固相萃取光度法测定环境水样中汞的研究

研究了用固相萃取光度法测定环境水样中汞,在pH 9.0～10.0的硼砂-氢氧化钠缓冲体系中,非离子表面活性剂--乳化剂OP存在下,硝基苯并噻唑重氮氨基偶氮苯(NBT-DAA)与汞反应形成2:1的络合物,该络合物可用C18固相萃取小柱萃取富集,小柱上富集的络合物用N,N-二甲基甲酰胺(DMF)洗脱.在DMF介质中络合物最大吸收波长为515 nm,表观摩尔吸光系数为1.38×105,汞含量在0～1.0 μg/mL范围内符合比尔定律.用于环境水样中汞的测定,相对标准偏差为1.8%～2.4%,回收率为94%～106%.

老化P_(507)萃取剂再生研究

研究了用试剂R12 再生老化P50 7萃取剂工艺 ,讨论了R12 用量、反应时间对再生P50 7萃取剂可见光谱、萃取稀土分相时间、P50 7收率的影响。本方法在生产实践中业已取得成功。实验和应用结果表明 ,再生P50 7萃取剂与新配制P50 7萃取剂在萃取分离稀土性能上无明显差异和变化。本方法简单易行、成本低廉。

Study on the Chromatographic Fingerprint of Volatile Constituents from Acacia Honey

[Objective] The experiment aimed to study chromatographic fingerprint in volatile components of acacia honey and provide scientific evaluation and effective control on quality of acacia honey.[Method] Using solid-phase microextraction method to separate and detect volatile components and construct chromatographic fingerprint.[Result] The honey was preheated for 15 min in water bath at 40 ℃ and solid-phase microextraction 85 μmPA was used to extract in overhead air about 30 min,then put it into the injector and desorpted 3 min,which is in 230 ℃.The Supelco WaxTM10 30 m×0.25 mm×0.25 μm column and gradient heating program was the best method to separate volatile components from honey.83 fingerprint peaks were constructed,among which 17 common fingerprint peaks were comprised of chromatographic fingerprint of volatile components of acacia honey.[Conclusion] The chromatographic fingerprint could provide reference for quality control of acacia honey.

Phase separation in solvent extraction of cobalt from acidic sulfate solution using synergistic mixture containing dinonylnaphthalene sulfonic acid and 2-ethylhexyl 4-pyridinecarboxylate ester

Phase separation rate is a critical character in determining the usefulness of a solvent extraction system in hydrometallurgy. A survey of the synergistic mixture containing dinonylnaphthalene sulfonic acid (HDNNS) and 2-ethylhexly 4-pyridinecarboxylate ester (4PC) for the extraction of cobalt from acidic single metal sulfate solution was carried out to suggest how the physicochemical properties and the morphology of the reverse micelles in the loaded organic phase affect the phase separation. The results show that effective parameters affecting the phase separation are the viscosity and the excess water uptake of the loaded organic phase. It is obvious that the specific settling rate (SSR) decreases with the apparent increase of these two parameters. The measurement of small angle X-ray scattering (SAXS) proves that the morphology of the reversed micelles in the loaded organic phase changes evidently with the change of the specific settling rate (SSR).

Separation of Quercentin by Pre-dispersed Solvent Extraction

Pre-dispersed solvent extraction (PDSE) was used to extract quercentin from its diluted solution. The influences of temperature, phase volume ratio (PVR), concentration of sodium Dodecyl benzene sulphonate and pH value etc. on the extraction efficiency were examined. It is found that, compared with traditional extraction techniques under the same condition, a higher extraction productivity can be obtained by PDSE. The stability of colloidal liquid aphrons plays an important role in this process. In a certain scope, the extraction efficiency increases with PVR. Excessive amount of solvent is not much helpful. A new analytical method by using ultraviolet spectrometer to determine the concentration of quercentin is established.

用蒸馏水替代血浆溶解亚甲蓝进行质控的方法可行性探讨

目的按照《血站技术操作规程(2012版)》(以下简称《规程》)附录F.19方法对我站病毒灭活血浆亚甲蓝含量项目进行检测方法验证和用蒸馏水替代血浆溶解亚甲蓝进行质控的方法可行性探讨。方法分别检测含有已知浓度亚甲蓝的标准质控血浆固相萃取后比色、含有已知浓度亚甲蓝的水溶液固相萃取后同法比色和含有已知浓度亚甲蓝1%乙酸甲醇溶液同法直接比色,三组数据相比较,检验固相萃取操作对亚甲蓝萃取程度影响。结果与含有已知浓度亚甲蓝的1%乙酸甲醇溶液直接比色相比,含有等量亚甲蓝水溶液和含有同浓度亚甲蓝的血浆经过Waters Oasis HLB小柱固相萃取到1%乙酸甲醇溶液中,再用分光光度计比色结果相比,亚甲蓝萃取率回收率在92.9%以上,且线性度好。结论 1)固相萃取分光光度计法检测亚甲蓝方法具有良好亚甲蓝回收率和可重复性,作为病毒灭活血浆中亚甲蓝含量常规质控方法是有效可行的。2)同样浓度的亚甲蓝蒸馏水介质和在血浆介质中固相萃取后检测得到亚甲蓝含量值基本一致,表明在血浆缺乏时,可用蒸馏水或1%乙酸甲醇代替血浆做亚甲蓝释放含量检测。

Simultaneous Cell Disruption and Aqueous Two-Phase Extraction for Isolation of Intracellular Recombinant Proteins

A new technique was developed for the integrated processing of cell disruption and aqueous two-phase extraction in a high-speed bead mill to separate intracellular proteins from microbial cells. The process was named as simultaneous cell disruption and aqueous two-phase extraction (SDATE). Advantages, such as high cell disruption efficiency, biochemical activities preservation of proteins, cell debris elimination, and prelimiary purification of the target protein were being claimed. When this technique was employed for isolating recombinant Tumor Necrosis Factor (TNF) from E. coli, overall protein concentration and TNF activity were found to have been increased. More than 95% of TNF was partitioned into the top phase and all cell debris were in the bottom phase. The partition coefficient was greater than 3 and the TNF purification factor was greater than 6. It is shown that less separation steps were being utilized in the new technique, meaning a reduction in separation time and less process extractors required.

Isolation and Sorption Behavior of Humic Acid from Zhongdian Peat of Yunnan Province,China

The Zhongdian swamp meadow in Zhongdian,China is well known as "Shangri-la",where the peat has never been studied for its potential to interact with pollutants.Humic acid(HA) was extracted from Zhongdian peat using two methods,namely sodium pyrophosphate extraction(SPE) and dilute base extraction(DBE),and characterized for its functional groups and sorption property.The HAs extracted by both methods contained several active functional groups and had large external specific surface areas.The adsorption mechanism of methylene blue onto HAs was interpreted as Langmuir sorption.SPE-HA showed higher sorption capacity because of its larger specific surface area,whereas the extraction yield of DBE-HA was twice that of SPE-HA.Kinetics modeling indicated that the sorption of methylene blue was a two-component first order reaction.The component with the higher rate constant also showed higher sorption capacity.No pH effect was observed for methylene blue sorption on HA in our experimental design,and the sorption decreased as the temperature increased.

Prediction of dispersed phase holdup in pulsed disc and doughnut solvent extraction columns under different mass transfer conditions

Using experimental data from a number of pulsed disc and doughnut solvent extraction columns, a unified correla- tion for the prediction of dispersed phase holdup that considers the effects of mass transfer is presented. Pulsed disc and doughnut solvent extraction columns （PDDC） have been used for a range of important applications such as ura- nium extraction and nuclear fuel recycling. Although the dispersed phase holdup in a PDDC has been presented by some researchers, there is still the need to develop a robust correlation that can predict the experimental dispersed phase holdup over a range of operating conditions including the effects of mass transfer direction. In this study, dis- persed phase holdup data from different literature sources for a PDDC were used to refit constants for the correlation presented by Kumar and Hartland lind. Eng. Chem. Res.,27 （1988）,131-138] which did not consider the effect of col- umn geometry. In order to incorporate the characteristic length of the PDDC （i.e. the plate spacing）, the unified cor- relation for holdup proposed by Kumar and Hartland based on data from eight different types of columns [Ind. Eng. Chem. Res.,34 （1995） 3925-3940] was refitted to the PDDC data. New constants have been presented for each hold- up correlation for a PDDC based on regression analysis using published holdup data from PDDCs that cover a range of onerating conditions and nhwical nronerties and consider the direction of mass transfer.

Comparison of the Reynolds-averaged Turbulence Models on Single Phase Flow Simulation in Agitated Extraction Columns

The flow field of liquid phase (water) of agitated extraction columns is simulated with the help of computational fluid dynamics (CFD). Four kinds of Reynolds-averaged turbulence models, i.e. the standard k-ε model, the RNG (renormalization group) k-s model, the realizable k-ε model and the Reynolds stress model, are compared in detail in order to judge which is the best model in terms of the accuracy, less CPU time and memory required. The performance of the realizable k-s model is obviously improved by reducing the model constant from C2 = 1.90 to C2 = 1.61. It is concluded that the improved realizable k-e model is the optimal model.

Detection of Tetracycline Antibiotics in Water by Dispersive Micro-solid Phase Extraction using Fe_(3)O_(4)@[Cu_(3)(btc)_(2)]Magnetic Composite Combined with Liquid Chromatography-Tandem Mass Spectrometry

Residues of tetracycline antibiotics(TCs) in environments may be harmful to human.Due to their high polarities,it is extremely challenging to efficiently enrich TCs with low concentrations in natural waters for analysis.In this work,a magnetic metal-organic framework Fe_(3)O_(4)@[Cu_(3)(btc)_(2)]was synthesized and applied as a dispersive micro-solid phase extraction adsorbent for TCs enrichment.Effects of dispersive micro-solid phase extraction conditions including extraction time,solution p H,and elution solvent on the extraction efficiencies of TCs were investigated.Results show that TCs could be enriched efficiently by Fe_(3)O_(4)@[Cu_(3)(btc)_(2)],and electrostatic interaction between TCs and Fe_(3)O_(4)@[Cu_(3)(btc)_(2)]dominated this process.Combined with liquid chromatography-tandem mass spectrometry,four TCs residues (oxytetracycline,tetracycline,chlortetracycline,and doxycycline) in natural waters were determined.The detection limits (LOD,S/N=3) of the four antibiotics were 0.01-0.02μg/L,and the limits of quantitation (LOQ,S/N=10)were 0.04-0.07μg/L.The recoveries obtained from river water and aquaculture water spiked with three TCs concentration levels ranged from 70.3%to 96.5%with relative standard deviations of 3.8%-12.8%.Results indicate that the magnetic metal-organic framework based dispersive micro-solid phase extraction is simple,rapid and high-loading for antibiotics enrichment from water,which further expand the practical application of metal-organic frameworks in sample pretreatment for environmental pollutant analysis.

Measurement of Mass Transfer Coefficients and Their Modelling of Continuous Counter-Current Aqueous Two-Phase System in a Packed Extraction Column

Overall dispersed side volumetric mass transfer coefficients for protein and amino acids were measured in continuous countercurrent PEG4000/KHP aqueous two-phase systems in a 57mm I.D. packed extraction column. A model for overall dispersed side volumetric mass transfer coefficients was derived by describing the motion of the drops based upon Navier-Stokes equation combined with the relationship between mass transfer coefficients and the drop velocity. The model provides good predictions and can be successfully used in aqueous two-phase extraction. The average relative deviation between calculated values and experimental data ranges from 8% to 14%.

CS_2 extraction and FTIR & GC/MS analysis of a Chinese brown coal

The abundance of low-rank coals in China, such as bituminous and brown coals, makes studies of their composition and structure of great significance to both coal chemistry research and for efficient utilization of the coal. We describe how a Chinese brown coal was ultrasonically extracted with carbon disulfide （CS2） and the raw and extracted coals were characterized by Fourier Transform Infrared Spectroscopy （FTIR）. The corresponding extract was analyzed with a coupled gas chromatograph mass spectrometer （GC/MS）. The FTIR analysis shows a great abundance of amidocyanogen, carbonyl, aromatic and hetero aromatic rings and single carbon-beteroatom bonds. This suggests the possible occurrence of compounds like alcohols, phenols, amines, esters, carboxylic acids, ethers, aromatics or heteroaromatics. The GC/MS analysis of the CS2 extract detected 62 compounds, among which the non-polar ones were of lower abundance while the polar ones were in higher abundance and were structurally diverse. This demonstrates the compositional and structural complexity of Shengli coal.

Extraction and analysis of polyunsaturated fatty acid from Asterina pectinifera in Huanghai Sea

The full fats of Asterina pectinifera in Huanghai Sea were extracted and refined using solvent extraction combined with silica gel colmnn chromatography with yield of 1.64%. The full fats were analyzed by gas chromatography and the result indicated that the full fats from Asterina pectinifera contained abundant Polyunsaturated Fatty Acid （PUFA） with a total of 25 kinds, especially rich in EPA and DHA. After enrichment by silica gel colmnn chromatography, the total PUFA content in ligarine fraction is 42.20%, in which EPA and DHA account for 12.50% and 10.33% respectively. The total PUFA content in acetic ether fraction is 48.98%, in which EPA and DHA take up 17.53% and 6.59% respectively. The total amount of EPA and DHA in both fractions all exceeded that of the fish oil from deep sea. In conclusion, the Asterina pectinifera in Huanghai Sea is a favorable source of PUFA.

Determination of brominated diphenyl ethers in atmospheric particulate matter using selective pressurized liquid extraction and gas chromatography–mass spectrometry with a negative chemical ionization

This study describes the development and validation of a sensitive and reliable method for determination of polybrominated diphenyl ethers（PBDEs）in atmospheric particulate matter using selective pressurized liquid extraction（SPLE）and gas chromatography–mass spectrometry with a negative chemical ionization（GC-NCI-MS）.Extraction and clean-up were performed using PLE with 2 g florisil and 3 g silica placed in the extraction cells.Under optimal conditions,14 PBDEs were extracted at 70℃ using hexane/dichloromethane（50：50,v/v）as solvent.Validation of SPLE returned excellent recoveries for most analytes,with relative standard deviations mostly below20%.Method detection limits ranged from 0.13 to15.38 ng·mL^-1 for the GC-MS analyses.The method was successfully applied to atmospheric particulate matter of Beijing,where analytes were detected in the range of182.79 to 468.99 pg·m^-3.

High-pressure Phase Equilibria for Binary Ethanol System Containing Supercritical CO_2

High-pressure phase behavior of supercritical (SC) CO2+ethanol system was investigated at 333.2 K,348.2K, 353.2K, 368.2K, 413.2K and 453.2K and pressure from 2.0MPa to 14.3MPa. The measurement was carried out in a cylindrical autoclave with a moveable piston and a window for adjustment and observation of phase equilibria at given T and p. The samples were taken from two coexisting phases and were analyzed to obtain their compositions. It is shown that the solubility of SC CO2 in ethanol increases drastically with pressures at the given temperature, but the content of ethanol in CO2-rich phase increase faintly.

Study on Aroma Components of Six Kinds of Plum Fruits

[Objective] The aim was to study the aromas composition of plum fruit. [Method] The aroma components of six kinds of plum fruits were analyzed by SPME, detected and identified by GC-MS.[Result] 85 kinds of aroma substances were separated and identified, including 40 kinds of common components.The experiments had good reproducibility by strictly controlling the desorption temperature, time and sample holding time.The obtained chromatographic peak retention time and the normalized area variation coefficient CV% values were between 0.03% -0.54% and 5.85% -18.08% by experimenting the five precision of AoLi13.The qualitative and quantitative were fully meet repeatability requirements for test samples. [Conclusion] The study provided scientific basis for the development and process of plum industry in China.

Essential Oils Composition of Two Endemic Umbelliferae Herbs Growing Wild in Turkey

The present study was carried out to determine the essential oil composition of aerial parts of two endemic umbelliferae herbs （Malabaila lasiocarpa Boiss. and Stenotaenia macrocarpa Freyn ＆ Sint. ex Freyn） collected from Bingol （Turkey）, using headspace solid-phase microextraction method and gas chromatography （GC） interfaced with mass spectrometer analysis. Forty six and 43 compounds were identified for M. lasiocarpa and S. macrocarpa, respectively, representing 91.40% and 90.86% of their respective essential oils. Germacrene D （20.71%）,β-elemene （12.40%）, spathulenol （11.60%） and β-selinene （9.67%） were identified as the major compound of M. lasiocarpa. β-sesquiphellandrene （19.68%）, hexyl isobutyrate （12.65%） and octanal （9.53%） were found to be the major compounds ofS. macrocarpa. Essential oil composition ofM. lasiocarpa has been determined for the first time and the results have been discussed in view of chemotaxonomy, natural products and potential usefulness of these plants.

Assessment of Triazine Herbicides in Soil by Microwave-assisted Extraction Followed by Gas Chromatography Coupled to Mass Spectrometry Detection

An alternative and fast method for the analysis of a mixture of nine triazines herbicides in soil is presented. The method is based on MAE （microwave-assisted extraction） of herbicides using ethyl acetate as extractant. The economy in the use of solvents coupled with the decrease in extraction time and lower power consumption make MAE a technique that meets the principles of green chemistry. MAE operational parameters, extraction time, mass of the sample and extraction temperature, were optimized by RSM （response surface methodology）. Determination of analytes was completed using gas chromatograph coupled to mass spectrometry detection. The selected triazines could be efficiently extracted by the solvent at 80 ℃ for 10 min, with 80% output of maximum power. When the optimized method was applied to analysis samples, the recoveries of analytes ranged from 81.8 to 106.0% and relative standard deviations were lower than 8.41%. The method is stable and reasonable, which can be used for the determination of ninetriazine herbicides residues in soil.

Novel Gas-assisted Three-liquid-phase Extraction System for Simultaneous Separation and Concentration of Anthraquinones in Herbal Extract

Gas-assisted three-liquid-phase extraction(GATE), which has the advantages of both three-liquid-phase extraction and solvent sublation, is a novel separation technique for separation and concentration of two organic compounds into different phases in one step. This highly effective and economically applicable method has been developed for separating emodin and rhein from herbal extract. In a GATE system composed of butyl acetate/PEG4000/ammonium sulfate aqueous solution, influence of various parameters including gas flow rate, flotation time, salt concentration, initial volume of PEG and butyl acetate was investigated. Within 50 min of 30 ml·min-1nitrogen flow, removal ratio of emodin and rhein from aqueous phase could be over 99% and 97%, respectively.Mass fraction of emodin in the BA phase and rhein in the PEG phase could reach 97% and 95%, respectively. It is demonstrated that gas bubbling is effective for partitioning of emodin and rhein into butyl acetate and PEG phase respectively, and dispersed PEG and butyl acetate could be captured from the aqueous solution. Experimental results show that GATE could be an effective and economical technology for concentration and separation of co-existed products in medicinal plants.