微乳电动色谱-激光诱导荧光检测法快速分离测定麻黄碱和伪麻黄碱

以5-(4,6-三氯-s-三嗪基-2-氨基)荧光素为衍生试剂,建立了一种微乳电动色谱-激光诱导荧光检测法分析麻黄碱和伪麻黄碱的新方法。经过实验条件的优化,使用50mmol/L硼砂,5%微乳液(V/V)(微乳液组成(W/W)3.24%正己烷,3.24%SDS,26.44%正丁醇,57.08%水),14%乙腈(V/V)作为运行缓冲溶液,电压22.5kV,温度为25℃条件下,11min内可实现基线分离。分析物的峰高与浓度(2.5~75μg/L)之间存在较好的线性关系,相关系数为0.9915(麻黄碱)和0.9981(伪麻黄碱);检出限分别为2.39×10-3和3.85×10-3μg/L。将该法成功用于麻黄及其制剂中两种生物碱的分析,回收率在92.0%~108.4%之间。     

芯片毛细管电泳激光诱导荧光快速分离检测麻黄碱类兴奋剂

研究用芯片毛细管电泳激光诱导荧光检测系统分离测定经7-chloro-4-n itrobenzo-2-oax-1,3-d iazole(NBD-C l)衍生的麻黄碱和伪麻黄碱的实验条件。采用胶束毛细管电动色谱分离体系(12 mmol/L SDS 10mmol/L硼砂缓冲液,pH 9.0),在45 mm长的通道上实现了麻黄碱和伪麻黄碱的快速分离,一次分离小于1.5m in。10~100 mg/L范围内,峰高与浓度呈良好的线性关系,麻黄碱、伪麻黄碱的检出限分别是0.83 mg/L和1.10 mg/L。所建立的方法应用于尿中麻黄碱和伪麻黄碱的分离测定,取得满意的结果。     

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%.     

阳离子选择性耗尽进样-胶束扫集法测定尿液中的麻黄碱和可待因

联用选择性耗尽进样和胶束扫集两种在线富集技术,建立了尿样中麻黄碱和可待因含量测定的灵敏方法,并通过日内、日间、柱间实验考察了方法的稳定性.胶束扫集电动色谱缓冲体系为80 mmol/L 十二烷基磺酸钠(SDS)-20 mmol/L NaH2PO4(pH 2.20)-18%乙腈(V/V),分离电压-20 kV,进样电压10 kV,进样时间150 s,测量波长200 nm.同时讨论了pH值、SDS浓度、选择性耗尽进样萃取液电导、进样电压、进样时间和进水长度等对分离效果的影响.结果显示,方法富集功能很强,对麻黄碱和可待因含的富集倍数分别达5800和2490以上.在优化条件下,方法线性关系良好(r=0.9999),麻黄碱和可待因的线性范围分别为0.500～16.0 μg/L和2.00～48.0 μg/L,检出限分别为0.10和0.80 μg/L.方法稳定性良好,日内、日间和柱间的RSD分别为2.6%,5.9%和6.6%.应用于实际尿样分析,回收率在96.8%～106%之间,RSD≤4.7%,结果比较满意.     

小型黄曲霉毒素检测仪的研制

针对当前黄曲霉毒素检测方法中,中低端仪器无法实现多组分定量分析,高端仪器因价格高、体积大而无法在小型实验室推广的现状,开展了黄曲霉毒素专用检测仪的研制工作。设计并搭建了基于胶束电动色谱-发光二极管诱导荧光检测系统的仪器架构,对关键光学元件等进行了组合选择,以紫外发光二极管为光源,BP 365和BP 430分别为光源和荧光滤光片,多模石英光纤传导荧光信号,光电倍增管检测信号,并对胶束电动分离系统的缓冲溶液成分等进行了优化,实现了常见6种黄曲霉毒素的基线分离。在0.1~10μg/L浓度范围内,标准溶液的浓度与荧光响应的峰面积之间呈较好的线性关系,相关系数(r)均大于0.99;峰面积的日内相对标准偏差(RSD)为2.0%~2.4%,日间RSD为5.1%~6.0%。对6种黄曲霉毒素的检出限为0.3~0.8μg/kg,加标回收率为85.3%~97.0%。该仪器具有体积小、造价低、无需衍生化反应及大量有机试剂等特点,适用于食品中多种黄曲霉毒素的同时定量检测。     

Separation and Determination of Ephedrine, Pseudoephedrine and Methylephedrine by Capillary Electrophoresis with Electrochemiluminescence Detection

以PB - Eu化学修饰电极为工作电极,对乙烯基苄基三乙基氯化铵离子液体为拆分添加剂,首次米用毛细管电泳-电致化学发光法对麻黄碱、伪麻黄碱和甲基麻黄碱进行了分离和检测.考察了检测电位、分离缓冲液的种类和酸度、添加剂用量等条件对电泳分离效果及检测灵敏度的影响.在优化条件下,3种混合药物可在8 min内达到基线分离,甲基麻黄碱、麻黄碱和伪麻黄碱的质量浓度分别在0.025～10、0.025～25、0.05～10mg/L范围内与其峰面积呈良好但斜率略不同的两区段型线性关系,总的线性响应范围可达3个数量级.以质量浓度均为1.00 mg/L的3种混合药物合成样品进行6次平行测试,其峰面积和迁移时间的RSD分别小于4.5％和0.95％.该方法成功用于商品麻黄碱类药物制剂及中药麻黄原药中3种生物碱含量的测定,加标回收率为101％～111％.     

毛细管电泳电化学检测法测定马钱子中的士的宁和马钱子碱

用毛细管电泳电化学检测法测定了马钱子中的士的宁和马钱子碱.以BR缓冲溶液(35 mmol/L混酸用180 mmol/L NaOH调节至pH 6.50)为电泳液,分离电压为6 kV,检测电位为0.95 V,士的宁和马钱子碱在30 min内得到了良好分离.士的宁和马钱子碱浓度分别在0.35～35.00 μg/mL和0.40(40.00 μg/mL内具有良好的线性关系,检测限分别为0.08μg/mL和0.15μg/mL.应用于马钱子样品的测定.     

基于中空纤维液相微萃取的麻黄碱和伪麻黄碱优势构象的确定及含量测定

利用中空纤维液相微萃取方法(HF-LPME)分析麻黄碱和伪麻黄碱在不同基质中的优势构象,阐明了麻黄碱和伪麻黄碱的萃取机理;结合高效液相色谱(HPLC)建立了微量麻黄碱和伪麻黄碱的分离测定方法。以聚偏氟乙烯中空纤维为有机溶剂载体,正己醇为萃取溶剂,麻黄碱和伪麻黄碱的NaOH(5 mol/L)溶液为样品相,0.01 mol/L H2SO4溶液为接收相,在1200 r/min转速下萃取35 min,收集萃取液直接进行HPLC分析。麻黄碱和伪麻黄碱在水溶液中的线性范围为5～100 μg/L,检出限分别为1.9 μg/L和1.2 μg/L,富集倍数分别为38和61倍,平均回收率分别为100.6%±1.2%和103.2%±3.5%;在鼠尿液中的线性范围为100～5×104 μg/L,检出限分别为30 μg/L和42 μg/L,富集倍数分别为20和17倍,平均回收率分别为108.4%±4.4%和106.1%±5.4%。研究表明该方法操作简单,选择性高,适用于微量麻黄碱的含量测定和分析。     

毛细管电泳法快速测定五倍子中的没食子酸

建立了毛细管电泳高频电导法测定没食子酸的方法.探讨了缓冲溶液、有机溶剂添加剂、分离电压等因素对分离检测的影响.在电泳介质为10.0mmol/L Tris-5.0 mmol/L H3BO3-15.0?H5OH,分离电压22.0 kV的优化条件下,5.5 min内即可实现没食子酸的分析,线性范围为3.00～100 μg/mL,检出限为1.0 μg/mL.成功地检测了五倍子中的没食子酸.     

高效液相色谱法测定麻黄浸膏粉中麻黄类生物碱

采用高效液相色谱法分离了麻黄浸膏粉中去甲基麻黄碱、去甲基伪麻黄碱、麻黄碱、伪麻黄碱和甲基麻黄碱等 5种主要麻黄类生物碱。所用分离柱为HIQSILC18,流动相为含少量 (体积分数为 0 .2 % )甲醇的 0 .0 2mol L磷酸二氢钠溶液 (用HCl和三乙胺调至pH 3.2 )。 5种麻黄类生物碱在 2 5min内得到了有效分离、峰型对称且尖锐。     

Sensitive determination of ephedrine and pseudoephedrine by capillary electrophoresis with laser-induced fluorescence detection

A CE-LIF method was developed for the separation and sensitive detection of ephedrine and pseudoephedrine after derivatization by 4-chloro-7-nitrobenzo-2-oxa-1,3-diazol (NBD-C1). The derivatization and separation conditions were investigated in detail and the optimum conditions were obtained. Under the optimum experiment conditions, good linearity relationships (correlation coefficients: 0.9942 for ephedrine and 0.9970 for pseudoephedrine) between the peak heights and concentrations of the analytes were obtained (0.7-140 microM). The detection limits were 0.16 microM for ephedrine and 0.17 microM for pseudoephedrine, which indicated that the sensitivities were at least ten times improved over those reported in the literature obtained by UV detection. The method was applied to the analysis of ephedrine and pseudoephedrine in ephedra herb plants and preparations with good results.     

Method for derivatization of ephedrine and pseudoephedrine in nonaqueous media and determination by nonaqueous capillary electrophoresis with laser induced fluorescence detection

A nonaqueous capillary electrophoresis with laser-induced fluorescence detection method was developed for the quantification of ephedrine and pseudoephedrine after derivatization with 4-chloro-7-nitrobenzo-2-oxa-1, 3-diazol in nonaqueous media. The derivatization was made in off-line mode. By a series of optimizations, a derivatization buffer composed of 40 mm ammonium acetate and 20% acetonitrile and a running buffer composed of 80 mm ammonium acetate and 3% acetic acid were applied for the derivatization and separation of ephedrine and pseudoephedrine, respectively. Linear relationships for ephedrine and pseudoephedrine were obtained in the range 1.23-19.60 mg/L (correlation coefficients 0.9970 for ephedrine and 0.9994 for pseudoephedrine), and the detection limits for ephedrine and pseudoephedrine were 0.014 and 0.011 mg/L, respectively. The method was applied to the analysis of ephedrine and pseudoephedrine in four preparations with recoveries in the range 93.9-105.1%.     

高效毛细管电泳分离/电导检测麻黄碱和伪麻黄碱

采用高效毛细管电泳电导检测法分离麻黄碱和伪麻黄碱，初步探讨了分离机理，建立了检测方法。以柠檬酸－柠檬酸钠为缓冲体系，铜盐为络合剂，在pH值为4．5、电压13.5kV的条件下，盐酸麻黄碱和伪麻黄碱得到了较好的分离，加入适量乙醇可改善峰形和分离效果。用该法以水杨酰胺为内标，对含盐酸麻黄碱和伪麻黄碱的实际样品进行检测，回收率为97.3%-101.1%，结果令人满意。     

Analysis of ephedrine in ephedra callus by acetonitrile modified capillary zone electrophoresis

A simple method has been developed for the quantitative determination of ephedrine in ephedra callus. The dependence of effective mobility of ephedrine on pH was investigated, and a simulated equation was obtained. The separation was performed in an uncoated capillary and detected at 185 nm. A new Tris–NaOH–H₃PO₄ run buffer was used and the pH was adjusted to 3.20. To increase the solubility of hydrophobic analytes and improve the separation efficiency, 15% acetonitrile was used in the buffer as a modifier. The content of ephedrine in an ephedra callus sample and an ephedra herba sample were determined with this method, and the result was satisfactory.     

Separation and determination of ephedrine and pseudoephedrine in Ephedrae Herba by CZE modified with a Cu(II)-L-lysine complex

A CZE method using a complex of 2.5 mM Cu(II)-L-lysine (molar ratio is 1:2) as additive in a run buffer solution composed of Tris-H(3)PO(4) (pH 4.5) was developed for the simultaneous determination of ephedrine and pseudoephedrine within 4 min. The effects of pH, composition, and concentration of run buffer as well as the composition and concentration of the Cu(II)-L-lysine complex on the separation were investigated. The linear ranges for the determination of ephedrine and pseudoephedrine were 15.0-225.0 and 20.0-250.0 mg/L with LODs both of 5.0 mg/L. Satisfactory result for the determination of ephedrine and pseudoephedrine in Ephedrae Herba from different producing area was obtained by the proposed method. Ephedrine and pseudoephedrine were separated effectively with each other and with the other compounds in the sample. The RSD for the determination of the two constituents in the samples varied from 1.82 to 2.76%, and the recovery ranged between 95.0 and 104.0%.     

In-capillary derivatization and analysis of ephedrine and pseudoephedrine by micellar electrokinetic chromatography with laser-induced fluorescence detection

This paper describes an automatic rapid approach for in-capillary derivatization of ephedrine (E) and pseudoephedrine (PE) and subsequent sensitive determination of the derivatives by micellar electrokinetic chromatography (MEKC) with laser-induced fluorescence (LIF) detection using 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F) as fluorescent reagent. The unique feature of this method is the capillary being used as a small reaction chamber, in which the sample, derivatization buffer and reagent solutions were injected directly into the capillary by tandem mode, followed by an electrokinetic step (5 kV, 15s) to enhance the mixing efficiency of analytes and reagent plugs. Standing a specified time of 1 min for reaction, the derivatives were then immediately separated and determined. Several parameters for in-capillary derivatization and subsequent MEKC separation were systematically investigated. Under these optimized conditions, a baseline separation of the two analytes was achieved within 10 min and the derivatization concentration limits of detection were found to be 4.8 ng mL(-1) for E and 1.6 ng mL(-1) for PE, respectively. The method was validated in terms of precision, linearity, accuracy and successfully applied for the determination of the two alkaloids in ephedra herb and its preparations.     

Determination of diastereoisomeric alkaloids in urine by capillary electrophoresis with electrochemiluminescence detection

A new and simple capillary electrophoresis with electrochemiluminescence detection was developed for the separation and the quantification of a pair of diastereoisomenc alkaloids（ephedrine and pseudoephedrine）.The limits of detection（S/N = 3） were 4.5×10^-8 mol/L for ephedrine and 5.2×10^-8 mol/L for pseudoephedrine,respectively.The RSDs of migration time and peak area were less than 1.3 and 2.5%（n = 5）,respectively.The applicability of the propose method was illustrated in the determination of ephedrine and pseudoephedrine in human urine,ephedrine in nasal drops,and the monitoring of pharmacokinetics for pseudoephedrine.     

Determination of ephedrine and related compounds in pharmaceutical preparations by ion chromatography with direct conductivity detection

An ion chromatographic method with conductivity detection for the simultaneous determination of ephedrine, pseudoephedrine and norephedrine was developed. A mixture of 2.0 mmol/L HNO3 and 2% (v/v) acetonitrile was used as eluent. The three ephedrine-like compounds were separated and determined within 20 min. The linear ranges were 0.08-50 microg/mL for ephedrine, 0.08-40 microg/mL for pseudoephedrine and 0.06-40 microg/mL for norephedrine. The detection limits were 0.03 microg/mL for ephedrine and pseudoephedrine, and 0.02 microg/mL for norephedrine. The method has been applied successfully to the determination of these sympathomimetics in pharmaceutical preparations and in Ephedra herbs.     

Micellar electrokinetic chromatography with laser-induced fluorescence detection for sensitive determination of ephedrine and pseudoephedrine

A selective and sensitive micellar electrokinetic chromatography method with laser-induced fluorescence detection was developed for the quantification of ephedrine (E) and pseudoephedrine (PE) derivatized with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole. After conducting a series of optimizations, a running buffer of 10 mM sodium borate + 16 mM SDS was used for separation of the derivatives. A linear relationship for E and PE was obtained in the range of 0.044-6.6 microg mL(-1) (correlation coefficient: 0.9943 for E, 0.9946 for PE), and the detection limits for E and PE were 0.70 and 0.30 ng mL(-1), respectively. The sensitivity of E and PE was improved by several multiples of ten over those of CZE-LIF method. The method was applied to the analysis of the two alkaloids in ephedra herbal medicine and preparations with recoveries in the range of 98.3-107.1%.