新型内表面反相限进填料的制备与评价

通过在硅烷化硅胶内表面和外表面分别键合己胺和聚乙烯醇,制备了能够在线直接进样分析生物样品的新型内表面反相限进填料。采用元素分析、电镜观察对该限进填料的结构进行了表征。以普萘洛尔、阿替洛尔、苯巴比妥、卡马西平作溶质探针,并以Merck公司生产的限进填料柱作参比,对合成的限进填料的色谱性能进行了研究。研究结果表明,所制备的限进填料有较好的蛋白质排阻能力、富集能力和反相色谱性能,能同时实现排阻生物大分子杂质和富集小分子被分析物的功能,可作为在线、快速直接进样检测分析生物样品的预处理柱,适用于普萘洛尔血浆的直接进样分析。     

限进介质烷基-二醇基硅胶(ADS)的制备

 烷基 二醇基硅胶 (ADS)系限进介质的一种 ,可用于含生物大分子的复杂生物样品的直接进样与分析。一种新的、非常经济的方法可用于烷基 二醇基硅胶的制备。首先 ,将γ 环氧丙基氧丙基三甲氧基硅烷基键合至微孔硅胶上 (粒度 5 μm ,孔径 6nm)以制备环氧基硅胶 ,再令环氧基硅胶与硬脂酸在有机溶液中进行反应以制备酯型十八烷基反相填料。将制得的反相填料填充至色谱柱中 ,并令含有酯酶的溶液通过色谱柱。通过酶解作用可将硅胶表面的酯基除去 ,而硅胶的内孔表面仍保持疏水特性不变 ,这是由于硅胶上的小孔对酶分子具有体积排除作用。     

杂多酸的固载化Ⅲ．溶剂对H_4SiW_（12）O_（40）·24H_2O在活性

研究了Ｈ＿４ＳｉＷ＿（１２）Ｏ＿（４０）·２４Ｈ＿２Ｏ（ＳｉＷ＿（１２））在水、乙醇、乙酸、乙酸丁酯中在活性炭上的吸附得出，活性炭微孔结构对ＳｉＷ＿（１２）在其表面的吸附起着分子筛作用。水溶剂化的ＳｉＷ＿（１２）分子可顺利进入活性炭１．７ｎｍ左右的微孔，而其它溶剂化的ＳｉＷ＿（１２）分子，则需较大的孔径。提出了ＳｉＷ＿（１２）在活性炭表面吸附的微孔中孔扩散模型。     

高亲水性强阳离子交换色谱填料的制备及其在蛋白质分析中的应用

以具有双孔结构的聚甲基丙烯酸环氧丙酯(PGMA)微球为基质,以葡萄糖进行表面亲水改性,制备了强阳离子交换色谱填料,并将其用于复杂生命体系中生物大分子的快速而高效的分离、分析与纯化。葡萄糖亲水改性增进了填料的生物相容性,提高了蛋白质样品的回收率;双孔结构及较高的比表面积赋予填料良好的柱渗透性和样品负载量。以标准蛋白质为样品,考察了该填料对生物样品的分离性能。以100 mm×4.6 mm的色谱柱分离4种蛋白质,在6 min内实现了基线分离;以溶菌酶为样品,填料的吸附容量为39.5 g/L,在蛋白质快速分离纯化分析中显示了良好的应用前景。     

微乳液组成对毛细管微乳液电动色谱的影响

研究了一组电中性芳香族化合物的毛细管微孔液电动色谱分离，考察分离介质微乳液的组成对电动色谱保留时间的影响，实验结果表明，各芳香化俣物的保留时间均随表面活性剂２增加而增长；内相和助表面活性剂对有，无亲水基团入香化合物的保留时间有不同的影响规律，选用微乳液组成为８０ｍｍｏｌ／Ｌ正庚烷－１２０ｍｍｏｌ／ＬＳＤＳ－９００ｍｍｏｌ／Ｌ正丁醇－１０ｍｍｏｌ／Ｌ硼砂，样品在１４ｍｉｎ内达到完全分离，理论板数为３     

中孔MCM—41分子筛在微孔沸石ZSM—5上附晶生长的研究

首次在微孔沸石ＺＳＭ５表面进行了ＭＣＭ４１分子筛的附晶生长，并首次提出中孔材料ＭＣＭ４１分子筛静电组配理论的新形式（ＸＳ＋Ｉ）；同时利用ＸＲＤ、ＴＥＭ、ＢＥＴ等测试手段表征了合成样品，并讨论了微孔沸石表面附晶生长中孔分子筛ＭＣＭ４１的合成化学，考察了Ｆ离子效应、ｐＨ值及表面活性剂ＣＴＡＢ（十六烷基三甲基溴化铵）的影响。     

STUDIES ON MACROCYCLIC DITERPENOIDS（Ⅻ）──A Convergent and Stereoselective Synthesis of Sarcophytol－Q Precursor──（11S）－3，7，11，15－Tetramethyl－11－Hydroxy－14－Oxo－3E，7E，12E－Hexadecatrienal

ＳＴＵＤＩＥＳＯＮＭＡＣＲＯＣＹＣＬＩＣＤＩＴＥＲＰＥＮＯＩＤＳ（Ⅻ）──ＡＣｏｎｖｅｒｇｅｎｔａｎｄＳｔｅｒｅｏｓｅｌｅｃｔｉｖｅＳｙｎｔｈｅｓｉｓｏｆＳａｒｃｏｐｈｙｔｏｌ－ＱＰｒｅｃｕｒｓｏｒ──（１１Ｓ）－３，７，１１，１５－Ｔｅｔｒａｍｅｔ...     

Characterization of Oxygen Species on MgO(100) Surface by XPS andSRPES

ＣｈａｒａｃｔｅｒｉｚａｔｉｏｎｏｆＯｘｙｇｅｎＳｐｅｃｉｅｓｏｎＭｇＯ（１００）ＳｕｒｆａｃｅｂｙＸＰＳａｎｄＳＲＰＥＳＪｉａｎＷｅｎＤＡａｎｄＳｈｉＫｏｎｇＳＨＥＮ（ＲｅｓｅａｒｃｈＩｎｓｔｉｔｕｔｅｏｆＱｉｌｕＰｅｔｒｏｃｈｅｍｉｃａｌＣｏ．，...     

STUDIES ON MACROCYCLIC DITERPENOIDS（XI）──A Convergent and Stereoselective Synthesis of Cembrenene Precursor－4，10－Dimethyl－7－Isopropenyl－14－Oxo－3Z，5E，10E－Pentadecatrienal

ＳＴＵＤＩＥＳ　ＯＮ　ＭＡＣＲＯＣＹＣＬＩＣ　ＤＩＴＥＲＰＥＮＯＩＤＳ（ＸＩ）──Ａ　Ｃｏｎｖｅｒｇｅｎｔ　ａｎｄ　Ｓｔｅｒｅｏｓｅｌｅｃｔｉｖｅ　Ｓｙｎｔｈｅｓｉｓ　ｏｆ　Ｃｅｍｂｒｅｎｅｎｅ　Ｐｒｅｃｕｒｓｏｒ－４，１０－Ｄｉｍｅｔｈｙｌ－７－Ｉ...     

^23NaMASNMR研究预处理对分子筛晶内结构的影响

使用固体高分辨＾３２ＮａＭＡＳＮＭＲ技术研究了ＮａＺＳＭ－５分子筛经不同预处理后晶体内部结构的变化。结果表明，ＮａＺＳＭ－５分子筛中存在着两类钠质点，Ｎａ＾＋在未处理的样品中与焙烧处理４ｈ后的样品中受到的电场梯度大不相同。Ｚｎ＾２＋进入了ＮａＺＳＭ－５内孔道并占据了部分阳离子位置，Ｇａ＾３＋未进入ＮａＺＳＭ－５内孔道，主要位于沸石外表面，并与外表面上Ｎａ＾＋发生了部分交换，最后，讨论了Ｇａ＾３＋，     

The Internal Surface Reverse Phase. Concepts and Applications

Abstract

Patented in 1985, introduced commercially in 1986, internal-surface reversed phase (ISRP) supports have attracted wide attention. ISRP supports allow the analysis of serum and plasma samples by high pressure liquid chromatography (HPLC) without requiring the prior removal of protein. Proteins cannot enter the pores of ISRP supports and are not adsorbed by ISRP outer surfaces; proteins pass right through ISRP HPLC columns. Therefore, the number of serum injections that given ISRP-guarded ISRP columns can receive runs into the thousands; ISRP columns nicely lend themselves to automation. ISRP indifference to proteins is complemented by the remarkable selectivity toward drugs of its stationary phase, glycine-phenylalanine-phenylalanine (GFF), a selectivity that recently has been shown to extend to peptides. More recently still, it has been shown that ISRP columns can be used to analyze both the free and the bound forms of drugs, even distinguishing among different bound forms. A potential new intrinsically monomeric GFF shows improved retention and surprisingly high chromatographic efficiency.     

Characterization of internal surface reversed-phase silica supports for liquid chromatography

Internal surface reversed-phase (ISRP) supports synthesized from commercially available porous silica particles with a variety of nominal pore diameters and specific surface areas are characterized with regard to physical and chromatographic properties. Bonded phase coverage, pore size, capacity and efficiency measurements are made upon the various ISRP supports in order to evaluate the effect that the physical properties of silica have upon the chromatographic performance of ISRP packings. In addition, various models that describe the pore structure of silica supports are discussed.     

Synthesis and characterization of novel internal surface reversed-phase silica supports for high-performance liquid chromatography

An original synthetic method was developed for the preparation of a family of six novel deactivated restricted-access materials (RAMs), belonging to the group of the internal surface reversed-phase (ISRP) supports. The supports (ISRP-RAM phases A-F) have an alkyl-chain (14 methylenes) with two embedded ureido groups bound only to the internal surfaces of the porous silica, and polyvinyl alcoholic groups (PVA, 100,000-->22,000 molecular weight) chemically bound to the external surfaces. The average pore diameters of the prepared ISRP-RAM supports, calculated by inverse size-exclusion chromatography, ranged between 49 A and 88 A, and were able to exclude macromolecules heavier than about 24000 Da (such as serum proteins) from the pores. The novel supports were designed for the determination of a semi-synthetic anticancer drug of the camptothecin family in human plasma, but they represent universal ISRP-RAM supports not limited to such class of compounds.     

Direct analysis of whole blood by internal surface reversed-phase chromatography: an examination of the binding and metabolism of technetium dioxime complexes.

We have developed a method using internal surface reversed-phase (ISRP) packing for rapid on-line separation of small hydrophobic compounds from cellular whole blood components. This is achieved by the use of 75-microns ISRP chromatographic material packed into a small high-performance liquid chromatographic (HPLC) column, in conjunction with column switching. We have applied this analytical method to study the in vitro metabolism of 99mTc-BATO (boronic acid adducts of technetium dioxime) cerebral and myocardial perfusion tracers in whole blood. The results from the ISRP procedure were compared with a conventional centrifugation method of analysis. This novel HPLC methods provides a rapid, convenient and reliable method for the analysis of radioactive and non-radioactive lipophilic components in whole blood.     

Application of an internal surface reversed-phase column for the automated determination of flucycloxuron residues

A liquid chromatographic column-switching system for the automated determination of flucycloxuron, a benzoylphenylurea pesticide, in crop and environmental matrices is described. The system consists of an internal surface reversed-phase (ISRP) column, a phenyl-bonded precolumn and an analytical reversed-phase (RP) C₁₈ column. Sample extracts are evaporated to dryness and dissolved in the mobile phase of the ISRP column. An aliquot of this solution is injected into the column-switching system. Clean-up, with regard to removal of large molecules, is performed on the ISRP column. The flucycloxuron fraction from the ISRP column is concentrated on the phenyl-bonded precolumn. Additional clean-up can be performed by washing the precolumn. Finally, the compound is desorbed from the precolumn and separation and determination of the Z- and E-isomers of flucycloxuron are performed with the analytical RP-C₁₈ column using UV detection at 254 nm. The total analysis time required is 40 min. The reproducibility of the method obtained with the column-switching system, expressed as relative standard deviation, varies between 3.7 and 10% for apple, strawberry, citrus and soil samples for flucycloxuron levels between 0.04 and 0.33 mg/kg. The system showed no loss of analytical performance after more than 300 analyses.     

Changes in density and surface tension of water in silica pores

 The density and surface tension of water in small pores of silicas have been investigated. These physical properties of water in the pores were calculated from a comparison of pore volumes and pore radii which were estimated from adsorption and desorption isotherms of nitrogen and water. Below a pore radius of about 5 nm both the density and the surface tension of water in the pores were smaller than those of the bulk liquid and decreased with a decrease in pore size. The density of water in the pores decreased with an increase in the concentration of surface hydroxyl groups. Similarly the surface tension of water in the pores is influenced by the surface hydroxyl groups. Anomalous changes in the density and surface tension of the water in the pores are attributed to the interaction of water molecules with surface hydroxyl groups and hydrogen-bond formation among water molecules. Received: 20 April 1999 Accepted in revised form: 17 November 1999     

The Use of Internal Surface Reversed-Phase Packing for the Solid Phase Extraction of Drugs from Serum

Abstract

The utilization of Internal Surface Reversed Phase (ISRP) packing as a solid phase extraction (SPE) matrix was investigated. Evaluation of the relative retention of nineteen medicinal agents on ISRP material was monitored using HPLC. The effects of altering pH and/or buffer concentration on retention were further studied using verapamil, phenelzine and tamoxifen as model compounds. Spiked serum samples containing the model compounds plus amitriptyline were also subjected to ISRP-SPE and HPLC. Verapamil, phenelzine, and tamoxifen were all strongly retained on ISPR as pH increased. The buffer concentration of the sample was not as critical on retention of these compounds as pH. Verapamil was quantitatively recovered from spiked serum samples (103 /pm 8.5%, n = 6), with a limit of detection of 10 ng/mL using fluorescent detection (γex = 280 nm, γem = 310 nm). Amitriptyline recovery was also quantitative (99.0/pm 5.3%, n = 6), and its limit of detection was 10 ng\mL employing short wavelength UV detection (γ = 214 nm). The ISRP packing as an SPE matrix failed to adequately disrupt the binding of either phenelzine or tamoxifen from serum proteins; therefore, recoveries of these compounds were poor (<50%). A comparison of ISRP to conventional C18 and C2 SPE columns indicated that the ISRP packing eliminated interferences as well or better than the conventional columns.     

Multidimensional high-performance liquid chromatography on Pinkerton ISRP and RP18 columns: direct serum injection to quantify creatinine.

A two-dimensional high-performance liquid chromatographic method for the determination of creatinine with direct serum injection without sample pretreatment has been developed. The column-switching technique allowed a switch from columns packed with internal surface reversed-phase (ISRP) material to columns of almost any other material, even if the eluents necessary in a particular case do not appear to be directly compatible. A Pinkerton ISRP column, which stands out because of its very good stability when loaded with undiluted serum samples, was used as precolumn. The creatinine-containing fraction was switched to a reversed-phase Shandon RP18 column and was focused there by alteration of the eluent from pH 6.5 to phosphoric acid-ion-pair reagent. The separation occurs via a pH gradient, with ultraviolet detection at 234 nm. This method stands out particularly for its good long-term stability, simple sample handling without pretreatment, high selectivity, a broad linearity (0.3-30 mg/dl creatinine), good reproducibility (inter-assay coefficient of variation less than 3%) and high recovery (97-100%) relative to values obtained with gas chromatography-mass spectrometry.     

FTIR Thermal Analysis on Anilinepropylsilica Xerogel

FTIR thermal analysis was used for a hybrid xerogel, anilinepropylsilica, obtained from three different organic precursor amounts, using HF and NaF as catalysts in the sol–gelprocess. The aniline ring vibrational mode at 1500 cm⁻¹ of attached aniline groups was used to obtain the relative aniline content in the xerogel materials after being submitted to thermal treatment in the temperature range from 100 to 400°C. This technique allowed to evaluate the thermal stability of organic phase. The organic coverage on the surface and the fraction of trapped organic groups in closed pores can also be evaluated. This revised version was published online in August 2006 with corrections to the Cover Date.     

Synthesis of Large‐Pore ECNU‐19 Material (12 × 8‐R) via Interlayer‐Expansion of HUS‐2 Lamellar Silicate

A large‐pore ECNU‐19 material with unique pore system consisting of 12‐ring (12R) pore channels intersected by 8R channels was post‐synthesized via interlayer‐expansion of HUS‐2 lamellar silicate with silylating agent of 1,3‐dimethyltetramethoxydisiloxane (DMTMDS). In consideration of the fact that the HUS‐2 precursor possessed a special structure with a malposition of the neighboring layers as well as silicon vacancies on layer surface, a “detemplating disassembly – intercalation reassembly – silylation” strategy was proposed to realize a successful interlayer‐expansion and structural amending. An acid treatment was firstly performed to remove a part of the structure‐directing agent molecules, which favored the following intercalation by bulk organic species. The intercalation not only rearranged the relative position of up‐down layers but also provided enough interlayer space for the insertion of dimeric silane molecules. Two –OH groups attached to one silicon atom of the silane molecule reacted with two close silanols on the up‐surface layer, while the other two –OH groups condensed with two silanols on the down‐surface layer, which then connected the two layers via ‐Si‐O‐Si‐ pillars and constructed new 12R pores along a axis and 8R pores along c axis, respectively.