HPLC and HPCE analysis of microcystins RR, LR and YR present in cyanobacteria and water by using immunoaffinity extraction

Microcystins, which have their origin in species of cyanobacteria present in freshwaters, have recently been found to be important contaminants of the aquatic environment at trace levels. HPLC and HPCE with UV detection have been applied in the determination of such toxic compounds. Immunoaffinity chromatography for the selective extraction and clean-up of microcystins has been successfully applied to different matrices. Simple protocols for unambiguous determination of these toxins are presented and the immunoaffinity clean-up is compared with conventionally used solid phase extraction procedures. The development and optimisation of an on-line preconcentration procedure based on field amplified sample stacking for the analysis of microcystins by HPCE in the micellar electrokinetic chromatography mode is also described, using borate buffer with the anionic surfactant SDS, as separation electrolyte. Results indicate that sub-nanogram/gram content of microcystins can be detected in water samples, while sub-microgram/gram concentrations can be determined in algae samples.     

食品中金属离子的微波消解-高效毛细管电泳法测定

采用微波消解－高效毛细管电泳法测定食品中的K，Na,Ca,Mg等金属离子，考察了微波消解的最佳条件；研究了背景电解质，缓冲液pH值，操作温度和分离电压等对电泳分离中运行电流，电渗迁移率，峰形等参数的影响，确定了金属离子电泳分离的最佳实验条件；该法已应用于食品中金属离子的测定，并与原子吸收法进行比较，得到满意的结果。     

High performance separations of nucleic acids using capillary electrophoresis and high-performance liquid chromatography

High resolution separations of nucleic acids have been performed using high performance capillary electrophoresis (HPCE) and high performance liquid chromatography (HPLC). Electropherograms showing HPCE separations of single and double stranded DNA are presented and compared with HPLC separations. Single base resolution of poly(dA) oligonucleotides in the size range of 12 to 60-mers was achieved in 35 min using HPCE. Plate numbers for HPCE are in the hundreds of thousands and reproducibility is about 1–2 % (RSD). In comparison with HPLC separations, the resolution of nucleic acids obtained using HPCE is much better than that using HPLC, while reproducibility of HPCE is comparable with that of HPLC.     

毛细管电泳-迎头分析法测定血清或血浆中氯氮平的游离浓度

采用毛细管电泳-迎头分析模式体外实验测定了人血清白蛋白溶液、人血浆、兔血清和血浆样品溶液中游离氯氮平的浓度．根据前沿峰的峰高直接测定了样品溶液中的游离氯氮平浓度,并与传统超滤法进行了比较．通过考察施加的电压和运行缓冲液的组成对氯氮平电泳峰平台形成的影响确定了最优分离条件．讨论了氯氮平蛋白结合作用的选择性．     

分子印迹固相萃取-高效毛细管电泳法检测鸡肉中的恩诺沙星残留

以恩诺沙星为模板分子,α-甲基丙烯酸为功能单体,二甲基丙烯酸乙二醇酯为交联剂,制备了恩诺沙星分子印迹聚合物。以该分子印迹聚合物为固相萃取材料,采用高效毛细管电泳分离方式,建立了分子印迹固相萃取-高效毛细管电泳检测鸡肉中恩诺沙星的方法。结果表明,该方法能有效地萃取和检测鸡肉中的恩诺沙星。在优化条件下,恩诺沙星的检出限为92.02 μg/kg,定量限为336.04 μg/kg;不同恩诺沙星添加水平下的回收率为77.84%～86.52%,相对标准偏差为2.18%～3.76%。该方法适用于鸡肉中恩诺沙星残留的测定。     

不同产地金银花药材的HPCE指纹图谱分析

以40mmoL/L硼砂溶液为缓冲液,利用高效毛细管电泳(HPCE)法,建立不同产地金银花的HPCE指纹图谱并测定其中绿原酸的含量。工作电压为17kV,温度为25℃,压力进样时间为6s。不同产地金银花药材中绿原酸的含量为3.2%4.4%。通过对HPCE指纹图谱共有峰数据进行判别分析和聚类分析,可以将不同产地的金银花进行判别分类。HPCE指纹图谱可以用于较全面地考察金银花药材的质量。     

高效毛细管电泳浊度法检测牛奶及奶粉中的三聚氰胺

建立高效毛细管电泳(HPCE)浊度法检测牛奶和奶粉中三聚氰胺的方法。样品中加入三氯乙酸水溶液,加热样品至沸腾后自然冷却,使蛋白质充分凝聚、沉降,并提取三聚氰胺。色谱条件为:毛细管柱长度50cm、内径75μm,分离电压13kV,进样量12.3kPa×3s,分离温度25℃,检测波长236nm。加标回收率为83%～98%之间,定量限为1mg/kg。测量结果的相对标准偏差为1.8%～3.4%(n=5)。该法可用于大量牛奶和奶粉样品中三聚氰胺的快速检测。     

A block copolymer covalent coating acting as surfactants in separation of 2-[hydroxy(4-nitrophenyl)methyl]-cyclopent-2-enone and 4-nitrobenzaldehyde by capillary electrophoresis

An innovative block copolymer capillary coating P(MAn-alt-St)₁₂₇-b-PSt₅₉₂, synthesized by maleic anhydride and styrene, was developed as a new kind of coating for capillary electrophoresis. The covalent bond coating was effectively applied in the separation of raw material (4-nitrobenzaldehyde) and production (2-[hydroxy(4-nitrophenyl)methyl]-cyclopent-2-enone) in a Baylis-Hillman reaction using ammonium acetate with 20% tetrahydrofuran (v/v) as the buffer solution. Electroosmotic flow measurement gave an instantly stable value after 70 times continued injection in 5 days and showed that P(MAn-alt-St)₁₂₇-b-PSt₅₉₂ coatings could suppress electroosmotic flow effectively compared with the bare capillary. The effects of tetrahydrofuran and the pH of buffer on the separation were investigated. The characteristics of the coatings to form micelles similar to surfactants were detected by atomic force microscopy. Moreover, the superiority of this coating was further applied in the separation of four aromatic amines.     

Correlation between Molecular Structures and Relative Electrophoretic Mobility in Capillary Electrophoresis:Alkylpyridines

Introduction　　Highperformancecapillaryelectrophoresis (HPCE)hasnowbeenwidelyusedtoseparateanddetermineana lytesfromsmallinorganicandorganicionstomacromolec ularspeciessuchasDNAandproteins .Overthepastfewyears ,therehavebeenconsiderableinterestsinthedevel opingmethodsusingcapillaryelectrophoresistoseparatesmallorganicmolecules ,asacomplementarymethodtoHPLCseparations .1 3Electrophoreticmobility (μ)isthemostimportantparametergoverningtheseparationofso lutesincapillaryzoneelectrophoresis (…