逆流色谱仪固相保留机理的分析

为了提高高速逆流色谱仪的固相保留率,扩大逆流色谱仪的应用范围,本文通过结合物理、数学知识,分析固-液摩擦力、液-液摩擦力之间的相互影响,并通过数学模型验证了平面螺旋柱的切向离心力作用。此三种力共同决定了流动相的在柱内流速的改变,从而影响到柱内流动相的横截面积,继而影响到固定相的横截面积,最终决定了固相保留率的大小;并通过实验结果加以验证,得出F-H-U与R-H-U两种模式的固相保留效果最好。     

逆流色谱仪器装置的研究进展

逆流色谱是一种快速、高效、无固定相载体的新型液-液分配色谱技术.综述了高速逆流色谱、双向逆流色谱、正交轴逆流色谱、pH-区带精制逆流色谱及螺线型圆盘柱式逆流色谱仪器装置的研究进展,介绍了高速逆流色谱-质谱联用技术、高速逆流色谱.蒸发光散射联用技术、高速逆流色谱.高效液相色谱联用技术及二维逆流色谱技术的发展状况.     

α-磺酸脂肪酸聚乙二醇酯混合物的柱色谱分离

依据液固色谱的分离原理,在50 cm长、200～260目硅胶G柱上、常压下,对α-磺酸脂肪酸聚乙二醇酯混合物[1]进行液固色谱分析.通过改变样品混合物处理条件及流动相极性,得到分离产品.α-磺酸脂肪酸聚乙二醇(6000)单、双酯的收率分别为56%和21%.由红外光谱对组分结构进行认证.     

专利

一种逆流色谱法分离苦马豆素的方法公开号:CN103073544A公开日:2013.05.01申请人:中国科学院兰州化学物理研究所摘要本发明公开了一种逆流色谱法分离苦马豆素的方法。本发明以甲基叔丁基醚、正丁醇以及水混合后静置分层,构成逆流色谱固定相、流动相的溶剂体系;将固定相以较大流速泵入逆流色谱仪分离柱中;待柱中充满固定相后,开机,使     

气质联用法测定饮用水嗅味物质的前处理技术

系统研究和对比了用于气相色谱-质谱联机测定饮用水嗅味物质的液-液萃取、固相萃取、固相微萃取等样品前处理技术.结果显示,采用C18为柱填料、甲醇作为洗脱剂的固相萃取法效果最优,土臭素和2-甲基异莰醇两种嗅味物质测定结果的相对标准偏差分别为1.5%和1.7%,回收率分别为98.8%～102.0%和99.5%～104.0%.     

固相萃取-高效液相色谱法测定偶氮染料橙黄G的降解产物1-胺基-2-萘酚-6,8-二磺酸

提出了固相萃取-高效液相色谱法测定偶氮染料橙黄G的Fenton反应降解溶液中1-胺基-2-萘酚-6,8-二磺酸。用OnGuardⅡH固相萃取小柱去除降解液中的Fe2+,C18柱为分离柱,以乙腈-10mmol·L-1乙酸铵(20+80)溶液为流动相洗脱,检测波长为254nm。1-胺基-2-萘酚-6,8-二磺酸的线性范围为0.05~5.0mg·L-1,检出限(3S/N)为0.15mg·L-1。加标回收率在92.1%~99.2%之间,日内及日间相对标准偏差分别在2.8%~3.4%,4.1%~7.7%之间。     

2-(9-蒽基)-2-甲氧基乙酸乙酯的高效液相色谱手性拆分

以键合在5 μm硅胶上的纤维素-三(二甲基苯基氨基甲酸酯)为色谱柱的手性固定相,采用高效液相色谱(HPLC)法对外消旋的2-(9-蒽基)-2-甲氧基乙酸乙酯进行了手性拆分.对影响2-(9-蒽基)-2-甲氧基乙酸乙酯拆分的三个重要因素:流动相组成、流速、色谱柱温度进行了研究.实验结果表明,在流动相组成为正已烷-异丙醇(94/6,V/V),流速1.0 mL/min,柱温20℃的条件下,2-(9-蒽基)-2-甲氧基乙酸乙酯对映体得到很好的分离,分离度为3.63.     

液液萃取-气相色谱-质谱法测定墨水中的16种多环芳烃

采用液液萃取-气相色谱-质谱法测定墨水中的16种多环芳烃。样品经二氯甲烷液液萃取后,使用固相萃取技术进行纯化。在气相色谱分离中用DB-5MS色谱柱为固定相,在质谱分析中采用选择离子监测模式。16种多环芳烃在一定的质量浓度范围内与其峰面积呈线性关系,方法的检出限(3S/N)在5.0~30μg·kg-1之间。以空白样品为基体进行加标回收试验,所得回收率在60.6%~116%之间,测定值的相对标准偏差(n=6)在1.5%~5.3%之间。     

2-戊基-3-苯基-2,3-环氧丙醇对映体在手性柱上的拆分研究

采用多糖类手性固定相,建立2-戊基-3-苯基-2,3-环氧丙醇对映体的高效液相色谱(HPLC)手性分析方法。考察了手性柱类型、流动相组成、流速及柱温对2-戊基-3-苯基-2,3-环氧丙醇对映体拆分的影响。结果表明,以Chiralcel OD-H色谱柱(25×0.46cm,5μm)分离,采用正己烷-异丙醇(V/V,90∶10)作流动相,在流速为0.8 mL·min-1,柱温25℃,检测波长210nm的条件下,2-戊基-3-苯基-2,3-环氧丙醇对映体能达到基线分离,且具有较好的重复性和稳定性,可用于对映体的拆分及质量控制。该方法也适用于2-戊基-3-苯基-2,3-环氧丙醇类似物质的手性拆分。     

高速逆流色谱双水相体系分离蛋白质

利用多分离柱高速逆流色谱仪,研究了聚乙二醇1000(PEG1000)-磷酸盐双水相体系的固定相保留率及该体系对蛋白质混合物和鸡蛋清样品的分离。以14.0%PEG1000-16.0%磷酸盐体系的上相为固定相,在流速0.6 mL/min和转速900 r/min的条件下,固定相的保留率达到33.3%。在pH 9.2的PEG1000-磷酸盐双水相体系中,细胞色素C、溶菌酶和血红蛋白的分配系数差异最大,采用该pH值的14.0%PEG1000-16.0%磷酸钾盐双水相体系,在流速1.0 mL/min和转速850 r/min的条件下,成功地分离了这3种蛋白质的混合物。鸡蛋清中的主要蛋白质成分卵转铁蛋白、卵白蛋白和溶菌酶在pH 9.2的15.0%PEG1000-17.0%磷酸钾盐体系中也具有最大的分配系数差异。采用该体系,在流速1.0 mL/min和转速850 r/min的条件下,成功地分离了鸡蛋清样品,得到的卵白蛋白、溶菌酶和卵转铁蛋白的电泳纯度分别为100％,100％和60％,收率均大于90％。     

Electrowetting dynamics of microfluidic actuation

When voltage is suddenly applied to vertical, parallel dielectric-coated electrodes dipped into a liquid with finite conductivity, the liquid responds by rising up to reach a new hydrostatic equilibrium height. On the microfluidic scale, the dominating mechanism impeding this electromechanically induced actuation appears to be a dynamic friction force that is directly proportional to the velocity of the contact line moving along the solid surface. This mechanism has its origin in the molecular dynamics of the liquid coming into contact with the solid surface. A simple reduced-order model for the rising column of liquid is used to quantify the magnitude of this frictional effect by providing estimates for the contact line friction coefficient. Above some critical threshold of voltage, the electromechanical force is clamped, presumably by the same mechanism responsible for contact angle saturation and previously reported static height-of-rise limits. The important distinction for the dynamic case is that the onset of the saturation effect is delayed in time until the column has risen more than about halfway to its static equilibrium height.     

微囊藻毒素-LR免疫亲和层析柱的研制和应用

用CNBr-activated Sepharose4B和微囊藻毒素-LR的单克隆抗体制备了免疫亲和层析柱,测得抗体偶联率在75.7%~94.1%之间。制得的免疫亲和层析柱最大柱容量在76~95ng之间,柱空白为0,回收率在90.8%~105.1%之间。柱子再生重复使用6次后,回收率不低于75%。建立了免疫亲和层析柱-高效液相色谱测定水样中的微囊藻毒素-LR的方法。该法检出限为5ng/L;线性定量范围为10~500ng/L。实验结果显示,免疫亲和层析柱特异性好,一次净化能除去绝大部分干扰物,净化效果明显优于现有的固相萃取柱。     

A comparison of temperature and mobile phase composition effects for bonded liquid crystal and polymeric stationary phases in HPLC

Summary Using two polycyclyic aromatic hydrocarbons as solutes, a comparison is made between a bonded liquid crystal stationary phase and a conventional polymeric C-18 phase. The bonded nematic liquid crystal phase was the silanized form of 4-[4-(allyloxy)benzoyl-oxy]biphenyl and the polymeric phase was Vydac 201TP. Both phases display shape and planarity selectivity as indicated by the results of the variable temperature and mobile phase composition studies. The slot theory of retention can be used to explain these results. However, the liquid crystal phase is more sensitive to molecular geometry, probably due to its more ordered structure on the surface. Variable temperature experiments which compare retention during both heating and cooling provides additional support for this conclusion. With the polymeric bonded C-18 phase, each solute had identical retention at the same temperature during both the heating and cooling cycles. On the bonded liquid crystal phase, measurable differences in retention were observed at identical temperatures depending on whether the column was heated or cooled. This effect is attributed to a degree of partially reversible disordering which occurs as the column temperature was increased. However, conditioning with the appropriate mobile phase can restore the original retention characteristics of the bonded liquid crystal phase.     

反相高效液相色谱法同时分析三聚氰酸和三聚氰胺

建立了同时分析三聚氰酸和三聚氰胺的反相高效液相色谱法．发现三聚氰酸和三聚氰胺在C8柱上的保留比在C18柱上明显要强,这一结果表明三聚氰酸和三聚氰胺在反相固定相中的保留并非以通常的疏水分配作用为主导．方法的紫外检测下限为0．034～0．31mg／L,标准曲线线性范围为0．5-100mg／L．方法不经特殊的样品前处理即可用于奶粉和游泳池水等样品中三聚氰酸和三聚氰胺的同时分析．     

Dependence of the retention volumes of additional streaming current responses and of the column void volume on mobile phase composition

Summary The influence of the alcohol content of the mobile phase and water, acetic acid and aniline as mobile phase additives on the generation and shape of two additional changes of the streaming current, generated inside the liquid chromatography column by injection of any sample and recorded before the responses of retained solutes, was studied in a normal-phase system using silica gel as the stationary phase. The mobile phases were based on a n-heptane-1-propanol mixtures. Under the same conditions the relationships between the column interparticle volume, the column void volume and the total liquid volume in the column and the retention volumes of these two streaming current responses, having the form of chromatographic peaks, were studied. The column void volume was identified with the retention volume of n-octane. The total liquid volume in the column (column hold-up) was calculated from the weight loss of the column wetted with water at first and then dried in nitrogen stream. The retention volume of the first streaming current response equals the column interparticle volume disregarding the mobile phase composition. If the 95∶5 n-heptane-1-propanol mobile phase contains water up to 80% of its saturated concentration (up to 0.114% by vol.), the retention volume of the second response agrees with the total volume of the liquid in the silica gel column, with a precision better than 2%. At a higher relative water saturation the retention volume of the second response increases, while the column void volume decreases. Both changes are explained by the spontaneous formation of a highly polar stagnant liquid in the pores of the silica gel.     

新型程序涂渍色谱柱程序效应的研究

新型程序涂渍色谱柱程序效应的研究许鸿生，洪辉（湘潭大学化学系，湘潭，４１１１０５）关键词新型程序柱，程序效应，气相色谱关于程序涂渍色谱柱的问题，国内外研究指数函数程序柱的较多［１～３］，色谱柱涂渍结构改变后，组分的保留行为及柱效能都发生较大变化．作者...     

Analysis of triacylglycerols on porous graphitic carbon by high temperature liquid chromatography

The retention behaviour of several triacylglycerols (TAGs) and fats on Hypercarb, a porous graphitic carbon column (PGC), was investigated in liquid chromatography (LC) under isocratic elution mode with an evaporative light scattering detector (ELSD). Mixtures of chloroform/isopropanol were selected as mobile phase for a suitable retention time to study the influence of temperature. The retention was different between PGC and non-aqueous reversed phase liquid chromatography (NARP-LC) on octadecyl phase. The retention of TAGs was investigated in the interval 30-70 degrees C. Retention was greatly affected by temperature: it decreases as the column temperature increases. Selectivity of TAGs was also slightly influenced by the temperature. Moreover, this chromatographic method is compatible with a mass spectrometer (MS) detector by using atmospheric pressure chemical ionisation (APCI): same fingerprints of cocoa butter and shea butter were obtained with LC-ELSD and LC-APCI-MS. These preliminary results showed that the PGC column could be suitable to separate quickly triacylglycerols in high temperature conditions coupled with ELSD or MS detector.     

全自动固相萃取技术同时测定动物产品中9种磺胺药物残留

针对目前动物产品中兽药残留检测样品前处理繁琐的问题,应用全自动固相萃取技术对动物产品中9种磺胺类药物残留检测的样品前处理方法进行了系统的研究,对提取溶剂、固相萃取柱、淋洗液、洗脱溶剂及仪器分析条件进行了优化选择,建立了新型磺胺药物残留检测的全自动固相萃取净化方法.经不同检测单位验证,该方法的加标回收率为78.4%～107.8%,精密度为3.9%～11.0%检出限为0.010～0.020mg/kg,满足出口检测要求.     

Retention behavior of proteins in size-exclusion electrochromatography with a low-voltage electric field perpendicular to the liquid phase streamline

A novel preparative size-exclusion electrochromatography with an oscillatory low-voltage electric field perpendicular to the liquid phase streamline (pSEEC) was proposed with a column design of rectangular cross-section. The column of 12 cm length was packed with Sephadex G-75, and the retention behavior of bovine serum albumin (BSA) and myoglobin (Myo) was extensively investigated under various conditions. The results indicated that the partition coefficient of a charged protein increased significantly on increasing the current strength as well as the difference between its pI and pH. The partition coefficient also increased on decreasing the mobile phase conductivity. For the gel-excluded protein like BSA, the concentration polarization (CP) on the gel surface induced by the protein electromigration was the main reason for the increased retention. For a gel-permeable protein like Myo, both the CP and electrophoretic migration in the solid phase contributed to its increased retention. Further results exhibited that the polarization would be offset by diffusion, because the accumulated protein would flux back to the bulk liquid phase. Therefore, when the electrically induced mass flux was equal to the diffusion flux, the partition coefficient did not change with a further increase of the oscillatory current cycle. Finally, pSEEC was compared with SEC in the separation of protein mixtures of BSA/Myo as well as BSA/Myo/lysozyme. The results showed much better resolutions of the protein mixtures in pSEEC with the column as short as 12 cm. The potential of pSEEC for preparative protein separation was therefore demonstrated.     

Rapid and simultaneous determination of piperidinium and pyrrolidinium ionic liquid cations by ion pair chromatography coupled with direct conductivity detection

A method of ion-pair chromatography with direct conductivity detection was developed on a silicabased monolithic column for the fast and simultaneous determination of piperidinium and pyrrolidinium ionic liquid cations. The effects of the mobile phase, column temperature and flow rate on the retention of the cations were investigated. The retention rules were discussed. As an ion-pair reagent, sodium heptanesulfonate is more suitable than sodium pentanesulfonate for the separation and determination of piperidinium and pyrrolidinium cations. The increase of ion-pair reagent concentration led to the increased retention time of the cations. When acetonitrile content and mobile phase flow were increased, the retention time of the cations became shorter. The retention of piperidinium and pyrrolidinium cations is an exothermic process, and the retention of the cations conforms to the carbon number rule. The chromatographic analysis was performed using the Chromolith Speed ROD RP-18e column, 0.5 μmol/L sodium heptanesulfonate-5% acetonitrile as the mobile phase at a flow rate of 3.0 mL/min and column temperature of 30℃. Separation of N-methyl-N-ethyl piperidinium, N-methyl-N-propyl piperidinium, N-methyl-N-butyl piperidinium and N-methyl-N-ethyl pyrrolidinium, N-methyl-N-propyl pyrrolidinium, N-methyl-N-butyl pyrrolidinium cations were achieved within 10 min. The detection limits (S/N=3) were between 0.19 and 3.08 mg/L. Relative standard deviations (n=5) for peak areas were less than 1.2%. The method has been applied to the determination of piperidinium and pyrrolidinium cations in ionic liquid samples. The spiked recoveries of ionic liquid cations were between 96% and 111%. The method is accurate, reliable, rapid, and has a better practicability.