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1.
用双-(6-氧-间羧基苯磺酰基)-β-环糊精作为手性选择剂,制备了手性HPCE整体柱,采用正向高效毛细管电泳法(HPCE)拆分了非衍生化的D,L-苯丙氨酸(D,L-phenylalanine),考察了缓冲液浓度、pH值、分离电压等因素对苯丙氨酸对映体保留特性和分离度的影响,探究了分离的最佳条件.结果表明:在最佳条件下,对映体分离度达到4.46,建立了一种高效的苯丙氨酸两对映体分离分析的新方法.  相似文献   

2.
建立了基于手性毛细管柱直接测定α-苯乙醇对映体含量的气相色谱法.采用日本岛津GC-2010气相色谱仪和CP Chirasil-DEX CB(25 m×0.25 mm)色谱柱,控制柱温为108℃,载气(N2)流量为1.9 mL/min,在此条件下α-苯乙醇手性对映体峰均达到基线分离.选择正十二烷作为内标物测定不同浓度α-苯乙醇,得到标准曲线,其线性(相关系数R=0.999 3)和重复性(RSD<1%)均很好.将该法用于手性催化剂Pd-CS/SiO2和Pd-CS/MCM-48催化苯乙酮氢转移反应产物α-苯乙醇手性对映体含量的分析,可进行高选择性手性催化剂的筛选,实现了对催化剂制备及反应条件的优化.  相似文献   

3.
采用双-(6-氧-间羧基苯磺酰基)-β-环糊精手性HPCE整体柱对药物氧氟沙星手性拆分,在高效毛细管电泳仪上,考察了缓冲液浓度、pH值、分离电压、进样量对分离度的影响.结果表明:在pH 4.0,浓度为50 mmol/L的Tris-磷酸缓冲液中进样20 s,工作电压25 kV,检测波长254 nm条件下,氧氟沙星对映体得到基线分离,分离度达到7.72.氧氟沙星对照品浓度在(2~6)×10-9 g/L,前峰峰高与浓度的线性相关系数r=0.9804,后峰峰面积与浓度的线性相关系数r =0.9872.  相似文献   

4.
以双-[-6-氧-(-2-间羧基苯磺酰基-丁二酸-1,4-单酯-4-)-]-β-环糊精(β-CD-B2)为手性添加剂在高效毛细管电泳(HPCE)中分离布洛芬,考察了缓冲溶液硼砂的浓度、pH值,手性添加剂β-CD-B2的浓度,分离电压对布洛芬手性异构体分离的影响.结果8min内实现了对映体的基线分离,最佳分离条件下分离度Rs为4.26.布洛芬对映体分离的前峰线性范围为0.0538~0.942g/L,后峰线性范围为0.178~0.942g/L.在分离布洛芬的最佳条件下,可同时分离布比卡因和布洛芬2种手性药物的混合溶液.  相似文献   

5.
用双[-6-氧-(3-脱氧柠檬酸单酯-4)]-β-环糊精为手性流动相添加剂,以有机弱酸的形式和三乙胺组成缓冲体系,在高效液相色谱(HPLC)中实现了头孢氨苄对映体的手性拆分.结合碳18硅胶键合(ODS-BP)柱为固定相,该缓冲液与不同比例乙腈混合形成流动相,考察了流动相配比、pH值、手性流动相添加剂浓度等因素对头孢氨苄2对对映体手性分离的影响.结果表明:在pH 8.8,流速0.6 mL/min,检测波长310 nm,添加剂浓度为5.0 mmol/L缓冲液的最佳条件下,可实现头孢氨苄4个对映异构体色谱峰的基线分离,最佳条件下4峰中相邻两峰分离度Rs分别为3.41、5.34和8.93.  相似文献   

6.
HPLC测定帕金森模型小鼠脑中D-丝氨酸的含量   总被引:1,自引:1,他引:0  
以邻苯二甲醛(OPA)-N-异丁酰基-D-半胱氨酸(IBDC)为手性衍生试剂,醋酸钠-甲醇-乙腈混合液为流动相,采用梯度洗脱,荧光检测,建立了测定生物样品中微量D-丝氨酸(D-Ser)的高效液相色谱法.Set对映体在20 min内完全分离.D-Ser在30~1 500 nmol/L时,其浓度与峰面积呈良好线性关系(R=0.999 5).当信噪比为3(S/N=3)时,D~Ser的检出限为10 nmol/L.将方法运用于帕金森病(Parkinson's disease,PD)模型小鼠中脑及大脑皮质中D-Ser含量的测定,结果表明,模型组脑组织中D-Ser的含量与对照组相比,整体呈显著下降趋势,推测D-Ser可能参与了PD的发病机制.  相似文献   

7.
利用亲和毛细管电色谱整体柱对色氨酸对映体进行了手性拆分研究.利用溶胶-凝胶法制备了壳聚糖/硅胶复合基质毛细管整体柱,然后采用戊二醛交联柱上键合牛血清白蛋白(BSA)得到亲和毛细管整体柱,以毛细管电色谱(CEC)模式分离色氨酸对映体,考察了缓冲液pH、浓度及有机修饰剂含量对分离过程的影响.在缓冲液的浓度为20 mmol/L,pH 7.5时,色氨酸对映体分离效果良好,分离度为2.44.  相似文献   

8.
以双[-6-氧-(-3-间硝基苯磺酰基-丁二酸-1,4单酯)-4-]-β-环糊精键合全多孔硅胶基质为高效液相色谱固定相,以正相和反相模式对药物扑尔敏进行手性分离.考察了流动相中配比、pH值对分离度的影响.结果表明:正相模式最佳条件下分离度Rs=1.37;反相模式最佳条件下分离度Rs=10.58,扑尔敏浓度为0.000~1.367mg/mL,前后峰峰高与浓度均呈线性关系,线性相关系数r均为0.9985.峰面积与浓度的线性相关系数r均为0.9998.通过精密度试验考察,以峰高为响应信号,相对标准偏差RSD(n=12)为2.90%-3.77%;以峰面积为响应信号RSD(n=12)为1.05%-3.15%.加标浓度与样品浓度相当时,以峰高为响应信号,回收率94.69%~106.93%.研究表明,采取反相分离模式,易实现扑尔敏两异构体的分离.  相似文献   

9.
为了建立新型钙通道拮抗剂MN9201的高效液相色谱(HPLC)手性拆分方法,采用Daicel OJ-H手性固定相色谱分析柱(250 mm×4.6mm,5 μm),优化色谱条件,拆分MN9201消旋体.建立的HPLC手性拆分条件为:用Daicel OJ-H手性分析柱,以正己烷-异丙醇-三乙胺(91:9:0.1,V:V:V)为流动相,流速为0.5 mL/min,检测波长为237 nm,MN9201对映体可达到基线分离.本研究为MN9201单一对映异构体的分离、制备及含量测定等提供了简单、快捷的方法.  相似文献   

10.
HPCE法测定双黄连粉针剂中黄芩苷的质量浓度   总被引:2,自引:0,他引:2  
建立测定注射用双黄连(冻干)中黄芩苷含量的高效毛细管电泳法(HPCE).采用石英毛细管柱,硼酸和硼砂缓冲溶液pH值为8.71,室温25℃,分离电压25kV,检测波长274 nm,黄芩苷质量浓度在0.1~0.5 mg/mL的范围峰面积呈良好的线性关系,相关系数r为0.999 5.测定结果与高效液相色谱HPLC法测定结果一致.实验证实该法灵敏、快速、准确、环保,可作为注射用双黄连(冻干)质量控制方法.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

16.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

17.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

18.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

19.
Quality traits in wheat (Triticum aestirum L.) were studied by quantitative trait locus (QTL) analysis in a recombinant inbred line (RIL) population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross (ChSh). Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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