基于聚(2-甲基-2-■唑啉)和聚丙烯酸的混合刷在毛细管电泳在线富集溶菌酶中的应用

制备了一种对溶菌酶具有可控吸附性能的混合刷涂层毛细管,用于毛细管电泳在线富集溶菌酶以提高其检测灵敏度。首先,分别通过阳离子开环聚合和可逆加成-断裂链转移(RAFT)聚合合成聚(2-甲基-2-■唑啉)(PMOXA)和聚丙烯酸(PAA),然后将甲基丙烯酸缩水甘油酯(GMA)分别与PMOXA和PAA通过自由基共聚和RAFT聚合合成出聚(2-甲基-2-■唑啉)-r-甲基丙烯酸缩水甘油酯(PMOXA-r-GMA)和聚丙烯酸-b-聚甲基丙烯酸缩水甘油酯(PAA-b-PGMA)。将PMOXA-r-GMA和PAA-b-PGMA的混合溶液以一定比例加入到毛细管内,通过加热即可制备出基于PMOXA和PAA的混合刷涂层毛细管。X射线光电子能谱(XPS)对毛细管原材料的表面组成研究结果表明,当混合溶液质量浓度为20 g/L、PMOXA-r-GMA和PAA-b-PGMA质量比为1∶1时,所得涂层中羧基的含量随着PAA链长的增加而增加;异硫氰酸荧光素标记溶菌酶(FITC-溶菌酶)吸附实验结果显示,通过改变环境的pH和离子强度(I)可以调控涂层毛细管对溶菌酶的吸附和释放,在pH 7 (I=10~(-5) mol/L)条件下,毛细管可以吸附大量的溶菌酶,当条件变为pH 3 (I=10~(-1) mol/L)时,吸附的溶菌酶可以被释放出来。将这种具有溶菌酶可控吸附性能的涂层毛细管用于毛细管电泳在线富集溶菌酶,当PAA链长是PMOXA链长的2.2倍时,溶菌酶的灵敏度增强因子为17.69,检出限为8.7×10~(-5) g/L;同一天内对溶菌酶连续测定5次以及连续测定5天,峰面积的日内、日间相对标准偏差(RSD)分别为2.9%和4.1%,迁移时间的日内、日间RSD分别为0.9%和2.1%。涂层的制备只需一步,简单易行,而且涂层具有很好的稳定性。本研究为毛细管电泳分析痕量蛋白质提供了一种简单有效的方法。     

二维毛细管区带电泳/胶束电动毛细管色谱分离尿样中的药物及其对映体

建立了毛细管区带电泳(CZE)/胶束电动毛细管色谱(MEKC)二维毛细管电泳分离平台,CZE毛细管和MEKC毛细管通过一段带微孔的聚四氟乙烯(polytetrafluoroethylene, PTFE)套管固定。样品在CZE毛细管中分离后进入MEKC毛细管进一步分离,在二维转换过程中采用动态pH连接-胶束扫集法避免第一维分离区带在接口处扩散。将该方法成功用于鼠尿样品中4种药物及其对映体的分离,各组分的理论塔板数为(2.8～4.3)×104/m,检出限为0.015～0.052 mg/L,实际样品中峰面积和迁移时间的相对标准偏差(n=7)分别为1.7%～3.8%和1.3%～4.6%。方法重现性好、灵敏度和分离度高、峰容量大,适用于尿样中多种药物组分及其对映体的同时分离检测。     

杯芳烃涂层毛细管分离单胺类神经递质

本文设计制作了一种对烯丙基杯 [4 ]芳烃涂层毛细管。用于毛细管电泳分离的结果表明 ,此管能分离 5 羟色胺 ( 5 HT)、多巴胺 (DA)、去甲肾上腺素 (NE)、肾上腺素 (E)等结构相近的单胺类神经递质 ,而无涂层管则不能。本涂层管在pH4～ 9范围内的电渗较无涂层管下降约 75% ,且当pH <8时 ,电渗随pH的变化接近于线性关系 ,有利于高重现分离。杯芳烃涂层毛细管不降低紫外检测灵敏度。其主要问题是酚羟基对胺类仍有吸附 (或静电 )作用     

8-羟基喹啉动态有序介孔SiO_2涂层毛细管微萃取与ICP-MS在线联用分析天然水中铝的形态

本文采用溶胶-凝胶方法合成SiO_2溶胶,制备了8-羟基喹啉改性的有序介孔SiO_2涂层毛细管,建立了毛细管微萃取-电感耦合等离子体质谱(CME-ICP-MS)在线联用技术分析铝形态的新方法.选择游离态铝和Al-柠檬酸络合物为不同铝形态的代表物,详细探讨了不同实验参数对铝形态分离的影响.结果表明:8-羟基喹啉改性的有序介孔SiO_2涂层毛细管在pH为5.0～8.0的范围内可以有效地分离试样中的稳定态单核铝(柠檬酸铝)和非稳定态无机单核铝(游离态铝).方法的富集倍数为10,检出限为0.34 ng·mL~(-1).该法应用于湖水、池塘水和长江水中铝的组形态分析,所得结果与8-羟基喹啉负载硅胶微柱分离所得结果吻合很好.     

3,4-双取代氧化呋咱衍生物的合成、结构表征及热性能研究

以自制的偕氯肟基化合物为原料, 通过脱氯化氢、分子间二聚环化及硝化等反应合成了自行设计的8种目标化合物--3,4-二苯基氧化呋咱(1)、3,4-二(吡啶-2 -基)氧化呋咱(2)、3,4-二(吡啶-3 -基)氧化呋咱(3)、3,4-二(吡啶-4 -基)氧化呋咱(4)、3,4-二(吡嗪-2 -基)氧化呋咱(5)、3,4-二(4 -甲氧基苯-1 -基)氧化呋咱(6)、3,4-二(4 -氯苯-1 -基)氧化呋咱(7)及3,4-二(3 ,5 -二硝基苯-1 -基)氧化呋咱(8). 利用红外光谱、核磁共振、质谱、元素分析等手段对8种目标化合物进行了结构表征. 初步考察了不同取代基对二聚反应的影响, 发现取代基的吸电子能力越强, 越有利于形成氧化氰中间体结构, 目标产物收率越高|以化合物5为例, 探讨了反应温度、缚酸剂、缚酸剂浓度、反应介质等对二聚反应的影响, 确定适宜的反应条件为: 反应温度2～10 ℃, 缚酸剂选择3%～5%浓度的Na₂CO₃或KHCO₃, 反应介质为低沸点溶剂, 在此反应条件下, 化合物的收率分别为64.7%, 71.3%, 70.0%, 71.1%, 75.6%, 58.1%, 59.4%, 42.7%|利用差示扫描量热法(DSC)研究了目标化合物的热稳定性, 其中苯基取代衍生物的热稳定性较氮杂环衍生物好.     

大体积进样-逆电渗流堆积-毛细管区带电泳分离测定厚朴酚、绿原酸及咖啡酸

运用大体积进样-逆电渗流堆积-毛细管区带电泳分离测定了厚朴酚、绿原酸和咖啡酸。采用未涂层熔融石英毛细管(50 cm×50μm i.d.,有效柱长36 cm)分离;紫外检测波长为220 nm,运行缓冲液为40mmol/L四硼酸钠-20 mmol/L磷酸氢二钠(pH 9.0),分离电压16 kV,电动进样电压-12 kV,进样时间356s时达到最佳的分离效果。在优化条件下,上述3种化合物均在20 min内出峰,峰面积的RSD均小于4%。检出限分别为184.2、36.07、77.99 ng/L。将该法用于清肝利胆口服液中厚朴酚、绿原酸和咖啡酸的分离测定,结果满意。     

液相色谱-质谱法测定食品中甜蜜素

食品样品与水混合后超声振荡萃取使甜蜜素进入水溶液中,再用阴离子交换固相萃取柱净化.用乙酸(1 4)淋洗,所得流出液供液相色谱-质谱定量测定.峰高及甜蜜素的质量浓度在0.01～50.0 mg·L-1叫范围内呈线性关系,相关系数为0.999 8.其检出限(S/N=3:1)为20 pg,测得方法的回收率在94.1%～99.1%之间.     

二维毛细管电泳电化学检测尿样中的β-阻断剂

设计并制作了在柱电化学(EC)检测池,用于在同一根毛细管中进行中心切割二维毛细管电泳(2D-CE)在线纯化分离检测尿样中的6种β-阻断剂.尿样先在15 mmol/L NaAc缓冲液中进行毛细管区带电泳(CZE)分离,带正电荷的β-阻断剂与中性和带负电荷的干扰物质分成不同区带,然后在检测端施加13.8 kPa压力将干扰成分从毛细管入口端排出,同时将目标组分驱送到毛细管入口端,最后在90 mmol/L NaAc-30 mmol/L SDS缓冲液中进行胶束电动毛细管色谱(MEKC)分离.场放大样品堆积(FASS)/胶束推扫在柱双重富集技术不仅有效抵消压力驱送过程中产生的区带扩散,还可进一步压缩样品区带,提高检测灵敏度.本方法成功用于服药后鼠尿样品中6种β-阻断剂的分离测定,经第一维CZE分离排除干扰后,在未涂层毛细管柱(60 cm ×50 μm i.d.)、90 mmol/L NaAc/HAc-30 mmol/L SDS运行缓冲液、检测电位0.8 V、运行电压10 kV条件下,对6种β-阻断剂进行在线富集分离,峰高、峰面积和迁移时间的相对标准偏差(RSD)分别为2.0%～4.1%, 1.4%～3.7%和0.9%～2.7%(n=6).本研究为毛细管电泳在复杂样品在线纯化分析等方面的应用提供了新方法.     

固相萃取-高效液相色谱法测定水中酚同系物

水样中7种酚同系物用固相萃取法在Oasis HLB柱上预富集,经吹氮干燥后用1 mL甲醇将包括苯酚、4-硝基酚、3-甲基酚、2-氯酚、2,4-二氯酚、2,4,6-三氯酚及五氯酚在内的7种酚同系物从柱上淋洗,所得淋出液直接进样进行高效液相色谱法测定.在所提出的最佳测定条件下,4-硝基酚质量浓度在4.0 mg·L-1以内,其余6种酚同系物质量浓度在20.0 mg·L-1以内与相应的检测信号之间呈线性关系,以10倍信噪比计算方法的测定下限,测得4-硝基酚的测定下限为0.02 mg·L-1,其余6种酚同系物为0.1 mg·L-1以下.用标准加入法测定方法的回收率,所用基体水样中未检出上述7种酚同系物,测得回收率在79.4%-103.0%之间,相应的相对标准偏差(n=7)在1.0%～6.7%之间.     

固相萃取-高效液相色谱法测定羊肉中复方硝基酚钠残留量

羊肉样品经0.3mol·L-1氢氧化钠溶液提取,离心所得上清液过CEC18固相萃取柱净化。流出液用盐酸调整酸度pH至3.0±0.3后再过AccuBONDⅡODS-C18柱净化,依次用3%(体积分数)氨化甲醇1.00mL和水0.30mL洗脱,所得淋洗液供高效液相色谱分析。以AgilentZORBAX SB-C18色谱柱为分离柱,以甲醇-水(40+60)混合液为流动相进行洗脱,用紫外检测器于波长283nm处检测。3种硝基酚钠的质量浓度均在50～2 000μg·L-1范围内与峰面积呈线性关系。在125,500,1 000μg·L-1 3个添加水平下进行回收试验,硝基酚钠的回收率在74.5%～93.9%之间,相对标准偏差(n=5)小于6.5%。     

Adsorption of Human Serum Albumin onto PVA-coated Affinity Microporous PTFE Capillary

Affinity dye-ligand Cibacron Blue F3GA（CB F3GA） was covalently coupled with poly（vinyl alcohol）（PVA） coated on the inner surface of microporous poly（tetra-fluoroethylene）（MPTFE） membranous capillary. The PVA-coated PTFE capillary surface was characterized by XPS and FESEM. The grafting degree of PVA and the amount of CB F3GA immobilized onto the membranous capillary were 23.5 mg/g and 89.6 pmol/g, respectively. These dyed membranous capillaries were chemically and mechanically stable, and could be reproducibly prepared. Human serum albumin（HSA） was selected as model protein. The saturation adsorbance of the dye attached membranous capillary was 85.3 mg HSA/g, while the capacity of non-specific adsorption for HSA was less than 0.3 mg/g.     

Metal speciation using capillary electrophoresis--inductively coupled plasma atomic emission spectrometry and polytetrafluoroethylene capillaries

A capillary electrophoresis--inductively coupled plasma atomic-emission spectrometry (CE-ICP-AES) system using a polytetrafluoroethylene (PTFE) capillary has been developed. The CE-ICP interface was a modified concentric nebulizer. The PTFE capillary (50 microm internal diameter) was used as the central capillary of the nebulizer. Using the PTFE capillaries, the solution flow rate induced by the carrier gas flow was smaller than that of glass capillary. Solution flow was mainly induced by the CE electric field. Baseline separation of Ba2+/Mg2+ ion pair using simple buffer solution of 0.014 M sodium acetate was reported. Separation and correlation of metal species in metallothioneins (MT-1 and MT-2 in MT) of rabbit liver using the CE-ICP system were also discussed.     

Poly(tetrafluoroethylene) separation capillaries for capillary electrophoresis. Properties and applications

Poly(tetrafluoroethylene) (PTFE) is a material widely known for its inertness and excellent electrical properties. It is also transparent in the UV region and has a reasonable thermal conductivity. These properties make PTFE a suitable material for the separation capillary in capillary electrophoresis. Differences in the chemistry of the capillary wall compared to fused silica (FS) can make PTFE an interesting alternative to FS for some special applications. In this work, properties of a commercial PTFE capillary of approx. 100 microm i.d. were investigated, including the dependence of electroosmotic flow (EOF) on pH for unmodified and dynamically modified PTFE, optical properties, and practical aspects of use. The main problems encountered for the particular PTFE capillary used in this study were that it was mechanically too soft for routine usage and the crystallinity of the PTFE caused light scattering, leading to high background absorbance values in the low UV region. The profile of the EOF versus pH for bare PTFE surprisingly showed significantly negative EOF values at pH < 4.2, with an EOF of -30 x 10(-9) m2 V(-1) s(-1) being observed at pH 2.5. This is likely to be caused by either impurities or additives of basic character in the PTFE, so that after their protonation at acidic pH they establish a positive charge on the capillary wall and create a negative EOF. A stable cationic semi-permanent coating of poly(diallyldimethylammonium chloride) (PDDAC) could be established on the PTFE capillary and led to very similar magnitudes of EOF to those observed with FS. A hexadecanesulfonate coating produced a cathodic EOF of extremely high magnitude ranging between +90 and +110 x 10(-9) m2 s(-1) V(-1), which are values high enough to allow counter-EOF separation of high mobility inorganic anions. In addition, pH-independent micellar electrokinetic capillary chromatography (MEKC) separations could be easily realised due to hydrophobic adsorption of sodium dodecylsulfate (used to form the micelles) on the wall of the PTFE capillary. The use of polymers that would be mechanically more robust and optically transparent in the low-UV region should make such CE capillaries an interesting alternative to fused silica.     

高硅SAPO-34与聚四氟乙烯复合材料的合成

以二乙胺为结构导向剂, 在聚四氟乙烯乳液中水热法合成了高硅SAPO-34与聚四氟乙烯复合材料. XRD表明合成样品为SAPO-34结构, SEM照片表明型貌完好, 周围牢固地覆盖着聚四氟乙烯材料. 与不加聚四氟乙烯乳液合成样品相比, 添加后晶粒尺寸增大, 晶型更完好, 疏水和成膜性能提高.     

A polytetrafluoroethylene capillary viscometer

A polytetrafluoroethylene(PTFE) capillary Ubbelohde viscometer was designed and constructed. The relative viscosities of aqueous solutions of a polyethylene oxide and a polyvinylpyrrolidone sample were carefully determined down to an extremely dilute concentration region. In comparison with the data obtained from the common glass capillary viscometer, slippage is believed to occur in the PTFE capillary due to its hydrophobic nature. While for the glass capillary viscometer, conventional viscous flow is operative and adsorption phenomena occur since both the solvent water and aqueous solution are wet and/or adsorbed onto the glass capillary surface due to the existence of hydroxyl groups on glass surface. The data were analyzed with a recently developed wall-effect theory and satisfactory results were obtained.     

Effects of Tube Materials on Capillary Chromatography Based on Tube Radial Distribution of Ternary Mixture Carrier Solvents under Laminar Flow Conditions

A capillary chromatography system was developed using an open capillary tube and a ternary solvents carrier solution of water-hydrophilic/hydrophobic organic solvent mixture. The chromatography is called a tube radial distribution chromatography (TRDC) system. The TRDC system works without applying high voltages or using specific columns, such as monolithic and packed columns. In this study, the effects of tube materials on separation performance were examined in the TRDC system, by using poly(tetrafluoroethylene) (PTFE; 100–400?μm inner diameter), polyethylene (PE; 200?μm inner diameter), and copolymer of (tetrafluoroethylene–perfluoroalcoxyethylene) (PTFE–PFAE; 100?μm inner diameter) capillary tubes. An analyte solution of 2,6-naphthalenedisulfonic acid and 1-naphthol as a model was subjected to the system with a water–acetonitrile–ethyl acetate carrier solution; 15:3:2 volume ratio (water-rich carrier) and 3:8:4 volume ratio (organic solvent-rich carrier). The flow rates were adjusted to be 0.5?μL?min^?1 for PTFE and PTFE–PFAE tubes as well as 2.0?μL?min^?1 for PE tube under laminar flow conditions. These analytes in the solution were separated in this order with the water-rich carrier solution with baseline separation in the three capillary tubes, while they were eluted in the reverse order or not separated with the organic solvent-rich carrier solution. The effects of tube temperature on separation were also examined with the water-rich carrier solution; the best resolutions were observed at 0?°C of the tube temperature. The obtained results were compared with those of fused-silica capillary tube and discussed.     

Development of a capillary electrophoresis-mass spectrometry method using polymer capillaries for metabolomic analysis of yeast

Metabolomics is an emerging field in analytical biochemistry, and the development of such a method for comprehensive and quantitative analysis of organic acids, carbohydrates, and nucleotides is a necessity in the era of functional genomics. When a concentrated yeast extract was analyzed by CE-MS using a successive multiple ionic-polymer layer (SMIL)-coated capillary, the adsorption of the contaminants on the capillary wall caused severe problems such as no elution, band-broadening, and asymmetric peaks. Therefore, an analytical method for the analysis of anionic metabolites in yeast was developed by pressure-assisted CE using an inert polymer capillary made from poly(ether etherketone) (PEEK) and PTFE. We preferred to use the PEEK over the PTFE capillary in CE-MS due to the easy-to-use PEEK capillary and its high durability. The separation of anionic metabolites was successfully achieved with ammonium hydrogencarbonate/formate buffer (pH 6.0) as the electrolyte solution. The use of 2-propanol washing after every electrophoresis run not only eliminated wall-adsorption phenomena, but allowed for good repeatability to be obtained for migration times in the metabolomic analysis.     

Confinement of polyaniline chains in capillary layers: an ordering effect of the uniaxially aligned surfaces

An ordering effect of uniaxially aligned poly(tetrafluoroethylene) (PTFE) substrates prepared by rubbing on polyaniline (PANI) molecules at the interfaces of PTFE/PANI film and PTFE/PANI solution has been investigated using electronic absorption spectroscopy. It was observed slight dichroism in electronic spectra from only very thin (thickness approximately 20 nm and less) PANI films as well as from PANI solutions of capillary thickness (10 to 30 microm) confined by oriented PTFE surfaces. The ordering effect is discussed in terms of a hydrodynamic flow arising upon sample formation and steric factors at the PTFE surface, which cause uniaxial deformation of the polymer coil on the rubbed PTFE surface.     

Measurement of the surface tension of liquid marbles

The capillary rise and Wilhelmy plate methods have been used to study the "surface tension" of water marbles encapsulated with polytetrafluoroethylene (PTFE) powders of 1-, 35-, and 100-μm particle size. With the capillary rise technique, a glass capillary tube was inserted into a water marble to measure the capillary rise of the water. The Laplace pressure exerted by the water marble was directly measured by comparing the heights of the capillary rise from the marble and from a flat water surface in a beaker. An equation based on Marmur's model was proposed to calculate the water marble surface tension. This method does not require the water contact angle with the supporting solid surface to be considered; it is therefore a simple but efficient method for determining liquid marble surface tension. The Wilhelmy method was used to measure the surface tension of a flat water surface covered by PTFE powder. This method offers a new angle for investigating liquid marble shell properties. A discussion on the nature and the realistic magnitude of liquid marble surface tension is offered.