Theory of chromatography of complex cyclic polymers: eight-shaped and daisy-like macromolecules

A theory of chromatography of eight-shaped, trefoil-shaped and daisy-like polymers is developed. For a model of an ideal chain in a slit-like pore exact equations and a number of approximate formulae for the distribution coefficient K of these polymers are derived. All modes of chromatography of complex macrocycles of arbitrary molar mass in both narrow and wide pores are covered by the theory. It is shown that complex macrocycles always elute after linear polymers and rings of the same contour length. The effective chromatographic radius of eight-shaped and daisy-like macromolecules, which determines retention in size-exclusion chromatography are calculated. The increase in the retention with molar mass is predicted for all types of macrocycles at the critical interaction condition. Non-monotonous molar mass dependences of K are found at pre-critical interaction. We simulate separation of complex cyclic polymers from linear and ring precursors, discuss possibilities to separate symmetric and asymmetric eights, and speculates on the use of chromatography for separating knotted and unknotted polymer rings. According to the theory, the chromatography under the critical and pre-critical interaction conditions is expected to be especially efficient in these and similar problems. Boundary conditions for the theory and its applicability to real systems are discussed.     

Lipase-catalyzed synthesis and properties of estolides and their esters

Eight lipases were screened for their ability to synthesize estolides from a mixture that contained lesquerolic (14-hydroxy-11-eicosenoic) acid and octadecenoic acid. With the exception ofAspergillus niger lipase, all 1,3-specific enzymes (fromRhizopus arrhizus andRhizomucor miehei lipases) were unable to synthesize estolides.Candida rugosa andGeotrichum lipases catalyzed estolide formation at >40% yield, with >80% of the estolide formed being monoestolide from one lesquerolic and one octadecenoic acyl group:Pseudomonas sp. lipase synthesized estolides at 62% yield, but the product mixture contained significant amounts of monoestolide with two lesquerolic acyl groups as well as diestolide. ImmobilizedR. miehei lipase was chosen to catalyze the esterification of mono-and polyestolide, derived synthetically from oleic acid, with fatty alcohols or α,ω-diols. Yields were >95% for fatty alcohol reactions and >60% for diol reactions. In addition, the estolide linkage remained intact through the course of the esterification process. Esterification of estolides improved the estolide’s properties—for example, lower viscosity and higher viscosity index—but slightly raised the melting point. Estolides and, particularly, estolide esters may be suitable as lubricants or lubricant additives.     

重组G145R HBsAg亲和纯化方法的建立及其应用

目的建立重组乙型肝炎病毒G145R变异HBsAg抗体亲和纯化方法。方法用抗-HBs单克隆抗体(D12- McAb)制备亲和层析胶,对2A8细胞(分泌G145R变异HBsAg)培养上清盐析物进行亲和纯化。采用SDS-PAGE、Western blot及ELISA,对纯化产物的纯度、特异性、含量和回收率进行鉴定,并与同法纯化的HBsAg阳性血清及r-wHBsAg提取物进行比较。结果D12-McAb对重组真核表达G145R变异HBsAg、HBsAg阳性血清及r-wHBsAS三者具有相似的亲和性,产物纯度分别为90.3%、95.2%和93.1%,回收率分别为43.3%、72.0%和66.4%。结论已成功地建立了重组G145R变异HBsAg抗体亲和纯化方法,为G145R变异以及其他HBV免疫逃逸变异感染的深入研究奠定了重要的技术基础。     

胺菊酯·高效氯氰菊酯气雾剂的气相色谱分析

介绍了 0 .2 8 %胺菊酯·高效氯氰菊酯气雾剂的气相色谱分析方法。选用 5 %SE - 30 ChromsorbWAW -DMCS(15 0～ 180um)色谱柱 ,以邻苯二甲酸二正辛酯为内标物进行定量分析测定 ,该方法简单、快速、准确、适用。结果表明胺菊酯和高效氯氰菊酯的标准偏差分别为 0 .2 4 %和 0 .11% ;变异系数分别为 0 .94 %和 1.74 % ;平均回收率分别为 99.6 4 %和 99.95 % ;线性回归系数分别为 0 .9999和 0 .9998。     

纤维素衍生化手性固定相的制备和对噻吗洛尔拆分

用超声方法合成了三(3,5-二硝基苯甲酰基)纤维素(CTNB)、三(4-溴苯甲酰基)纤维素(CTBB)、三(苯甲酰基)纤维素(CTB)、三(4-甲基苯甲酰基)纤维素(CTMB)、三(4-硝基苯甲酰基)纤维素(CTPB).将此类衍生化纤维素作为薄层色谱的手性固定相,结合展开剂的优化,对噻吗洛尔对映体进行拆分研究,并对衍生化取代基对拆分效果的影响以及对映体在手性固定相上的拆分机理进行了详细的探讨.     

离子色谱法测定配煤、焦炭和焦油中的氯含量

研究了用带电导检测器的离子色谱对配煤、焦炭和焦油中的Cl- 进行测定的方法。在YSA型8126A-4# 阴离子分离柱上用3.5mmol/LNa2CO3、5.3mmol/LNaHCO3做淋洗液对Cl-进行测定,方法简便快速。Cl-的检出限为2×10-6。该法也适用于F-、NO2-、NO3-、SO42-等的测定。     

Identification of some volatile compounds in the odor of fecal pellets of the rabbit,Oryctolagus cuniculus

A study has been made of the volatile constituents in the vapors collected from fecal pellets of wild rabbits,Oryctolagus cuniculus. Measurements of changes in the heart rates of adult male rabbits exposed to the effluent of a gas chromatographic capillary column were used to indicate the presence of compounds which may be of behavioral significance. Combined with the use of high-resolution columns in gas chromatography and gas chromatography-mass spectrometry, this approach has implicated several classes of compounds, including volatile fatty acids and phenols, which in certain absolute or relative concentrations may be involved in the formation of signals of territorial importance.     

丙二醇单甲醚丙酸酯合成体系的气相色谱分析

自行研制了氰乙基(25%,质量分数)甲基硅橡胶(XE-60)石英毛细管色谱柱。建立了对含游离酸的丙二醇单甲醚丙酸酯的色谱分析方法。该法具有分离效果好,分析速度快的优点。     

8─羟基喹啉─5─磺酸柱前衍生反相HPLC分离测定痕量Al（Ⅲ）、Co（Ⅲ）、Fe（Ⅲ）和Pd（Ⅱ）

本文采用８－羟基喹啉－５－磺酸（ＨＱＳ）为柱前衍生试剂，用含有１０ｍｍｏｌ·Ｌ－１的四丁基溴化铵（ＴＢＡ＋Ｂｒ－）、７．５×１０－５ｍｏｌ·Ｌ－１的ＥＤＴＡ和２０ｍｍｏｌ·Ｌ－１的ｐＨ５．６乙酸－乙酸钠缓冲溶液的甲醇－水（４５：５５，Ｖ／Ｖ）溶液为流动相，以Ｃ１８硅烷化载体为固定相，１６ｍｉｎ内分离测定了Ｃｏ（Ⅲ）、Ｆｅ（Ⅲ）、Ａｌ（Ⅲ）和Ｐｄ（Ⅱ）的ＨＱＳ的配合物、信噪比为３时，检出限分别为：Ｃｏ（Ⅲ）０．９ｐｐｂ、Ｆｅ（Ⅲ）１．５ｐｐｂ和Ｐｄ（Ⅱ）５．４ｐｐｂ，方法灵敏度高，干扰少，用于测定试剂级盐酸，硝酸和中国红茶样品中的这些离子，结果良好。     

15%田草灵高效液相色谱分析

采用Ｎｏｖａ－Ｐａｋ Ｃ１８不锈钢色谱柱进行反相液相色谱分析，以甲醇：水＝６５：３５（Ｖ／Ｖ）为注动相，以邻苯二甲醇二乙酯为内标物，用内标法测定田草灵除草剂中苄嘧黄隆和异丙甲草胺的含量，结果表明，各有效成分与内标物色谱峰分离完全，杂质无干扰，测定结果，苄嘧黄隆和异丙甲草胺的变异系数分别为０．７４％和１．０７％，回收率分别为９９．４％￣１００．８％和９９．１％￣１０１．３％。