毛细管电泳/发光二极管诱导荧光法测定麻黄中麻黄碱与伪麻黄碱含量

基于麻黄碱及伪麻黄碱衍生物的光谱及化学性质,设计并构建了毛细管电泳/发光二极管诱导荧光检测系统.对关键光学元件进行组合选择,以蓝光发光二极管为光源,BP 470和BP 530分别为光源滤光片和荧光滤光片,光电倍增管检测信号,并对电泳分离系统的缓冲溶液、分离电压等参数进行优化;以FITC为衍生试剂,10 mmol/L Na2B4O7+ 16 mmol/L SDS为缓冲溶液,12 kV电压下可实现麻黄中麻黄碱和伪麻黄碱的基线分离.在0.25～10 mg/L范围内,麻黄碱和伪麻黄碱标准溶液的质量浓度与荧光响应的峰高之间呈较好的线性关系,相关系数(r)均大于0.99,其检出限分别为0.38 μg/L和0.29 μg/L,峰高的日内重复性(RSD)分别为2.0％和2.2％,日间重复性(RSD)分别为5.4％和5.1％.将该方法用于中药麻黄中麻黄碱和伪麻黄碱的测定,加标回收率分别为94％和107％.     

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。     

Separation and determination of aconitine alkaloids in traditional Chinese herbs by nonaqueous capillary electrophoresis

An easy, rapid, and simple nonaqueous capillary electrophoresis (NACE) method was developed for the identification and determination of three aconitine alkaloids, hypaconitine (HN), aconitine (AN), and mesaconitine (MN) within 6 min. The most suitable running buffer was composed of 60 mM ammonium acetate, 0.5% acetic acid, and 15% acetonitrile (ACN) in methanol with a fused-silica capillary column (50 cm x 75 microm ID). In the concentration range 12.5-1000 mg/L the calibration curves reveal linear relationships between the peak area for each analyte and its concentration (correlation coefficients: 0.9997 for HN, 0.9999 for AN, and 0.9995 for MN). The relative standard deviations of the migration time and peak area of the three alkaloids were 0.13, 0.57, 0.33 and 2.87, 1.06, 3.49%, respectively. The method was successfully applied to determine the three alkaloids in two commonly used traditional Chinese herbal medicines, the recoveries of the three constituents ranging between 94.7-101.9% for HN, 98.3-102.3% for AN, and 98.1-104.6% for MN.     

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%.     

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.     

Optimization of the separation of Vinca alkaloids by nonaqueous capillary electrophoresis

A rapid method for the determination of Vinca alkaloids by nonaqueous capillary electrophoresis with diode array detection has been developed. A group of 11 alkaloids (catharanthine, vinorelbine, anhydrovinblastine, vinflunine, vindoline, 4-O-deacetylvinorelbine, 4-O-deacetylvinflunine, vindesine, vinblastine, 4'-deoxy-20',20'-difluorovinblastine, vincristine) could be readily separated within 10 min. The compounds were separated using a capillary of 38 cm effective length, a running buffer composed of 50 mM ammonium acetate and 0.6 M acetic acid in a methanol-acetonitrile (75:25, v/v) mixture. A constant voltage of 25 kV with a ramp time of 1 min and a 344.7 x 10(3) Pa pressure, applied simultaneously to inlet and outlet buffer vials, were used during sample analysis. Five of these alkaloids were selected for optimization of the separation and for validation studies with respect to specificity, linearity, range, limits of quantification and detection and then accuracy. The feasibility of the assay was demonstrated by analyzing a commercial sample of vinorelbine (Navelbine, ampoule at 10 mg/ml of vinorelbine base). The results were compared with a high-performance liquid chromatography method.     

Determination of quinolizidine alkaloids in traditional Chinese herbal drugs by nonaqueous capillary electrophoresis.

A rapid method for the determination of quinolizidine alkaloids by nonaqueous capillary electrophoresis was developed. A total of 10 alkaloids (matrine, sophocarpine, oxymatrine, oxysophocarpine, sophoridine, cytisine, sophoramine, aloperine, lehmannine and dauricine) could be easily separated within 18 min. A running buffer composed of 50 mM ammonium acetate, 10% tetrahydrofuran and 0.5% acetic acid in methanol was found to be the most suitable for this separation. Five of these alkaloids were selected for further studies. The linear calibration ranges were 2.51-50.1 microg/ml for sophoridine and sophocarpine, 2.71-54.2 microg/ml for matrine, 3.30-65.9 microg/ml for oxymatrine, and 3.10-62.0 microg/ml for oxysophocarpine. The recovery of the five alkaloids was 98.0-101.3% with relative standard deviations from 1.03 to 2.68% (n=5). The limits of detection for all 10 alkaloids were over the range 0.93-2.31 microg/ml. The method was successfully applied to the phytochemical analysis of alkaloid extracts from three commonly used traditional Chinese herbal drugs: Sophora flavescens Ait. (Kushen), S. alopecuroides L. (Kudouzi or Kugancao) and S. tonkinensis Gapnep (Shandougen).     

Rapid and ultrasensitive determination of ephedrine and pseudoephedrine derivatizated with 5-(4,6-dichloro-s-triazin-2-ylamino) fluorescein by micellar electrokinetic chromatography with laser-induced fluorescence detection

This paper presents a micellar electrokinetic chromatography method with laser-induced fluorescence detection to analyze ephedrine (E) and pseudoephedrine (PE) after derivatizated with 5-(4,6-dichloro-s-triazin-2-ylamino) fluorescein. The optimum derivatization conditions were: 0.05 M Na2CO(3/NaHCO3 (pH 9.5), reaction time 30 min at 45 degrees C, molar ratio of DTAF to E and PE mixture 20:1. The baseline separation was achieved within 8 min with running buffer composed of 20 mM borate+20 mM SDS+15% acetonitrile (v/v) (adjusted pH 9.8), and applied voltage of 20 kV. Good linearity relationships (correlation coefficients: 0.9906 for E and 0.9941 for PE) between the peak heights and concentration of the analytes were obtained (2.5-50 ngmL(-1)). The detection limits for E and PE were 3.85 x 10(-4) and 1.41 x 10(-4)ngmL(-1), respectively, which indicated that the proposed method surpassed other chromatographic alternatives in terms of limit of detection by at least 10(3) folds. The method was applied to the analysis of the two alkaloids in ephedra herb plants and its preparations with recoveries in the range of 89.6-107.0%.     

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.     

Micelle to solvent stacking of two alkaloids in nonaqueous capillary electrophoresis

This paper for the first time describes the development of micelle to solvent stacking (MSS) to nonaqueous capillary electrophoresis (NACE). In this proposed MSS-NACE, sodium dodecyl sulfate (SDS) micelles transport, release, and focus analytes from the sample solution to the running buffer using methanol as their solvent. After the focusing step, the focused analytes were separated via NACE. The focusing mechanism and influencing factors were discussed using berberine (BBR) and jatrorrhizine (JTZ) as model compounds. And the optimum condition was obtained as following: 50 mM ammonium acetate, 6% (v/v) acetic acid and 10 mM SDS in redistilled water as sample matrix, 50 mM ammonium acetate and 6% (v/v) acetic acid in pure methanol as the running buffer, -20 kV focusing voltage with 30 min focusing time. Under these conditions, this method afforded limits of detection (S/N=3) of 0.002 μg/mL and 0.003 μg/mL for BBR and JTZ, respectively. In contrast to conventional NACE, the concentration sensitivity was improved 128-153-fold.     

Separation and determination of epinephrine and dopamine in traditional Chinese medicines by micellar electrokinetic capillary chromatography with laser induced fluorescence detection

A micellar electrokinetic capillary chromatography method with laser-induced fluorescence detection was developed for the analysis of epinephrine and dopamine after derivatization with 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole. The optimum derivatization conditions were: 30 mM sodium borate (pH adjusted to 8.0 with 1.0 M HCl), reaction time 30 min at 60 degrees C. Baseline separation was achieved within 14 min with a running buffer composed of 10 mM sodium borate + 25 mM sodium dodecyl sulfate (pH adjusted to 9.5 with 0.1 M NaOH) and an applied voltage of 15 kV. Good linearity relationships (correlation coefficients: 0.9991 for epinephrine and 0.9985 for dopamine) between peak areas and concentrations of the analytes were obtained. The detection limits and quantification limits for epinephrine and dopamine were 0.0038 mg/L and 0.013 mg/L, and 0.065 mg/L and 0.020 mg/L, respectively. The method was applied to the analysis of the two compounds in two Chinese medicines with recoveries in the range of 92.6-108.7%.     

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。     

柱前衍生高效液相色谱法测定二乙醇胺脱氢产物亚氨基二乙酸和甘氨酸

以对甲苯磺酰氯(PTSC)为衍生剂,建立了柱前衍生高效液相色谱(HPLC)测定二乙醇胺脱氢产物中亚氨基二乙酸(IDA)和甘氨酸(Gly)含量的分析方法。IDA和Gly与衍生剂在碱性(pH 11)条件下于45℃反应15 min,进行柱前衍生,并利用高效液相色谱-质谱对衍生产物进行定性分析。衍生化产物采用VP-ODS色谱柱(200 mm×4.6 mm,5μm)分离,以0.03 mol/L醋酸铵溶液(pH 5.5)为流动相A、乙腈为流动相B(体积比为87∶13),进行等度洗脱,流速为1 mL/min,并采用配有紫外检测器的高效液相色谱仪测定,检测波长为235 nm。该法在IDA质量浓度为900~2 100 mg/L、Gly质量浓度为20~100 mg/L的范围内线性关系良好,相关系数(R2)均大于0.999。IDA和Gly的检出限(LOD)分别为0.089 7 mg/L和0.026 2 mg/L,加标回收率分别为98.7%~99.3%和98.0%~99.5%,相对标准偏差(RSD)分别为0.89%~1.23%和0.95%~1.11%(n=3)。该法具有反应条件温和、准确性高的特点,可用于工艺生产中IDA和Gly含量的测定。     

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

A selective and sensitive microemulsion electrokinetic chromatography with laser-induced fluorescence detection method was developed for the quantification of ephedrine (E) and pseudoephedrine (PE) derivatized with 4-chloro-7-nitrobenzo-2-oxa-1, 3-diazol. By a series of optimization, a running buffer composed of 20 mM borate + microemulsion (23.3 mM Sodium dodecyl sulfate/180.85 mM 1-butanol/16.4 mM n-heptane) +8% acetonitrile was applied for the separation of the derivatives. A linear relationship for E and PE was obtained in the range of 0.058-11.58 microg.mL(-1) (correlation coefficient: 0.9993 for E, 0.9995 for PE), and the detection limits for E and PE were 5.3 and 3.9 ng.mL(-1). The method was applied to the analysis of the two alkaloids in Chinese traditional herbal preparations with recoveries in the range of 96.9-105.4%.     

中空纤维液-液-液微萃取/HPLC分析人尿液中麻黄碱及伪麻黄碱

建立了中空纤维液-液-液微萃取高效液相色谱对人尿液中的麻黄碱和伪麻黄碱进行纯化、分离、富集以及测定的方法。采用中空纤维三相微萃取装置,考察了影响萃取的因素,确定了萃取条件:中空纤维壁上的有机相为正辛醇,以50μL盐酸溶液(pH 2.0)为接受相,在室温下萃取60 min。该条件下麻黄碱和伪麻黄碱的富集倍数分别为180倍和220倍,两者的线性范围分别为0.01～5 mg/L和0.005～0.75 mg/L,相关系数(r)分别为0.998 2、0.997 8,定量下限分别为0.01、0.005 mg/L。该方法使用极少量的有机溶剂,便可有效地对尿样中麻黄碱和伪麻黄碱进行纯化、分离和富集,萃取效率高,可用于尿液中麻黄碱和伪麻黄碱的同时测定。     

Separation and determination of ephedrine and pseudoephedrine by combination of flow injection with capillary electrophoresis

A simple, rapid, and accurate method for the separation and determination of ephedrine and pseudoephedrine using direct UV absorbance detection has been developed by the combination of flow injection with capillary electrophoresis for the first time. The buffer solution used is a 40 mM borate solution with the pH adjusted to 9.5 using a 2 M NaOH solution. The linear calibration range is 50 to 1000 microg/mL (r = 0.9996) for both analytes, and the recoveries are 91.2-108.2% for ephedrine and 92.6-107.3% for pseudoephedrine, respectively. The relative standard deviation of the peak area is 1.6% for ephedrine and 1.3% for pseudoephedrine (n = 6) at a concentration of 500 microg/mL, respectively. A series of samples is injected repeatedly without current interruption and subsequent rinsing, and the contents of these two alkaloids in three marketed drugs and the medical plant, Ephedra sinica, are determined with satisfactory results by this method.     

Micellar liquid chromatographic method for the determination of ephedrine and pseudoephedrine in human serum by direct inject of the sample with simple dilution

A micellar high-performance liquid chromatographic method was developed to simultaneously determine ephedrine and pseudoephedrine in human serum. The serum sample pretreatment was a simple dilution in a micellar solution, filtration, and direct injection, thus avoiding time-consuming and tedious steps. Hence, there is no need to use an internal standard. The serum samples were analyzed using a mobile phase containing 1.50?×?10^?1?mol/L sodium dodecyl sulfate and 0.02?mol/L sodium dihydrogen phosphate with 7.5% (v/v) 1-propanol at pH 3.0, running at 1.0?mL/min by an Inertsil C18 (150?×?4.6?mm, 5?µm) column at 30°C. The UV wavelength was set at 210?nm. The developed method was validated by linearity (r?>?0.9990) and intra- and inter-day precisions of ephedrine and pseudoephedrine (relative standard deviation; RSD%, 0.04–10.40, and RSD %, 0.30–10.25, respectively), LODs for ephedrine and for pseudoephedrine was 2.63 and 2.70?µg/mL, respectively; lower limit of quantification for ephedrine and for pseudoephedrine was 4.38 and 4.51?µg/mL, respectively. Finally, the proposed method was applied to investigate ephedrine and pseudoephedrine in real human serum samples after oral administration of Kechuanning Koufye including Ephedra herb. It is environmentally friendly, easy-to-handle, and feasible method for routine analysis in clinical laboratory.     

Separation and determination of active components in Radix Salviae miltiorrhizae and its medicinal preparations by nonaqueous capillary electrophoresis

A nonaqueous capillary electrophoresis (NACE) method was developed for simultaneous assay of three bioactive components (1: cryptotanshinone; 2: tanshinone IIA, and 3: tanshinone I) in Radix Salviae miltiorrhizae and in its herbal preparations for the first time. After optimization of separation conditions, a buffer of 250 mmol L(-1) ammonium acetate containing 30% acetonitrile and 1.0% acetic acid (V:V) in methanol was selected for separating the three analytes, but baseline separation of tanshinon I and tanshinone IIA was not obtained. Therefore second-order derivative electropherograms were applied for resolving overlapping peaks. Regression equations revealed good linear relationships (correlation coefficients 0.9943-0.9991) between peak heights in second-order derivative electropherograms and concentrations of the three analytes. The relative standard deviations (RSD) of the migration times and the peak height of the three constituents were in the range of 0.81 -0.88% and 0.34-1.13% (intra-day), 1.57-1.86% and 3.05-5.52% (inter-day), respectively. The recoveries of three constituents ranged from 90.2 to 108.5%. The results indicated that baseline separation of the analytes was sometimes hard to obtain and second-order derivative electropherograms were applicable for the resolving and analysis of overlapping peaks.     

Simple HPLC method for detection of trace ephedrine and pseudoephedrine in high-purity methamphetamine

A simple and sensitive HPLC technique was developed for the qualitative determination of ephedrine and pseudoephedrine (ephedrines), used as precursors of clandestine d‐methamphetamine hydrochloride of high purity. Good separation of ephedrines from bulk d‐methamphetamine was achieved, without any extraction or derivatization procedure on a CAPCELLPACK C₁₈ MGII (250 × 4.6 mm) column. The mobile phase consisted of 50 mM KH₂PO₄–acetonitrile (94:6 v/v %) using an isocratic pump system within 20 min for detecting two analytes. One run took about 50 min as it was necessary to wash out overloaded methamphetamine for column conditioning. The analytes were detected by UV absorbance measurement at 210 nm. A sample (20 mg) was simply dissolved in 1 mL of water, and a 50 μL aliquot of the solution was injected into the HPLC. The detection limits for ephedrine and pseudoephedrine in bulk d‐methamphetamine were as low as 3 ppm each. This analytical separation technique made it possible to detect ephedrine and/or pseudoephedrine in seven samples of high‐purity d‐methamphetamine hydrochloride seized in Japan. The presence of trace ephedrines in illicit methamphetamine may strongly indicate a synthetic route via ephedrine in methamphetamine profiling. This method is simple and sensitive, requiring only commonly available equipment, and should be useful for high‐purity methamphetamine profiling. Copyright © 2011 John Wiley & Sons, Ltd.     

Analysis of steroids by nonaqueous capillary electrophoresis

A simple method for the separation and determination of steroids (estradiol valerate, triamcinolone, levonorgestrel and ethinylestradiol) in single and compound tablets by nonaqueous capillary electrophoresis with ultraviolet (UV) spectrophotometric detection has been developed for the first time. After optimizing the electrophoretic parameters, including the nature of electrolytes and composition of organic solvent, the running buffers of methanol-acetonitrile (95: 5, v/v) containing 20 mM sodium acetate (pH 6.5) and methanol-acetonitrile (90: 10, v/v) containing 25 mM sodium acetate (pH 7.0) were found to be most suitable for determining estradiol valerate and triamcinolone, respectively. Reliable separation and simultaneous determination of levonorgestrel and ethinylestradiol were achieved in methanol containing 20 mM of ammonium acetate and 10 mM of sodium dodecyl sulfate (SDS). Tamoxifen was used as internal standard. Performance of the method, including migration time and peak area reproducibility, linearity, sensitivity and accuracy, were also evaluated. The limits of detection (S/N = 3) for four analytes were in the range of 9.8–19.5 μ g/mL. The relative standard deviations (RSD) of the migration times and peak areas of the analytes were in the range of 0.14–1.0% and 0.7–2.7% (intraday), 0.5–2.8% and 1.5–4.2% (interday), respectively. Within the tested concentration range, linear relationships between peak area ratios and concentrations of the analytes were obtained (correlation coefficients: 0.9987–0.9996). The method has been successfully applied to the determination of ingredients with recoveries over the range of 96.6–100.6%. The text was submitted by the authors in English.