异色异构

A developed high performance liquid chromatography method was introduced to determine the isomer s of β-carotene.

本研究发展并改进了以C30柱分离检测β-胡萝卜素异构体的高效液相色谱方法。

UV and HPLC were used for the first time to study the photo-cis-trans isomerism in dilute DNS solution.

首次采用紫外光谱和高压液相色谱初步研究了4，4'-二硝基二苯乙烯-2，2'-二磺酸稀溶液中的光致顺反异构现象。

The conclusions were as follows: theνO-H andνC=O IR absorption maxima shifted towards higher wave numbers after imprinting 17β-estradiol on TFMAA-co-TRIM copolymer with the red shift of theνO-H groups being apparent after precipitation polymerization for 16h while that forνC=O groups being observed after polymerization for 24h. A strong interaction between TFMAA and 17β-estradiol was confirmed by the high selectivity for 17β-estradiol, as indicted by the values of the separation factor of isomers of 17β-estradiol/17α-estradiol (2.28) and the imprinted factor (3.01). Particle diameter of TFMAA-co-TRIM polymer was between 300 nm and 1.5μm, which suited well for solid phase sorbent throughout at low column pressure. The recognition of imprinting TFMAA-co-TRIM polymer for sterol molecules was driven by enthalpy eluted with acetronitile, and low temperature was in favor of the separation of sterol structure analogues on imprinting column. TFMAA-co-TRIM polymer possessed of determinate anti-heat stability, with melting point beginning at 255.84℃, Tp=257.40℃, control TFMAA-co-TRIM polymer and imprinting TFMAA-co-TRIM polymer were respectively decompounded at 267.79℃and 343.11℃, and solid micro-extraction noddle prepared by the special polymerization also showed definite recognition for 17β-estradiol by GC/MS detecting at 270℃. By selection of various washing and elution solvents, elution reagents of close polymerization system were of more advantage in template molecules retention and recognition on molecularly imprinted solid phase extraction column. At a certain extent, progesterone, 17α-estradiol, 17β-estradiol and 4-androstene-3, 17-dione could be intercepted on the MISPE column. Especially, MISPE had high selectivity for progesterone, and imprinting TFMAA-co-TRIM polymer could achieve adsorption balance within 50 min by absorption kinetics test for 17β-estradiol. However, MISPE column showed better selectivity and enrichment property for 17β-estradiol than C18 and CSPE columns according to the data from HPLC and GC/MS analyses. Recovery of 17β-estradiol on MISPE column was up to 85.5% while when prime extracting solution of milk powder was sampled, the recovery of CSPE and C18 columns were 43.7% and 30.7%, respectively.

通过研究阐明：紫外聚合产物TFMAA-co-TRIM中的νO-H振动吸收峰在聚合16h后红移，νC=O振动吸收峰在聚合24h后红移；TFMAA-co-TRIM对雌二醇异构体的印迹因子达到了3.01，α为2.28，优于其它功能单体参与得到的聚合物识别特性；TFMAA-co-TRIM聚合物粒径介于300 nm至1.5μm之间，作为色谱固定相具有良好的通量和低的柱压；在乙腈流动相中，TFMAA-co-TRIM分子印迹固定相的分离过程主要被焓驱动，低温有利于分子印迹固定相分离甾醇结构类似物；TFMAA-co-TRIM分子印迹聚合物在255.84℃时开始熔融，Tp=257.40℃，聚合物CP的降解温度在267.79℃，MIP降解温度在343.11℃，制备的固相微萃取头初步经GC/MS 270℃的耐热性测定；不同的洗提溶剂筛选证明了选择接近聚合溶剂的洗脱体系更有利于MISPE发挥识别效应；分子印迹固相萃取柱对孕酮、17α-雌二醇、17β-雌二醇和雄烯二酮都具有不同程度的保留特性，可作为此类化合物的吸附材料，特别对孕酮强保留的富集特性，可作为孕酮的选择性识别吸附剂，其分子印迹聚合物对17β-雌二醇的吸附动力学测定显示在50 min内基本达到吸附平衡，具有作为传感器核心敏感材料的潜力；对比萃取奶粉中17β-雌二醇性能，MISPE柱比非分子印迹固相萃取柱和C18柱具有更高的保留，回收率依次为85.5%，43.7%和30.7%。

The ee is assessed by chiral GC and/or polarimetry.

对映异构体过量值由手性气相色谱法和/或旋光测定法测得。

Serum levels of ADMA and its stereoisomer, symmetrical dimethylarginine, were determined using high-performance liquid chromatography.

使用高效液相色谱法测定ADMA及其立体异构体对称二甲基精氨酸的血清浓度。

OBJECTIVE To establish a method for determination of levo-enantiomer in Tolterodine Tartrate by HPLC.

目的建立高效液相色谱法测定酒石酸托特罗定中左旋异构体的方法。

A separation model of ionizable and neutral enantiomer s with cyclodextrin-sodium dodecyl sulphate micellar electrokinetic chromatography was established.

建立了环糊精-十二烷基硫酸钠胶束电动色谱中可电高及电中性-光学异构体的分离模型。

High speed countercurrent chromatography was successfully used for the separation and preparation of isomeric compounds .

应用高速逆流色谱法对同分异构体的分离纯化进行研究。

Sequences analysis indicated 26 unique cDNA sequences that encoded putative proteins showing similarities to HL35 antigen U, hlim3, heat shock protein, NADH dehydrogenase subunit 1 and calreticulin of H. longicornis, disulfide isomerase of Ambiyomma variegatum and Ixodes scapularis.

结果表明：在长角血蜱雌蜱唾液腺cDNA表达文库中获得26个长角血蜱免疫相关cDNA序列，其编码蛋白与长角血蜱HL35、黏附素hlim3假定蛋白、热休克蛋白、NADH脱氢酶、钙网蛋白以及杂色花蜱和肩突硬蜱的二硫异构酶等具有同源性。

PK values of 3-ethoxy-N-desmethyldiazepam (3-EtO-NDZ) in ethanol and acetonitrile containing various concentrations of sulfuric acid, determined by spectrophotometry and spectropolarimetry, were found to be 3.4 and 0.63 respectively. Temperature dependent racemization of enantiomeric 3-EtO-NDZ in ethanol containing various acid concentrations was studied by monitoring changes of ellipticity at 365 nm as a function of time on a spectropolarimeter.

3-乙氧基－N去甲基安定（3-EtO-NDZ；diazepam=安定）在含不同硫酸浓度的乙醇和乙腈中的pK值用光谱法和旋光光谱法作了测定，其结果分别为3.4和0.63.3-EtO-NDZ之对映异构体在含各种不同酸浓度的乙醇中与温度相关的消旋过程，用旋光光谱仪选择其圆二色谱在365nm波长处强度的改变为时间函数的方法作了测定。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐