水和土壤中LAS的提取及HPLC测定

<正> 1 引言合成洗涤剂中直链烷基苯磺酸盐(LAS)是目前生产和使用量最大的表面活性剂[1],同时也是环境中最常见、分布最广的有机污染物[2,3]。它可通过生活污水、垃圾及工业废水废渣等多种途径进入水体和土壤,造成了不同程度的环境污染[4,5]。准确、快速、经济地提取和测定环境样品中的LAS含量,是防治其污染的必要手段。目前水样中LAS的提取方法多为液-液提取法,土壤样品中LAS的提取多用索氏提取法。但这些方法步骤繁琐、费时,试剂消耗量大,且重现性不好[1]。本研究旨在建立一个快捷、准确、经济的水和土壤中LAS的提取和测定方法。 2 材料与方法

A spatial sampling optimization package using MSN theory

The density and distribution of spatial samples heavily affect the precision and reliability of estimated population attributes. An optimization method based on Mean of Surface with Nonhomogeneity (MSN) theory has been developed into a computer package with the purpose of improving accuracy in the global estimation of some spatial properties, given a spatial sample distributed over a heterogeneous surface; and in return, for a given variance of estimation, the program can export both the optimal number of sample units needed and their appropriate distribution within a specified research area. (C) 2010 Elsevier Ltd. All rights reserved.

北五味子不同炮制品中的木脂素类成分

研究北五味子炮制前后其中木脂素类成分的变化。采用电喷雾质谱(ESI-MS)以及高效液相色谱(HPLC)分别对经过不同方法炮制后的北五味子中木脂素类成分进行研究。北五味子经过不同方法炮制后,并没有新成分的生成,只是木脂素类成分含量有不同程度的变化。并对不同的炮制方法进行了比较。该方法准确、可靠,为北五味子不同炮制品的质量评价提供了一定的科学依据。

麻黄炮制条件的ESI-MS法优化

ESI-MS was used to optimize the Ephedra sinica refinement. The ratio of honey to drug is 20/100, and the ratio of water to honey is 1/2. The toast temperature is 80 ℃, and the toast time is 2 h. The change of Ephedra sinica after processing was given.

A quantitative HPLC method for determining lactide content using hydrolytic kinetics

A new method for quantitative analysis of lactide has been developed by applying chemical kinetics to a HPLC system. The most important advance is its practical approach to the quantification of analytes that are unstable in the HPLC mobile phase. In HPLC analysis, anhydrous mobile phases cannot separate lactide from impurities, and only mixtures of water and organic solvent can achieve effective separation. By selecting conditions for testing and studying the kinetics of lactide hydrolysis, extensive experiments revealed that lactide degradation can be treated as a pseudo-first-order reaction under the given HPLC conditions, and lactide content or purity can be quantitatively determined. This method is practical for measuring the purity of the intermediate lactide in polylactic acid (PLA) production and the lactide content in PLA.

麻黄附子甘草汤配伍过程中炮附子生物碱成分的变化研究

利用电喷雾串联质谱方法(ESI-MS/MSn)和内标法分析麻黄附子甘草汤方剂中二萜类生物碱种类和含量的变化,通过拆方研究了麻黄、甘草对附子生物碱的影响规律,揭示了麻黄附子甘草汤的配伍内涵。研究表明,麻黄、甘草单独与炮附子配伍时能够通过化学和物理作用减少热解型单酯型生物碱的含量,并生成脂型生物碱,但方剂组合后有效成分热解型单酯型生物碱的含量增加。结合初步药效学实验表明,热解型单酯型生物碱是具有明显的抗炎作用,说明炮附子在复方中发挥抗炎作用的主要成分可能为热解型单酯型生物碱,同时复方的整体配伍利于有效成分的转化。

Evaluation of Effects of Bivalent Cations on the Formation of Purine-rich Triple-Helix DNA by ESI-FT-MS

The GGA triplet repeats are widely dispersed throughout eukaryotic genomes. (GGA)n or (GGT)n oligonucleotides can interact with double-stranded DNA containing (GGA:CCT)n to form triple-stranded DNA. The effects of 8 divalent metal ions (3 alkaline-earth metals and 5 transition metals) on formation of these purine-rich triple-helix DNA were investigated by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FT-MS). In the absence of metal ions, no triplex but single-strand, duplex, and purine homodimer ions were observed in mass spectra. The triple-helix DNA complexes were observed only in the presence of certain divalent ions. The effects of different divalent cations on the formation of purine-rich triplexes were compared. Transition-metal ions, especially Co2+ and Ni2+, significantly boost the formation of triple-helix DNA, whereas alkaline-earth metal ions have no positive effects on triplex formation. In addition, Ba2+ is notably beneficial to the formation of homodimer instead of triplex.

等离子体光辐射-磁场综合作用处理种子对人参中皂苷含量的影响

采用紫外可见分光光度法、ESI-MS(电喷雾质谱)与HPLC-UV(高效液相色谱)测定技术分析了等离子体种子处理机处理人参种子对所栽培人参中人参皂苷含量的影响。结果发现,人参种子受到等离子体与梯度磁场综合作用处理后,培育出的人参其总皂苷含量随磁化电流强度的改变呈现近似的正态分布。其中,在磁化线圈电流强度为1.1~1.5 A处理种子后,栽培的人参中总皂苷含量较高。建立了电喷雾质谱分析人参提取物中人参皂苷的半定量方法,方法便捷地反映了未处理及处理后的人参种子所栽培的人参中皂苷成分的含量变化。

复方板蓝根颗粒水提部位的ESI-MS指纹图谱研究

Sialic acid and lysine as an internal standard substance,the ESI-MS fingerprinting of extracts of Compound Indigowoad Root Granule which from different origin was studied.The fingerprinting was obtained with better precision and reproducibility.This work can provide a reference for the quality control of Compound Indigowoad Root Granule.

ESI-MS法研究白芍炮制前后化学成分的变化

ESI-MS analytical method was employed to study extracts of unprocessed and processed Radix Paeoniae alba.The results of the experiments prove that different processed methods is making a certain different influence on the contents of chemiacl components in Radix Paeoniae alba.This method is simple and accurate.It can be used for analyse of Traditional Chinese Medicine(TCM).

Purification, sequencing and biological activity of polypeptide from velvet antler

The velvet antler polypeptide CNT14 was extracted and purified by gel filtration, ion exchange chromatography and RP C, which showed a single peak in HPLC chromatography and a single band in SDS-PAGE. The molecular weight measured by MALDI/TOF/MS spectrum was 1479. 9028. The polypeptide consisted mostly of Glu, Leu, Val, Pro. The amino acid sequence of the polypeptide was detected with ESI-MS/ MS, and the sequence was E-P-T-V-L-D-E-V-C-L-A-H-G-P. The experiments of biological activity of polypeptide CNT14 in vivo were carried out, and the results show that CNT14 has stimulant effects on the growth of rat HT22 cells. Then we produced the polypeptide CNT14 according the amino acid sequence by solid phase synthesis, confirmed the sequence of the polypeptide to be consistent with the amino acid sequence of polypeptide CNT14 which was separated from the velvet antler.

Bimolecular quadruplexes and their transitions to higher-order molecular structures detected by ESI-FTICR-MS

Four individual quadruplexes, which are self-assembled in ammonium acetate solution from telomeric sequences of closely related DNA strands - d(G(4)T(4)G(4)), d(G(3)T(4)G(4)), d(G(3)T(4)G(3)), and d(G(4)T(4)G(3)) - have been detected in the gas phase using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS). The bimolecular quadruplexes associate with the same number of NH4+ in the gas phase as NMR shows that they do in solution. The quadruplex structures formed in solution are maintained in the gas phase. Furthermore, the mass spectra show that the bimolecular quadruplexes generated by the strands d(G(3)T(4)G(3)) and d(G(4)T(4)G(3)) are unstable, being converted into trimolecular and tetramolecular structures with increasing concentrations of NH4+ in the solution. Circular dichroism (CD) spectra reveal structural changes during the process of strand stoichiometric transitions, in which the relative orientation of strands in the quadruplexes changes from an antiparallel to a parallel arrangement. Such changes were observed for the strand d(G(4)T(4)G(3)), but not for the strand d(G(3)T(4)G(3)). The present work provides a significant insight into the formation of various DNA quadruplexes, especially the higher-order species.

Structural features of the L-argininamide-binding DNA aptamer studied with ESI-FTMS

The 24-mer DNA aptamer of Harada and Frankel ( Harada, K.; Frankel, A. D. EMBO J. 1995, 14, 5798-5811) that binds L-argininamide (L-Arm) was studied by electrospray ionization Fourier transform mass spectrometry (ESI-FTMS). This DNA folds into a stem and loop such that the loop is able to engulf L-Arm. As controls, two derivatives of the same base composition, one with the same stem but a scrambled loop and the other with no ability to form a secondary structure, were studied. The two DNAs that could fold into stem-loop structures showed a more negatively charged distribution of ions than the linear control. This tendency was preserved in the presence of ligand; complexes expected to have more secondary structure had ions with more negative charges. Distinct species corresponding to no, one, and two bound L-Arm molecules were observed for each DNA. The fractional peak intensities were fit to a straightforward binding model and binding constants were obtained. Thus, ESI-FTMS can provide both qualitative and quantitative data regarding the structure of DNA and its interactions with noncovalent ligands.

Analysis of strychnos alkaloids using electrospray ionization Fourier transform ion cyclotron resonance multi-stage tandem mass spectrometry

The fragmentations of four strychnos alkaloids have been investigated by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) in the positive ion mode. Experiments using multi-stage tandem mass spectrometry (ESI-FT-ICR-MSn) allowed us to obtain precise elemental compositions of product ions at high mass resolution. The experimental data demonstrated that the nitrogen bridge and the coordinated oxygen atom on the nitrogen bridge in the alkaloid compounds were the active sites in the MS2 fragmentations. The loss of CH3 or the OCH3 group in those alkaloids, which have an OCH3 substituent, was the dominant fragmentation mode in the MS3 fragmentations. Logical fragmentation schemes for strychnos alkaloids have been proposed and these should be useful for the identification of these compounds.