Determination of quinolizidine alkaloids in traditional Chinese herbal drugs by nonaqueous capillary electrophoresis.

A rapid method for the determination of quinolizidine alkaloids by nonaqueous capillary electrophoresis was developed. A total of 10 alkaloids (matrine, sophocarpine, oxymatrine, oxysophocarpine, sophoridine, cytisine, sophoramine, aloperine, lehmannine and dauricine) could be easily separated within 18 min. A running buffer composed of 50 mM ammonium acetate, 10% tetrahydrofuran and 0.5% acetic acid in methanol was found to be the most suitable for this separation. Five of these alkaloids were selected for further studies. The linear calibration ranges were 2.51-50.1 microg/ml for sophoridine and sophocarpine, 2.71-54.2 microg/ml for matrine, 3.30-65.9 microg/ml for oxymatrine, and 3.10-62.0 microg/ml for oxysophocarpine. The recovery of the five alkaloids was 98.0-101.3% with relative standard deviations from 1.03 to 2.68% (n=5). The limits of detection for all 10 alkaloids were over the range 0.93-2.31 microg/ml. The method was successfully applied to the phytochemical analysis of alkaloid extracts from three commonly used traditional Chinese herbal drugs: Sophora flavescens Ait. (Kushen), S. alopecuroides L. (Kudouzi or Kugancao) and S. tonkinensis Gapnep (Shandougen).     

Separation of double-stranded DNA fragments in plastic capillary electrophoresis chips by using E99P69E99 as separation medium.

The separation of double-stranded DNA (dsDNA) fragments in polymethylmethacrylate (PMMA) capillary electrophoresis (CE) chips by using E99P69E99 as a separation medium has been demonstrated. The PMMA CE chips were simply manufactured by micromachining and adhesive tape sealing. To make the separation channel compatible with the separation medium, a dynamic nonionic surfactant coating procedure was developed, which made the plastic separation channel sufficiently hydrophilic to allow the separation medium to fill the channel by capillary action. Subsequent separation of DNA fragments was successful with a separation efficiency of the order of 10(4) theoretical plates over an effective separation distance of 1.5 cm. By using an applied electric field strength of 200 V/cm, the separation of low DNA mass ladder was completed within 5 min. The simple coating procedure, together with the self-assembled viscosity-adjustable separation medium, should be useful to meet some of the essential requirements for developing single-use disposable CE chips. Coating the channels with polymer blends of PMMA and the separation medium also showed promise.     

Poly(N-isopropylacrylamide)-g-poly(ethyleneoxide) for high resolution and high speed separation of DNA by capillary electrophoresis.

A new separation medium, poly(N-isopropylacrylamide)-g-poly(ethyleneoxide) (PNI-PAM-g-PEO) solution, used for double-stranded (ds) DNA separation by capillary electrophoresis (CE) is presented. This type of grafted copolymer has a good self-coating ability for quartz capillary tubing and a slightly temperature-dependent viscosity-adjustable property, making it easier to use. One bp resolution was achieved within 12.5 min by using 8% w/v PNIPAM-gPEO in 1 x TBE (Tris-borate-ethylenediaminetetraaceticacid) buffer with an effective column length of 10 cm and an applied electric field strength of 200 V/cm. The PNIPAM-g-PEO solutions had a high sieving ability for relatively small sized DNAs with the relative standard derivation for the first 10 runs being less than 0.9% by using the same polymer solution. With 8% w/v PNIPAM-g-PEO solution in a 1.5 cm column and 2400 V as the running voltage, phiX174/HaeIII digest could be clearly separated within 24 s.     

Identification of137Cs in an individual microparticle by laser desorption/ionization ion trap mass spectrometer

The detection of radiocesium in microparticles was performed by using an ion trap mass spectrometer coupled with laser desorption and ionization. Pulsed laser desorbed particle and the resulted ions were analyzed by an ion trap mass analyzer. The presence of radiocesium, especially about¹³⁷Cs, in microparticles was verified by single as well as successive particle analysis. The detection limit was reached to ≈ag/particle level with a signal-to-background ratio of 4. The inhomogeneous distribution of particle size and the irregular shapes of particle limit the quantitative evaluation of¹³⁷Cs concentration in the microparticle. But this high sensitivity allows to monitor directly the radiocesium from small amounts of a microparticle sample.     

Analysis of Chlorogenic Acid in Herbal Medicines by Capillary Electrophoresis

Atpresent,thecommonlyusedmethodforanalyzingherbalmedicinesishighperformanceliquidchromatography(HPLC).However,theuseofHPLCisrestrictedformanyreasons.Themostseriousproblemisthatthechromatographiccolumniseasilycontaminated.ComparedwithHPLC,capillaryelectrophoresis(CE)ischaracterizedwithhighefficiency,rapidity,lowcostandmultiplemodestobechosen.Inaddition,thecapillarycanbeeasilyregenerated.SoCEisidealforanalyzing"dirty"samples,suchasChineseherbalmedicines.Infact,studiesintheareaarebecoming…     

7-(1-苯偶氮)-8-羟基喹啉-5-磺酸显色双波长吸光光度法测定硫化锌基颜料中微量铟的研究

研究了7-(1-苯偶氮)-8-羟基喹啉-5-磺酸与铟的显色反应及分析应用,在曲拉通X-100存在下,于pH4.5的NaOAc-HOAc缓冲介质中,铟与显色剂形成组成比为1:3的黄色配合物,最大吸收波长为440nm,表观摩尔吸光系数为3.86×10~4,同时在550nm呈现负峰,用双峰双波长法测定铟,ε=7.33×10~4,线性范围为0～0.6mg·L~(-1),方法用于硫化锌基颜料中铟的测定,结果满意.     

用离子抑制色谱法分析二（2,2,6,6—四甲基—4—哌啶基）马来酸酯合？…

建立了用离子抑制色谱法分析二（２,２,６,６－四甲基－４－哌啶基）马来酸酯合成反应液的方法。平均回收率为９８．８％,相对标准偏差为０．５６％,测量的平均相对偏差不大于５．０％,方法简单,快速,可用于工艺条件的选择和质量检测。     

小蘖碱与核酸作用荧光光谱及其分析应用

报道了小蘖碱与核酸（ＤＮＡ）作用的荧光光谱。在ＰＨ值３．０－９．１范围内小蘖碱与ＤＮＡ作用。荧光谱发生了显著变化,λｃｍ－５３１ｎｍ的荧光峰随着ＤＮＡ的浓度增加,荧光强度显著增强,据此奶可达１．１μｇ／Ｌ。确定了最佳条件,方法简便快速,对合成样品中ＤＮＡ测定结果令人满意。     

Synthesis of Lanthanide–Alkylaluminium Bimetallic Complexes and Studies on Their Catalytic Activities for Polymerization of Some Polar Monomers

Three new lanthanide (Ln)–alkylaluminium (Al) bimetallic complexes with the formula [(μ-CF₃CO₂)₂Ln(μ-CF₃CHO₂)AlR₂ · 2THF]₂ (Ln=Nd, Y, R=i-C₄H₉ (i-Bu); Ln=Eu, R=C₂H₅(Et); THF=tetrahydrofuran) were synthesized by the reaction of Ln(CF₃CO₂)₃ (Ln=Nd, Y) with HAl (i-Bu)₂ and of Eu(CF₃CO₂)₃ with AlEt₃, respectively. Their crystal structures were determined by X-ray diffraction at 233 K. [(μ-CF₃CO₂)₂Nd (μ-CF₃CHO₂)Al(i-Bu)₂ · 2THF]₂ (Nd–Al) and [(μ-CF₃CO₂)₂Y(μ-CF₃CHO₂)Al(i- Bu)₂ · 2THF]₂ (Y–Al) are isomorphous and crystallize in space group P 1 with a =12.441(3) Å [12.347(5) Å for Y–Al], b =12.832(3) Å [12.832(4) Å], c =11.334(3) Å [11.292(8) Å], α=104.93 (2)° [104.45(4)°], β=98.47(2)° [98.81(4)°], γ=64.60(2)° [64.30(3)°], R =0.519 [0.113], R _w=0.0532 [0.110], Z =1 and [(μ-CF₃CO₂)₂Eu(CF₃ CHO₂)AlEt₂ · 2THF]₂(Eu–Al) in space group P 2₁/ n with a =11.913(6) Å, b =14.051(9) Å, c =17.920(9) Å, α=101.88(11)°, β=γ=90°, R =0.0509, R _w=0.0471 and Z =2. The six CF₃CO     

甲酸甲酯生产甲酰胺催化新工艺的研究

研究了在常压下,由甲酸甲酯与ＮＨ３反应生产甲酰胺的催化新工艺,比较了不同反应器、加或不加催化剂。催化剂活性组分含量、催化剂粒度大小及装量等对反应的影响,并考察了不同反应温度、ＮＨ３流量、反应时间与甲酰胺收率的关系,结果表明用催化新工艺在２ｇ－Ｍ－１０催化剂上,加２０ｍＬ甲酸甲酯,ＮＨ４流量为４Ｌ／ｈ,反应温度７℃,反应２ｈ后,甲酰胺收率可达９９％。