Separation and determination of three phenylpropanoids in the traditional Chinese medicine and its preparations by capillary electrophoresis

Three phenylpropanoids (ferulic acid, chlorogenic acid, and caffeic acid) are simultaneously separated and determined within 13 min by a new capillary electrophoresis method using 15 mmol/L sodium borate (pH 8.71) as run buffer. The optimum conditions for the separation as well as the analytical characteristics, such as the calibration graph and limit of detection (LOD) for the determination of these three compounds, are studied. The linear range for the determination of ferulic, chlorogenic, and caffeic acid is 5.0 approximately 70.0, 8.0 approximately 112.0, and 9.0 approximately 64.0 microg/mL, with the LOD as 1.5, 2.25, and 6.0 microg/mL, respectively. The method, which is very simple, rapid, and of requisite sensitivity and reproduction, is satisfactorily used for the separation and determination not only of ferulic, chlorogenic, and caffeic acid in Cimicifuga foelida Li and its preparation (Yin-huang-han-pian), but also of ferulic acid and chlorogenic acid in Ligusticum chuanxiong hort. and Angelica sinensis (Oliv.) Diels.     

中药归尾的质量研究

应用高效液相色谱法对归尾中所含有效成分阿魏酸的含量进行测定,同时,对归尾药材的灰分和浸出物也进行了测定;结果表明：归尾含灰分7.27%,酸不溶性灰分1.62%,醇溶性浸出物56.2%,阿魏酸0.058%,为归尾的质量控制提供了初步的实验数据。     

Simultaneous determination of hydroxysafflor yellow A and ferulic acid in rat plasma after oral administration of the co-extractum of Rhizoma chuanxiong and Flos Carthami by HPLC-diode array detector

A simple, rapid and accurate HPLC method has been developed for simultaneous determination of hydroxysafflor yellow A and ferulic acid in rat plasma after oral administration of the co-extractum of Rhizoma chuanxiong and Flos Carthami. Plasma samples were deproteinized with 6% perchloric acid, and riboflavin was used as internal standard. The supernatant after centrifuge was injected into a Shimadzu C(18) (150 x 4.6 mm, i.d. 5 microm) column. Gradient elution for A:B (0 min, 90:10; 25 min, 70:30; 27 min, stop) was applied. The mobile phase was composed of 0.022 mol/L potassium dihydrogen phosphate solutions, adjusted to pH 3.0 with phosphoric acid for pump A, and 90% (v/v) acetonitrile for pump B. The assay was shown to be linear over the range 0.046-4.6 microg/mL (r(2) = 0.9995) for hydroxysafflor yellow A and 0.037-3.7 microg/mL (r(2) = 0.9998) for ferulic acid. Mean recovery was 97.5% for hydroxysafflor yellow A and 83.6% for ferulic acid. Both of the intra-day and inter-day precisions were 相似文献   

Separation and identification of the organic acids in Angelicae Radix and Ligustici Rhizoma by HPLC and CE

Angelicae Radix (AR) and Ligustici Rhizoma (LR) are both derived from the Umbelliferae plants and contain similar organic acids as their bioactive compounds. Nine of these organic acids, including nicotinic acid, protocatechuic acid, phthalic acid, folinic acid, p-hydroxybenzoic acid, folic acid, vanillic acid, caffeic acid, and ferulic acid were separated by HPLC and CE. Detection at 210 nm with a linear gradient containing 20 mM KH2PO4 (pH 3.5) and H2O-CH3CN in HPLC and with a buffer solution containing 10 mM LTAC, 2 mM Na2HPO4, 9 mM Na2B4O7(pH 9.56), and CH3CN in CE were found to be the most efficient eluents for this separation. The contents of the nine components in crude extracts of either AR or LR could easily be determined within 60 min by LC and within 20 min by CE. The structures of the individual peaks in the LC chromatogram were identified by LC-MS. The effects of buffers on the separation and validation of the two methods were examined.     

Rapid determination of cyclamate in foods by solid-phase extraction and capillary electrophoresis

A method for the determination of cyclamate in food was developed using solid-phase extraction (SPE) and capillary electrophoresis (CE) with indirect ultraviolet (UV) detection. A 5-10 g sample in 0.1 mol/L hydrochloric acid was homogenized and made up to a volume of 50 mL with 0.1 mol/L hydrochloric acid. After the sample was centrifuged, 25 mL of supernatant was loaded into an Oasis HLB SPE cartridge. The cartridge was washed with 2 mL of demineralized water followed by 2 mL of 50% aqueous methanol, and cyclamate was eluted with 4.5 mL of 50% aqueous methanol. The eluate was added to a solution of sodium propionate (internal standard) for CE analysis. The cyclamate in the eluate was electrophoresed on a fused-silica capillary using 1 mmol/L hexadecyltrimethylammonium bromide and 10 mmol/L potassium sorbate as a running buffer. Detection and reference wavelengths of cyclamate determined with a UV detector were 300 and 254 nm, respectively. The calibration curves for cyclamate showed good linearity in the range of 2-1000 microg/mL and the limits of detection in beverage, fruit in syrup, jam, pickles and confectionary are sample dependent and ranged from 5-10 microg/g. The recovery of cyclamate added at a level of 200 microg/g to various kinds of foods was 93.3-108.3% and the relative standard deviation was less than 4.9% (n=3). A number of commercial samples were analyzed using the proposed method. Cyclamate was detected in one waume, two pickles, and two sunflower seeds. The quantitative values determined with CE correlated to those from high-performance liquid chromatography (HPLC) (the detected values of cyclamate in a sunflower seed measured by CE and HPLC were 3.40 g/kg and 3.51 g/kg, respectively). This analytical method for cyclamate using CE is especially suitable for use in the field.     

Development and validation of a method for quantitative determination of econazole nitrate in cream formulation by capillary zone electrophoresis

A simple, fast, inexpensive and reliable capillary zone electrophoresis (CZE) method for the determination of econazole nitrate in cream formulations has been developed and validated. Optimum conditions comprised a pH 2.5 phosphate buffer at 20 mmol L(-1) concentration, +30 kV applied voltage in a 31.5 cm x 50 microm I.D. capillary. Direct UV detection at 200 nm led to an adequate sensitivity without interference from sample excipients. A single extraction step of the cream sample in hydrochloric acid was performed prior to injection. Imidazole (100 microg mL(-1)) was used as internal standard. Econazole nitrate migrates in approximately 1.2 min. The analytical curve presented a coefficient of correlation of 0.9995. Detection and quantitation limits were 1.85 and 5.62 microg mL(-1), respectively. Excellent accuracy and precision were obtained. Recoveries varied from 98.1 to 102.5% and intra- and inter-day precisions, calculated as relative standard deviation (RSD), were better than 2.0%. The proposed CZE method presented advantageous performance characteristics and it can be considered suitable for the quality control of econazole nitrate cream formulations.     

Determination of oleanolic acid and ursolic acid in cornel by cyclodextrin-modified micellar electrokinetic chromatography

A cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) method was established for the determination of oleanolic acid and ursolic acid in cornel. The two components were separated in the running buffer of 40 mmol/L sodium borate containing 5% methanol, 25 mmol/L SDS and 15 mmol/L hydroxypropyl-beta-cyclodextrin (HP-beta-CD). The applied voltage was 24 kV. The wavelength of detection was 200 nm. The temperature was kept at 25 C. Cinnamic acid was used as the internal standard. The analytical performance of the method was tested with respect to linearity, precision and recovery. The calibration curves were linear in the range of 10.15-243.6 microg/mL, r=0.9993 (oleanolic acid) and 10.07-241.7 microg/mL, r=0.9994 (ursolic acid); the intra-day precision (RSD) was less than 3.7% (oleanolic acid) and 4.1% (ursolic acid); the inter-day precision (RSD) was less than 4.2% (oleanolic acid) and 4.9% (ursolic acid). The limits of detection were 1.6 microg/mL for both components. The method proved to be sensitive, rapid, accurate and suitable for the determination of oleanolic acid and ursolic acid in cornel.     

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.     

毛细管区带电泳法测定冬虫夏草及鹿茸制品中核苷和碱基成分

应用毛细管区带电泳法测定分别以冬虫夏草菌丝体粉和鹿茸血为主要原料制品中的多种核苷和碱基成分。对实验条件进行了优化,结果表明,以20mmol/L硼砂-15mmol/Lβ-环糊精为缓冲溶液(pH=9.4),分离电压22kV,检测波长254nm,电动进样为10kV、5s时,在10min内同时分离测定了虫草素、腺嘌呤、鸟嘌呤、尿嘧啶、腺苷、次黄嘌呤、尿苷、鸟苷和肌苷。各组分在0.2～200μg/mL范围内呈线性关系,检出限的范围是0.07～1.67μg/mL。5个批次的冬虫夏草菌丝粉保健品中腺嘌呤、尿嘧啶、腺苷、鸟苷、尿苷5组分的定量结果分别在0.15～0.19mg/g、0.72～0.92mg/g、1.44～1.59mg/g、1.51～2.32mg/g和1.77～2.56mg/g范围内,加标回收率的范围是82.83%～109.21%;2个批次的鹿茸血保健品中次黄嘌呤、尿苷的定量结果在36.55～49.97μg/mL和86.08～108.97μg/mL范围内,加标回收率的范围分别是89.68%～96.79%和99.05%～102.81%。     

Simultaneous determination and pharmacokinetic studies on (3,4-Dihydroxyphenyl)-lactic acid and protocatechuic aldehyde in rat serum after oral administration of Radix Salviae miltiorrhizae extract

A simple and sensitive high-performance liquid chromatography method is developed for the simultaneous determination of (3,4-dihydroxyphenyl)-lactic acid (Dhpl) and protocatechuic aldehyde (Pal) in rat serum after oral administration of Radix Salviae miltiorrhizae extract. Serum samples are acidified with hydrochloric acid and extracted with ethyl acetate. Analysis of the extract is performed on a reversed-phase column and a mobile phase of 0.02% phosphoric acid-acetonitrile (91:9, v/v) with UV detection at 280 nm. Standard curves are linear in the range of 1.47-456.96 microg/mL for Dhpl and 0.124-7.936 microg/mL for Pal. For both regression coefficients, r(2) is greater than 0.993. Mean recovery is determined to be 75.23% and 84.06%, respectively, by analyzing serum standard containing 7.14, 57.12, and 228.48 microg/mL of Dhpl and 0.124, 0.992, and 3.968 microg/mL of Pal. The intraday precision (relative standard deviation) ranges from 3.91% to 12.03% at concentrations of 1.43, 57.12, and 228.48 microg/mL for Dhpl and 3.79% to 8.12% at concentrations of 0.124, 0.992, and 3.968 microg/mL for Pal. The interday precision (relative standard deviation) ranges from 5.06% to 9.93% for Dhpl and 3.05% to 10.00% for Pal, respectively, at the same three concentrations. This validated assay is applied to the determination of Dhpl and Pal concentrations and used to take a limited view of the pharmacokinetic profile in rat serum after oral administration of Radix Salviae miltiorrhizae extract.     

UV-absorbance detector for HPLC based on a light-emitting diode

A flow-through optical absorption detector for HPLC was constructed using a novel deep-UV light-emitting diode as radiation source with a peak emission wavelength of 255 nm. For measuring the transmitted intensity (a property correlated to Transmittance) a special UV-sensitive photodiode was employed. Besides the power source, no optical or electronic components other than an inexpensive operational amplifier and a few passive components were necessary. The performance of the detector was tested with three substances, namely nitrobenzene, benzoic acid and methyl benzoate, which were separated by gradient elution using an acetonitrile/water mixture and tetrabutylammonium hydrogensulfate as pH-buffer. Calibration curves for concentrations between 1.6 microg.mL(-1) and 400 microg.mL(-1) (nitrobenzene) and 8 microg.mL(-1) and 2.5 mg.mL(-1) (benzoic acid and methyl benzoate) were determined and coefficients of determination, r(2), of 0.9945, 0.9972 and 0.9996 were obtained for quadratic curve fits for the 3 compounds respectively. Relative standard deviations (n = 7) for peak areas were determined as 0.35% (nitrobenzene, 80 microg.mL(-1)), 0.27% (benzoic acid, 400 microg.mL(-1)) and 0.83% (methyl benzoate, 200 microg.mL(-1)). The lower limits of detection were found to be 750 ng.mL(-1), 5.8 microg.mL(-1) and 12 microg.mL(-1) for nitrobenzene, benzoic acid and methyl benzoate respectively.     

Determination of scopolamine, atropine and anisodamine in Flos daturae by capillary electrophoresis.

A capillary electrophoresis method was developed for the separation and determination of tropane alkaloids in Flos daturae plants. Separation was performed on a fused silica capillary(42.1 cm x 50 microm i.d.) at an applied voltage of 20 kV. Scopolamine, atropine and anisodamine were well separated in the buffer of 50 mmol/L phosphate buffer (pH 5.0) containing 20% (v/v) tetrahydrofuran (THF). Beer's law was obeyed in the range of concentration of 2.4-21.8 microg/mL for scopolamine, 4.0-36.0 microg/mL for atropine and 2.6-23.7 microg/mL for anisodamine, respectively, and the correlation coefficients were over 0.999 (n = 6). The developed method was applied for the analysis of herb samples.     

在线扫集-胶束毛细管电动色谱法测定扛板归中的阿魏酸、咖啡酸和原儿茶酸

采用在线扫集-胶束毛细管电动色谱法(sweeping-MEKC)分离测定扛板归中的阿魏酸、咖啡酸和原儿茶酸。采用未涂层熔融石英毛细管(50 cm×50μm,有效柱长36 cm);环境温度25℃;缓冲体系为20 mmol/L NaH2PO4-80mmol/L十二烷基磺酸钠(SDS)-12.5%乙腈(V/V)(pH 2.20),紫外检测波长为216 nm,运行分离电压-20 kV,进样时间100 s。在优化条件下,3种有机酸均在20 min内出峰,峰面积RSD均小于5%。检出限分别达到98.52,118.73和27.27μg/L。     

Capillary electrochromatography of selected phenolic compounds of Chamomilla recutita

This article explores the use of capillary electrochromatography for the analysis of chamomile (Chamomilla recutita L.) extracts. After a thorough study of analytical parameters such as mobile and stationary phase composition, applied voltage, and temperature, a methodology to determine 11 bioactive phenolic compounds (coumarins: herniarin, umbelliferone; phenylpropanoids: chlorogenic acid, caffeic acid; flavones: apigenin, apigenin-7-O-glucoside, luteolin, luteolin-7-O-glucoside; flavonols: quercetin, rutin and flavanone: naringenin) in chamomile extracts was proposed. The method was performed in a Hypersil SCX/C18 column with pH 2.8 phosphate buffer at 50 mmol L(-1) containing 50% acetonitrile (pH adjusted before the addition of the organic solvent). All compounds were separated in less than 7.5 min under isocratic conditions. Figures of merit include linearity (peak area versus apigenin concentration) from 50.0-1000 microg/mL (r2=0.995), and intra-day precision of retention time and peak area better than 1.3% CV and 15%, respectively. The limits of detection and quantification for apigenin were 35.0 microg/mL and 150.0 microg/mL, respectively. This article also describes an NMR 1H study, carried out to monitor a new clean-up procedure for extracts containing propyleneglycol, whose components are poorly retained in conventional octadecyl silica cartridges.     

超高效液相色谱-电喷雾三重四极杆质谱法测定中药中马兜铃酸A和B的含量

利用超高效液相色谱-电喷雾三重四极杆质谱仪建立了中药中马兜铃酸A和B的定性定量分析方法。选取柴胡、生甘草、桔梗、龙胆泻肝丸、消胖丸、减肥茶等14种代表性样品,用甲醇-水(70:30, v/v)溶液加热回流提取,经Oasis MAX固相萃取柱富集净化后,在Eclipse RP HD C18反相柱(150 mm×2.1 mm, 1.8 μm)上进行分离;流动相为5 mmol/L乙酸铵水溶液(pH 7.5)-乙腈(75:25, v/v)。采用电喷雾离子源正离子模式(ESI+)和多反应监测模式(MRM)进行质谱分析。马兜铃酸A和B的线性范围分别为0.5～200 μg/L和1～200 μg/L,相关系数(r2)均大于0.995;检出限(LODs)分别为5 μg/kg和7.5 μg/kg;定量限(LOQs)分别为12.5 μg/kg和25 μg/kg。在100 μg/kg和500 μg/kg添加水平下,马兜铃酸A和B的回收率(n=6)范围分别为60.3%～96.4%和61.3%～94.7%,相对标准偏差均不大于10.2%。该方法灵敏度高,重复性好,操作简便,适用于中药材、饮片及中成药中马兜铃酸A和B的痕量检测。     

高效液相色谱法测定大鼠血浆中的原儿茶酸

建立了大鼠血浆中原儿茶酸含量测定的高效液相色谱方法。采用的色谱柱为DiamondsilTM C18 柱(150 mm×4.6 mm,5 μm);流动相为乙腈-水(体积比为9∶91,用H3PO4 调pH至2.5);流速1.2 mL/min;检测波长260 nm;内标为对羟基苯甲酸。原儿茶酸的线性范围为0.050~3.20 mg/L,线性相关系数为0.9978，最低定量限为0.050 mg/L,日内和日间测定的精密度（以相对标准偏差表示）均低于7.0%,准确度（以相对误差表示）为-1.4%～2.6%；在0.050,0.40,3.20 mg/L低、中、高3个添加浓度水平下，血浆样品的提取回收率分别为83.4%,87.3%,91.1%。该方法简便,灵敏,准确,适用于大鼠体内原儿茶酸的药物动力学研究。     

电堆集富集非水毛细管电泳同时测定水杨酸、肉桂酸、阿魏酸和香草酸

建立了同时分离测定水杨酸、肉桂酸、阿魏酸和香草酸的电堆集富集-非水毛细管电泳(NACE)的新方法。运行缓冲溶液为40mmol/L乙酸钠-2.5mmol/L氢氧化钠甲醇溶液,电压-25kV,在225nm波长下紫外检测。对电压、乙酸钠浓度、氢氧化钠浓度、进样时间、样品溶液等因素对电堆集及分离的影响做了系统的研究。水杨酸、肉桂酸、阿魏酸和香草酸分别在1.4~28mg/L、0.40~8.0mg/L、0.7~18mg/L和0.7~30mg/L范围内线性关系良好(r=0.9999、r=0.9997、r=0.9994、r=0.9997);回收率分别为95.8~99.6%、96.2~98·2%、95.7~105%和98.9~103%,基于3倍信噪比(S/N=3),4种有机酸的检出限分别为0.069、0.051、0.107和0.089mg/L。     

固相萃取-离子色谱法测定地下水中痕量高氯酸根离子

建立了测定地下水中痕量高氯酸根（ClO~4）的固相萃取-离子色谱(SPE-IC)分析方法。0.7 L水样经预处理降低主要干扰离子Cl~、CO2~3和SO2~4的干扰后,使用Cleanert PWAX弱阴离子交换固相萃取小柱对地下水中痕量(μg/L级)的ClO~4进行富集,用6 mL 1%NaOH溶液洗脱,富集液经0.45 μm水膜过滤后,用IonPac AS20阴离子分离柱、50 μL进样环、40 mmol/L KOH溶液淋洗、抑制电导检测分离分析。结果表明,地下水样品中ClO~4的方法检出限和测定下限分别为0.15 μg/L和0.60 μg/L,进样质量浓度在1～15 μg/L范围内有很好的线性关系,线性相关系数为0.9992,回收率为99.7%～100.5%;该方法经济有效,可用于地下水中痕量ClO~4的检测。利用该方法测定了哈尔滨周边部分地区地下水中ClO~4浓度,检测结果与离子色谱-质谱联用法的检测结果的相对误差为1.85%～9.24%。     

微透析与高效液相色谱在线联用技术校正大鼠皮下阿魏酸线性探针

采用微透析与高效液相在线联用技术(MD-HPLC on-line)建立并验证大鼠皮下阿魏酸微透析线性探针体内外校正方法.以磷酸盐缓冲溶液为灌流液,微透析灌注液流速为2 μ L/min,10孔自动进样阀间隔为8 min,在以Hypersil-C18(250 mm×4.6 mm,5μm)为色谱柱,流动相为甲醇-水(含0.5％乙酸)(35∶ 65,V/V),流速1 mL/min,检测波长314 nm的HPLC色谱条件下进行在线检测,阿魏酸在0.1～80 mg/L范围内回归方程线性关系良好,A=159044C-2607 (r=1),阿魏酸日内精密度RSD分别为0.8％,0.3％和0.5％(n=5);日间精密度RSD分别为0.2％,0.3％和0.4％(n=5),重现性与稳定性RSD分别为0.7％和1.1％(n=5).增量法和减量法测定阿魏酸线性探针体内外回收率分别为47.23％±0.94％和20.37％±1.37％,阿魏酸适宜进行微透析实验.应用MD-HPLC on-line对中药当归阿魏酸进行测定,使取样、进样和分析监测同时进行.     

二元环糊精体系对柴胡中柴胡皂苷a与柴胡皂苷d的毛细管电泳分离测定

以磺丁基-B-环糊精(SBE-β-CD)和β-环糊精(β-CD)组成二元手性选择体系,用毛细管电泳法对柴胡中的柴胡皂苷a及柴胡皂苷d进行分离测定.考察了缓冲液的组成和浓度、手性选择剂的组成和浓度、进样方式及样品介质等对灵敏度和分离度的影响.结果表明:采用熔融石英毛细管柱(60 cm×50 μm i.d,有效长度为53 ...