毛细管电泳高频电导法测定粉防己药材中的生物碱

建立了千金藤属植物粉防己中生物碱测定的毛细管电泳高频电导法,以融硅毛细管(150μm×60cm)为分离柱,1mmol LHAc 2mmol LNH4Ac 10mmol Lβ CD 2mmol LSDS缓冲液为电泳介质,分离电压14.0kV,用高频电导法检测,粉防己药材中粉防己碱和去甲粉防己碱可实现定量分离和检测。探讨了缓冲液的种类、浓度、添加剂、分离电压和进样量对分离和检测的影响;在优化条件下的线性范围分别为:粉防己碱12 5～900μg mL,去甲粉防己碱25 0～900μg mL;检出限分别为:粉防己碱6 25μg mL,去甲粉防己碱12.5μg mL;样品加标回收率分别为92.7%～98.9%和95.9%～101%。     

反向毛细管电泳高频电导法测定牛黄中的胆酸

建立了毛细管电泳高频电导法快速简便测定牛黄粉中胆酸的新方法.考察了电泳介质的种类、浓度、 pH值以及操作电压和进样时间对分离检测的影响.缓冲液为0.5 mmol/L Na3PO4 2 mmol/L Na2HPO4 0.2 mmol/L CTAB(pH 11.7), 分离电压为 -15 kV时可实现较好的分离和检测.胆酸的线性范围为75～200 μg/mL, 检出限为0.1 μg/mL.线性方程为y=0.6054ρ-4.14991, r=0.953.回收率为100.9%, RSD(n=5)=2.1%.     

毛细管电泳高频电导法测定虫草中的有效成份

建立了毛细管电泳高频电导法同时测定腺苷和虫草素的方法。实验对电泳介质的种类、浓度以及操作电压和进样时间等因素进行了优化,在4mmol／L乳酸＋10％异丙醇＋80μg／mL羟甲基纤维素钠（pH=4．0）,分离电压20．OkV的条下测定了天然虫草和人工虫草菌丝制品中的腺苷和虫草素的含量,线性范围分别为2．0μg／mL～120μg／mL和3．0μg／mL～110μg／mL,检出限分别为0．5μg／mL和1．0μg／mL。     

高效毛细管电泳电导法快速检测复方维生素B片中的VB1、VB12、VB6和VC

采用高效毛细管电泳电导法同时分离、测定了复方维生素B片中的主要成分VB1, VB12,VB6和VC的含量.研究了运行缓冲溶液的酸度和浓度、电泳电压、进样时间等因素对电泳的影响.在优化的实验条件下40 mmol/L Tris -4 mmol/L H3BO3 (pH 8.0) 的缓冲溶液中加入0.30 mmol/L CTAB(溴化十六烷基三甲基铵),分离电压为15 kV,上述4组分在5 min内得到良好的分离.维生素B1,B12,B6和VC的线性范围分别为5.5～1.0 mg/mL; 15～1.5 mg/mL; 1.0～0.40 mg/mL和6.6～0.80 mg/mL; 检测限分别为0.80 μg/mL, 4.0 μg/mL, 0.50 μg/mL, 2.9 μg/mL; 5次测定峰高的相对标准偏差分别为2.2%, 1.6%, 3.9%, 2.8%.5次测定的平均回收率分别为99%, 94%, 100%, 97%.     

山豆根中苦参碱和氧化苦参碱的胶束毛细管电泳法测定

用胶束毛细管电泳法（MECC）测定山豆根中的苦参碱及氧化苦参碱的含量，以盐酸麻黄碱作内标物，20mmol/L硼砂缓冲溶液（含30mmol/L十二烷基硫酸纳，体积分数40％甲醇）作电解质（pH=9.35），于208nm紫外检测，山豆根提取液中有效成分都获得基线分离；定量分析表明，苦参碱的质量浓度在0．08－0．52g/L、氧化苦参碱质量浓度在0．03－0．44g/L其峰面积与质量浓度呈线性关系（r分别为0．9987和0．9976）；此外，还讨论了不同缓冲液浓度、十二烷基硫酸钠（SDS）浓度及甲醇含量对2种有效成分迁移行为的影响。     

司帕沙星的毛细管电泳高频电导法测定

采用毛细管电泳高频电导法检测了司帕沙星。探讨了缓冲液的种类、浓度、添加剂以及操作电压和进样时间等因素对分离的影响。选择3.0mmol LHAc-5.0?H5OH(V V)为电泳介质,分离电压20.0kV,在4min内可实现司帕沙星的分离检测。在优化条件下,司帕沙星的线性范围为6 0～280 0μg mL,检出限为1 9μg mL。在该条件下,片剂中的敷料不干扰测定,可成功测定片剂中的司帕沙星,样品回收率为98.7%～101%。     

毛细管电泳高频电导法测定尿中MDMA及其代谢物

建立了尿样中MDMA及其代谢物MDA的毛细管电泳高频电导法检测分析方法。对电泳分离缓冲介质的种类、浓度、pH值以及分离操作电压和进样时间等实验条件进行了优化。缓冲液为2．5mmol／L NH4 Ac 0．5mmol／L HAc 2mmol／L SDS 10mmol／L β-CD,分离电压为15kV时,可实现较好的分离与检测。该法在2．5～80μg/mL范围内。MDMA和MDA线性相关系数r分别为0．998和0．999,检出限均为1．0μg/mL(S／N=3)。不同添加浓度水平尿样,日间和日内RSD均小于5％,回收率均在90％以上,适于法医毒物分析和临床药物监测的需要。     

牡丹皮中有效成分丹皮酚的毛细管电泳快速检测新方法

采用毛细管电泳高频电导法对丹皮酚进行了快速分离检测。对电泳介质的种类及浓度、操作电压和进样时间等影响因素进行了优化。最佳条件为：分离介质1．0mmol／LH3BO3-3．0mmol／L三乙胺-10％CH,OH（pH=8．0）,分离电压20．0kV,25．0cm位差虹吸进样8．0s。在该条件下。可在4min内实现对丹皮酚的分离检测。线性范围为2．0～105μg／mL,检出限为0．3μg／mL。成功测定了中药牡丹皮中的丹皮酚,回收率达94％～99％。方法简便、快速、灵敏,可用于药物分析。     

微流控芯片非接触电导法快速测定盐酸美金刚片中盐酸美金刚的含量

建立了微流控芯片非接触电导法快速测定盐酸美金刚片中盐酸美金刚含量的方法。探讨了缓冲溶液的种类、浓度、pH值、进样时间及分离电压等因素对分离检测的影响。优化得到缓冲体系为含2%(体积分数)二甲基亚砜(DMSO)的3.0 mmol/L三乙胺-2.0 mmol/L磷酸缓冲溶液(pH 3.3),进样时间为10 s,分离电压为2.0 kV。优化条件下,盐酸美金刚的线性范围为10～2 000μg/mL(r~2=0.999 1);检出限为7μg/mL,定量下限为10μg/mL;精密度、稳定性、重复性实验的相对标准偏差(RSD)均小于2.0%;平均加标回收率为96.5%～99.2%;盐酸美金刚的检测时间小于18 s。该方法快速简便,适用于盐酸美金刚片中盐酸美金刚含量的测定。     

液相微萃取/后萃取-高效液相色谱法测定氧化苦参碱和苦参碱

建立了液相微萃取/后萃取-高效液相色谱法测定中药苦参、复方苦参注射液中氧化苦参碱和苦参碱含量的方法。利用自制的微萃取装置,选择异丙醇为萃取有机溶剂,2.00 mL NaOH(pH9)为供相,HCl(pH4)为接受相,聚丙烯腈纤维的长度为10 cm,搅拌速度为1500 r/min,萃取时间为30 min。萃取完成后,经高效液相色谱仪分析,测得氧化苦参碱和苦参碱线性范围分别为11~437 mg/L和10~433 mg/L;检出限均为1.0mg/L;相对标准偏差分别小于9.4%和6.7%。复方苦参注射液中氧化苦参碱和苦参碱的平均回收率分别为83.0%~116.1%和108.8%~117.8%;苦参药材中氧化苦参碱的平均回收率为104.3%~114.7%。本方法有机溶剂用量少,可有效去除复杂机体的干扰,测得结果满意。     

Capacitively coupled contactless conductivity detection with dual top–bottom cell configuration for microchip electrophoresis

An optimized capacitively coupled contactless conductivity detector for microchip electophoresis is presented. The detector consists of a pair of top–bottom excitation electrodes and a pair of pickup electrodes disposed onto a very thin plastic microfluidic chip. The detection cell formed by the electrodes is completely encased and shielded in a metal housing. These approaches allow for the enhancement of signal coupling and extraction from the detection cell that result in an improved signal‐to‐noise‐ratio and detection sensitivity. The improved detector performance is illustrated by the electrophoretic separation of six cations (NH, K⁺, Ca²⁺, Na⁺, Mg²⁺, Li⁺) with a detection limit of approximately 0.3 μM and the analysis of the anions (Br^?, Cl^?, NO, NO, SO, F^?) with a detection limit of about 0.15 μM. These LODs are significantly improved compared with previous reports using the conventional top–top electrode geometry. The developed system was applied to the analysis of ions in bottled drinking water samples.     

毛细管电泳及芯片毛细管电泳的电容耦合非接触电导检测

综述了毛细管电泳(CE)及芯片毛细管电泳(MCE)的电容耦合非接触电导检测(Capacitively Coupled Contactless Conductivity detection,C4D)的研究状况;并分别对其装置、检测的影响因素及其应用进行了评述。引用文献81篇。     

毛细管电泳法快速测定琥乙红霉素的含量

建立了毛细管电泳高频电导法测定琥乙红霉素的方法。探讨了缓冲溶液、有机溶剂添加剂以及分离电压和进样条件等因素对分离检测的影响。在电泳介质为2.0mmol/L柠檬酸-20.0?H5OH,分离电压20.0kV的优化条件下,在7min内即可实现琥乙红霉素的分离检测,线性范围为3.0μg/mL-150.0μg/mL,检出限为1.0μg/mL。方法简便、快速,可检测制剂中琥乙红霉素的含量。     

Advances in amperometric and conductometric detection in capillary and chip-based electrophoresis

Amperometric and conductometric detection are currently the two major electrochemical detection modes in capillary and chip electrophoresis. The ease of miniaturization and integration of electrochemical detection elements offers a high potential for the development of portable analytical devices based on electromigrative separations. The challenges and basic concepts of both detection principles in the context of capillary/chip electrophoresis are shortly introduced and milestones of the methodical developments are summarized from a historical perspective. Recent advances and applications are discussed with more detail. Particular attention is paid to new trends in this area of research such as measurements in short capillaries and the enormous progress and increased popularity of contactless conductivity detection. Correspondence: Frank-Michael Matysik, Institute of Analytical Chemistry, University of Leipzig, Linnéstr. 3, D-04103 Leipzig, Germany     

毛细管电泳高频电导法快速分离检测混合氨基酸

氨基酸(Am ino acids,AA s)是组成生物大分子的基本单元,与人的健康状况有极其密切的关系.在医学和生命科学研究中,微量氨基酸的分离检测具有重要意义.     

微流控芯片差示式非接触电导检测器的研制

研制了一种适合普通厚度盖片的分析芯片的差示式非接触电导检测器。在芯片上制作分离通道和参比通道,并在独立的电极板上对应于两通道末端位置设置两对电极,分析芯片置于电极板上。信号发生器产生的高频信号分成两路,分别加至分离通道和参比通道对应的激发电极,两通道对应的接收电极的微弱信号经差示放大和整流。当组分经过分离通道电极间区域时,电导率与参比通道出现差异,获得检测信号。实验考察了激发频率、激发电压、电极间距等对检测性能的影响。在优化检测条件下,即检测频率100 kHz、检测电压10 V(Vp-p)、电极间距0.9 mm时,对K+的检出限达12μmol·L-1,相对标准偏差为1.1%,并成功用于Na+、K+离子的分离检测。该检测器适用于容易制作的普通厚度盖片的分析芯片的检测,且芯片与电极板相互独立,使用方便。     

A thin cover glass chip for contactless conductivity detection in microchip capillary electrophoresis

A microfabricated thin glass chip for contactless conductivity detection in chip capillary electrophoresis is presented in this contribution. Injection and separation channels were photolithographed and chemically etched on the surface of substrate glass, which was bonded with a thin cover glass (100 μm) to construct a new microchip. The chip was placed over an independent contactless electrode plate. Owing to the thinness between channel and electrodes, comparatively low excitation voltage (20–110 V in V_p–p) and frequency (40–65 kHz) were suitable, and favorable signal could be obtained. This microchip capillary electrophoresis device was used in separation and detection of inorganic ions, amino acids and alkaloids in amoorcorn tree bark and golden thread in different buffer solutions. The detection limit of potassium ion was down to 10 μmol/L. The advantages of this microchip system exist in the relative independence between the microchip and the detection electrodes. It is convenient to the replacement of chip and other operations. Detection in different position of the channel would also be available.