HPLC示差折光分析法测定D-氨基葡萄糖盐酸盐中的N-乙酰-D-氨基葡萄糖

利用高效液相示差折光分析法测定D-氨基葡萄糖盐酸盐中的N-乙酰-D-氨基葡萄糖.方法采用Alltech C18柱(250×4.6 mm,5 μm),流动相为乙腈-醋酸盐缓冲液(3∶97),流速1 mL/min,柱温40℃,进样量20 μL.N-乙酰-D-氨基葡萄糖在4.18～1 079.33 μg/mL范~围内星显著的线性关系,相关系数为0.999 3.方法的加标回收率98.78%,检出限4.18 μg/mL.     

高效液相色谱-核粒子计数检测氨基葡萄糖类化合物

核粒子计数检测器是基于水凝聚激光计数专利技术(WCPC),对低紫外吸收的化合物有较强的优势.建立了高效液相色谱-核粒子计数检测器(HPLC-NQAD)检测D-氨基葡萄糖盐酸盐和N-乙酰-D-氨基葡萄糖的方法.采用AsahipakNH2(250mm×4.6mm,5μm)色谱柱,V(乙腈)∶V(0.5%三乙胺水溶液)=75∶25为流动相,流速为0.8mL/min,进样量为10μL,10min内完成检测.在NQAD蒸发管温度55℃、气体压力200kPa条件下,D-氨基葡萄糖盐酸盐与N-乙酰-D-氨基葡萄糖之间的分离度2.32,前者的检出限为16ng,定量限为50ng,后者的检出限为8ng,定量限为24ng.D-氨基葡萄糖盐酸盐在10.03～2 005.20μg/mL范围内线性回归相关系数为0.999 5,N-乙酰-D-氨基葡萄糖在10.18～2 036.80μg/mL范围内线性回归相关系数为0.999 9.检测D-氨基葡萄糖盐酸盐和N-乙酰-D-氨基葡萄糖的精密度实验的相对标准偏差(RSD)分别为1.53%和1.38%,平均回收率分别为100.18%和101.02%.该方法用于D-氨基葡萄糖盐酸盐和N-乙酰-D-氨基葡萄糖的检测,可靠、快速、简便.     

澳洲茄胺盐酸盐的质量控制

研究以高效液相色谱法控制澳洲茄胺盐酸盐质量的方法. 色谱柱为Agilent ZORBAXEclipse XDB-C₁₈柱(150 mm×4.6 mm, 5 μm), 流动相为V_{甲醇∶V乙腈∶V0.020 mol·L^-1乙酸铵=60 ∶35 ∶5, 流速为1 mL/min, 检测波长为205 nm, 进样量为10 μL. 结果表明, 采用该方法 澳洲茄胺盐酸盐与其他杂质分离良好, 线性 范围5~500 μg/mL(r=0.999 3, 理论塔板数n＞12 000, R＞1.5), 加 样平均回收率为98.6%(n=9), 重现性试验相对标准偏差（RSD）为0.618%.}     

反相高效液相色谱法测定氨基葡萄糖硫酸盐

改进了对硫酸氨基葡萄糖检测的反相高效液相色谱方法.柱前用异硫氰酸苯酯(GITC)衍生,在254 nm紫外波长处紫外检测洗脱液.色谱柱使用C18柱,流动相是由MeOH/H2O/CH3COOH(体积比为20∶79.96∶0.04)组成,流速为0.6 mL/min.结果显示,在氨基葡萄糖含量为8～100 μg/mL范围内呈线性关系(r=0.998 5),样品平均回收率为98.72%,RRSD=0.473% (n=5) .该方法简便、准确,可用于氨基葡萄糖硫酸盐的检测.     

RP-HPLC直接测定水果中维生素C含量

应用反相高效液相色谱法对时令水果中维生素C含量进行直接测定.方法: 色谱柱Eclipse XDB-C18 (5 μm 4.6×250 mm);流动相乙腈-水(40∶ 60 v/v);流速1.0 mL/min;检测波长275 nm.实验结果表明维生素C在(10 ～ 640) μg/mL范围内呈良好线性,R2=0.999 96,回收率为99.3% ～ 104.5%,RSD=1.65%.本法操作简便,结果准确、重现性好,为测定水果中维生素C的含量提供了一种有效方法.     

高效液相色谱法测定人血浆中硫普罗宁的浓度

建立了以反相高效液相色谱法测定人血浆中硫普罗宁浓度的方法.采用Agilent C8 (250 mm×4.6 mm,5μm)色谱柱,乙腈:水(用磷酸调pH至2.5) =8:92(v/v),为流动相,检测波长203 nm,流速1.0 mL·min-1.硫普罗宁浓度在1.5～1 600 μg·mL-1浓度范围内,峰面积与浓度...     

硫酸软骨素片含盐酸氨基葡萄糖量的测定

建立硫酸软骨素片含盐酸氨基葡萄糖量测定方法.采用Hypersil C18柱(4.6mm×250mm,5μm),以0.68％醋酸钠缓冲溶液-甲醇(80∶20)为流动相,检测波长340nm.盐酸氨基葡萄糖在100～2 000μg/mL的质量浓度范围内呈良好的线性关系(r=0.999 9),平均回收率为103.2％(RSD=...     

HPLC-ELSD法测定盐酸氨基葡萄糖胶囊中盐酸氨基葡萄糖的含量

采用高效液相色谱-蒸发光散射检测法测定了盐酸氨基葡萄糖胶囊的含量.使用氨基色谱柱(250 mm×4.6 mm,5μm),流动相组成为乙腈:水=(7:3),流速为1.0 m L/min,在盐酸氨基葡萄糖检测含量浓度范围为0.2~1.2 mg/m L时与峰面积呈线性关系,R2为0.9999,平均加样回收率为99.86%,RSD为1.37%.该法简单,准确,无需衍生反应,精密度和重现性较好,是盐酸氨基葡萄糖胶囊含量测定的有效方法.     

HPLC法同时测定石韦药材中绿原酸、芒果苷和木犀草素的质量浓度

建立了一种反相高效液相色谱法,同时分离石韦药材中绿原酸、芒果苷和木犀草素,并测定其质量浓度.采用超声优化提取石韦的有效成分:Phenomenex Gemini 5 μm C18(150×4.6 mm,5 μm)色谱柱,甲醇-冰乙酸溶液为流动相,梯度洗脱,流速为0.8 mL/min;并用波长程序进行检测,柱温35℃,外标法定量.结果表明,绿原酸、芒果苷、木犀草素的线性范围分别为0.084～40.00,0.084～40.00,0.084～13.33 μg/mL(R＞0.999),平均回收率为96.3%～97.8%,相对标准偏差小于2.16%.     

水产品中氧氟沙星对映体拆分研究

采用CHIRALCEL OD-H(4.6 mm×250 mm,5.0 μm,Daicel)手性色谱柱拆分了氧氟沙星对映体,考察了流动相组成和流速等对手性分离的影响.确定了最佳的拆分条件:流动相为正己烷-乙醇(60:40,v/v),流速为0.6 mL/min,柱温为20℃,检测波长为294 nm.在此条件下氧氟沙星对映体的分离度为1.69.左氧氟沙星和右氧氟沙星的检出限分别为0.02 μg/g和0.03 μg/g,定量限分别为为0.04 μg/g和0.05 μg/g.左氧氟沙星平均回收率为83.46％,日间精密度和日内精密度的分别为0.34％和0.44％.右氧氟沙星平均回收率为87.32％.日间精密度和日内精密度分别为0.46％和0.69％.     

Markedness and its Interpretation in Language Use

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.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

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.     

低渗透非均质砂岩油藏启动压力梯度研究

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。     

On Tragic Consciousness In The Works By Ernest Hemingway

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.     

Design and analysis of generic LBS application developing platform

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.     

橡胶颗粒沥青混合料低温抗裂性试验研究

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.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-