column and quantification was accomplished based on UV absorbance. A reliable linear relationship was obtained for the calibration curve using standard solutions（R^2〉 0.999）. Recoveries for dicyandiamide ranged from 84.6% to 96.8%, and the relative standard deviations（RSDs, n = 3） were below 6.1% with a detection limit of 5.0 ng/m L for stream water samples.

Assessment of malathion and its effects on leukocytes in human blood samples

In the present paper,we report a reproducible,cost effective,fast response method for detection of malathion and its effects on leukocytes in different human blood groups.Spectroscopic methods（UV-Vis spectrometry）and Fourier transform infrared coupled with solid phase extraction were applied for analyzing malathion content in human blood plasma.The spiking levels of malathion in the range of 0.1-1.7μg/mL were extracted from blood plasma samples using SPE.The present active functional groups（C=0;P-O-C;-OH;P=S）were also characterized.The recovery rate of malathion was 80%±4.5%.The calculated correlation coefficient was 0.9799,indicating the linearity of the results.The limit of detection（LOD）and limit of quantification（LOQ）were（0.1-1.7）μg/mL and（0.3-1.5）μg/mL,respectively.Malathion〈1.0μg/mL showed no significant change while higher levels of malathion exposure（1.5μg/mL and 3.0｜ig/mL）reduced the number of white blood cells.In conclusion,the spectroscopic results may be useful to understand the mechanism of other pesticides such as methyl parathion and parathion.

Metal-organic framework derived magnetic nanoporous carbon as an adsorbent for the magnetic solid-phase extraction of chlorophenols from mushroom sample

In this work, a metal-organic framework derived nanoporous carbon （MOF-5-C） was fabricated and modified with Fe3O4 magnetic nanoparticles. The resulting magnetic MOF-5-derived porous carbon （Fe304@MOF-5-C） was then used for the magnetic solid-phase extraction of chlorophenols （CPs） from mushroom samples prior to high performance liquid chromatography-ultraviolet detection. Scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and N2 adsorption were used to characterize the adsorbent. After experimental optimization, the amount of the adsorbent was chosen as 8.0 mg, extraction time as 10 min, sample volume as 50 mL, desorption solvent as 0.4 mL （0.2 mL × 2） of alkaline methanol, and sample pH as 6. Under the above optimized conditions, good linearity for the analytes was obtained in the range of 0.8-100.0 ng g 1 with the correlation coefficients between 0.9923 and 0.9963. The limits of detection （SIN= 3） were in the range of 0.25-0.30 ng g-1, and the relative standard deviations were below 6.8%. The result showed that the Fe304@MOF-5-C has an excellent adsorption capacity for the analytes.

An advanced partitioning process for key elements separation from high level liquid waste

To separate MA （Am, Cm） and some fission product elements （FPs） such as Tc, Pd, Cs and Sr from high level liquid waste （HLLW） systematically, we have been studying an advanced aqueous partitioning process, which uses selective adsorption as the separation method. For this process, we prepared several novel adsorbents which were immobilized in a porous sili- c^polymer composite support （SiO2-P）. Adsorption and separation behavior of various elements was studied experimentally in detail. Small scale separation tests using simulated HLLW solutions were carried out. Pd（II） was strongly adsorbed by the AR-01 anion exchanger and effectively eluted off by using thiourea. Successful separation of Pd（ll） from simulated HLLW was achieved. Te（VII） also exhibited strong adsorption on AR-01 and could be eluted off by using U（IV） as a reductive eluent. Am（Ⅲ） presented significantly high adsorbability and selectivity onto R-BTP/SiOz-P adsorbents over various FPs including Ln（Ⅲ）. The R-BTP adsorbents were fairly stable in 3 M HNO3, but instable against 7-irradiation-3M HNO3. An advanced par- titioning process consisting of three separation columns for the target elements separation from HLLW was proposed and the obtained experiment results indicated that the proposed process is essentially feasible.

Study on the diffusion kinetics of adsorption of heavy rare earth with Cyanex272-P507 impregnated resin

Kinetics of adsorption of heavy rare earth with Cyanex272-P507 impregn ated resin was studied. The influences of temperature,concentration,granularit y of resin on the exchange degree were investigated by the limited bath method. The result showed that the controlling factor of RE3+/H+ diffusion on Cyanex272-P507 extraction resin was particles diffusion. The process of diffuse kinetics f itted well with the expression developed by Body model. The apparent activation energy was determined as 23.20 kJ/mol. The reaction order was 0.452. In addition,the constant of particles diffusion(D0) was 1.352×10-8 m2/S and the entropy of diffusion was-47.055 J/(mol·K).