OBJECTIVETo establish the analytical method for the fingerprint of Radix et Rhizoma Rhei by MEKC-DAD and compare the fingerprints of Radix et Rhizoma Rhei and its processed products.

METHODBased on the mode of micellar electrokinetic chromatography, 25 mmol x L(-1) borax -25 mmol x L(-1) SDS-10% acetonitrile was selected for the running buffer (pH 9.2). The separation voltage was 12 kV and the detection wavelength was set at 254 nm. Rhein was used as a reference standard, the chromatographic fingerprint was determined via the data analyzed by fuzzy cluster and fingerprint similarity evaluation software to compare the similarity of samples.

RESULTMEKC-DAD fingerprints with 11 common peaks of 10 batches of Radix et Rhizoma Rhei from the place of the genuine were established preliminarily. It was discovered that a small number of samples differed from others. Regarding to the fingerprints of Radix et Rhizoma Rhei and its processed products, there were obvious differences in the relative areas of common peaks.

CONCLUSIONThe method is reliable, accurate and can be used for quality control of Radix et Rhizoma Rhei.

Chromatography, Micellar Electrokinetic Capillary ; methods ; Drugs, Chinese Herbal ; chemistry ; Rhizome ; chemistry

Chromatography, Micellar Electrokinetic Capillary ; methods ; Liposomes ; Membranes, Artificial ; Pharmaceutical Preparations ; chemistry

OBJECTIVEA Micellar electrokinetic chromatography (MEKC) technique for the determination of ginsenosides Re, Rb1 in Panax quinquefolius was developed and validated.

METHODThe MEKC was performed in a mixed buffer solution containing 20 mmol x L(-1) boric acid, 20 mmol x L(-1) sodium tetraborate, 60 mmol x L(-1) sodium cholate (CA) and 20% acetonitrile under the applied voltage of 20 kV at 25 degrees C. The detection wavelenth was 203 nm, the sampling time is 5 sec (hydrostatic injection).

RESULT AND CONCLUSIONThe liner range was 0.38 - 1.65 mg x ml(-1) for Re and 0.42 - 1.76 g x L(-1) for Rb1. The average recovery for Re was 97.2%, RSD = 1.6% and that for Rb1 was 97.7%, RSD = 1.9% (n = 5). The preparation of sample is easy and the chromatogram has much information.

Chromatography, Micellar Electrokinetic Capillary ; Ginsenosides ; analysis ; Panax ; chemistry ; Plant Roots ; chemistry ; Plants, Medicinal ; chemistry ; Quality Control

The present study determined five saponins in Xuesaitong Dropping Pills(XDP) by micellar electrokinetic chromatography(MEKC), and evaluated between-batch consistency by MEKC fingerprints and similarity analysis. A background buffer was composed of 20 mmol·L~(-1) sodium tetraborate-20 mmol·L~(-1) boric acid solution(pH 8.5), 55 mmol·L~(-1) sodium dodecyl sulfate(SDS), 23 mmol·L~(-1) β-cyclodextrin, and 13% isopropyl alcohol. All separations were performed at 25 ℃,20 kV and the detection wavelength was set at 203 nm. The separation channel was a fused silica capillary with a dimension of 75 μm I.D. and a total length of 50.2 cm(effective length of 40.0 cm). The contents of notoginsenoside R_1, and ginsenosides Rg_1, Re, Rb_1, Rd were determined with their quality control ranges set. The fingerprints of XDP were established and the between-batch consistency was evaluated by similarity analysis. The contents of five saponins from the 19 batches of XDP were stable in the fixed ranges. Statistical analysis was carried out on the results of multiple batches of samples, and the specific quality control ranges were recommended as follows: notoginsenoside R_1 21.92-34.16 mg·g~(-1), ginsenosides Rg_1 83.54-131.78 mg·g~(-1), ginsenosides Re 13.58-19.82 mg·g~(-1), ginsenosides Rb_1 89.40-129.90 mg·g~(-1), and ginsenosides Rd 22.34-35.67 mg·g~(-1). Eleven characteristic peaks were identified in the fingerprints. Five peaks, notoginsenoside R_1 and ginsenosides Rg_1, Re, Rb_1, Rd, were identified with reference standards. The similarities of the 19 batches of samples were all above 0.988, indicating good between-batch consistency. This method is green and simple, and can be used for the quantitative determination and quality evaluation of XDP. It can also provide references for the quality control of other Chinese medicinal dripping pills.
Chromatography, Micellar Electrokinetic Capillary ; Drugs, Chinese Herbal ; Micelles ; Quality Control ; Saponins

OBJECTIVETo establish an instant determination method of emodin, aloe-emodin and rhein, from Rheum, and one of their preparations, Qinghai Wild Dahuang Tea, by micellar electrokinetic capillary electrophoresis for the first time.

METHODSeparation was carried out in an uncoated fused silica capillary (75 microm x 50.0 cm). Meanwhile, a running voltage 20 kV, 15.0 mmol x L(-1) borax buffer with 30.0 mmol x L(-1) SDS and 10% ethanol (pH 9.60) and a UV detector at 254 nm were adopted.

RESULTThe linear calibration rang was 4-120 mg x L(-1) (r = 0.992 1) for emodin, 10-200 mg x L(-1) (r = 0.997 0) for aloe-emodin, and 2-100 mg x L(-1) (r = 0.997 1) for rhein, respectively. Under the optimum conditions, the relative standard deviation (RSD) values (n = 6) for the migration time and the peak area of each peak were 0.59%-0.80%, 1.30%-3.22%, respectively. The contents of the analytes were easily determined with recoveries ranging from 97.6%-102.3%.

CONCLUSIONThe method is proved to be simple, rapid and accurate, and can be used for the quality control of medicinal herb, Rheum, and its tea preparation.

Anthraquinones ; analysis ; Chromatography, Micellar Electrokinetic Capillary ; methods ; Emodin ; analysis ; Plant Preparations ; chemistry ; Plants, Medicinal ; chemistry ; Rheum ; chemistry

A micellar electrokinetic capillary chromatography method with ultraviolet detection was developed for the simultaneous determination of psoralen, xanthotoxin, isoimpinellin, bergapten and scopoletin in Radix Glehniae. The separation was performed on an uncoated fused silica capillary column (50.2 cm x 75 microm x 40 cm) with 20 mmol x L(-1) borax solution (pH 9.6) containing 16 mmol x L(-1) sodium dodecylsulfate (SDS) and 15% acetonitrile as running buffer at applied voltage of 22 kV. The detection wavelength was 214 nm. The effects of concentrations of borax solution, sodium dodecylsulfate (SDS), and organic modifier, voltage, temperature on the separation and sensitivity were investigated. The five active constituents were completely separated within 7 min. The linear ranges of psoralen, xanthotoxin, isoimpinellin, bergapten and scopoletin were 9.91-82.6, 37.2-162, 2.23-18.6, 2.73-22.3 and 2.89-20.1 mg x L(-1), respectively. And the average recoveries were 98.9%, 98.4%, 101.3%, 99.1% and 98.0%, respectively. This simple and rapid method provided a new basis for assessment on quality of Radix Glehniae.
Apiaceae ; chemistry ; Chromatography, Micellar Electrokinetic Capillary ; methods ; Coumarins ; analysis ; isolation & purification ; Drugs, Chinese Herbal ; analysis ; isolation & purification ; Plant Roots ; chemistry

The current status and latest advances in new technique pseudophase biochromatography are reviewed. After brief introduction to the principle of new technique pseudophase biochromatography, the nature and various influence factors including the compositions, the types of new technique pseudophase biochromatography system are summarized in detail and the aspects of the future applications biochromatography in life science are described.
Animals ; Biotechnology ; methods ; Chromatography, Liquid ; methods ; Chromatography, Micellar Electrokinetic Capillary ; methods ; Electrophoresis, Capillary ; methods ; Humans ; Lipid Bilayers ; chemistry ; Liposomes ; Retinoids ; isolation & purification

AIMTo establish separation methods of five sulfonamides by using capillary high performance liquid chromatography(mu-HPLC) and electrochromatography. The effect of mobile phase varies such as methanol content, pH, buffer solution concentration and voltage on their chromatographic behavior and electroosmesis flow was investigated. Capillary electrochromatography (CEC) was compared with mu-HPLC at the same condition.

METHODSStationary phase was ODS, mobile phase was methanol and 2 mmol.L-1 H3PO4 buffer solution (pH 3.0-7.0), voltage was 0- -15 kV, flow rate was 10 microL.min-1, pressure was approximately 70 MPa and UV detection wavelength was 254 nm.

RESULTSSeparations on base line have been respectively accomplished for five sulfonamides by mu-HPLC with mobile phase of methanol-2 mmol.L-1 H3PO4 buffer solution (30:70) at pH 5.0 in 67 min, and CEC with the same mobile phase at -5 kV voltage in 25 min.

CONCLUSIONElectroosmesis flow of CEC decreased with the increase in methanol content, buffer solution concentration, increased with the increase in voltage and increase slightly with the increase in pH of mobile phase. Retention values (k) of solutes to be examined decreased with increasing methanol content of mobile phase in mu-HPLC and CEC. Retention values (k) of solutes increased slightly with increasing buffer solution concentration, decreased with increasing voltage in CEC. Trimethoprim(TMP) decreased obviously with increasing voltage in CEC. The effect of pH of mobile phase on retention values (k) was more complex. Five sulfonamides were separated at the same mobile phase condition by mu-HPLC and CEC. And separation speed of CEC was much faster than that of mu-HPLC. CEC was very fit for rapid separation of sulfonamides.

Anti-Infective Agents ; isolation & purification ; Buffers ; Chromatography, High Pressure Liquid ; methods ; Chromatography, Micellar Electrokinetic Capillary ; methods ; Hydrogen-Ion Concentration ; Sulfonamides ; isolation & purification ; Trimethoprim ; isolation & purification

AIMSTo establish a novel microemulsion electrokinetic chromatography (MEEKC) method for measuring lipid-water partition coefficients ( logP(ow)) of pharmaceuticals without using microemulsion phase marker in order to avoid the error from tracing the migration time of microemulsion phase.

METHODSThe migration time of microemulsion phase (t(me)) was obtained by non-linearity fitting with logP(ow) values from literature and measured migration time (t(m)) of a series of organic compounds, a calibration curve for estimating logP(ow) of pharmaceuticals was thus obtained. In addition, the accuracy of the values measured by MEEKC was evaluated.

RESULTSThe logP(ow) values of 4 pharmaceuticals measured by MEEKC method presented in this paper were close to those determined by shake-flask method, and the average error between values from two methods was 0.15 logarithm units. Furthermore, according to the suggested theory, the measurement accuracy of logP(ow) is correlated with different t(m) in MEEKC.

CONCLUSIONThe proposed method is simple, rapid, reproducible, and reliable with high measurement accuracy, which can be useful to estimate lipid-water partition coefficients of pharmaceuticals.

Acetaminophen ; chemistry ; Acyclovir ; chemistry ; Chromatography, Micellar Electrokinetic Capillary ; methods ; Doxazosin ; chemistry ; Emulsions ; Lipids ; chemistry ; Pharmaceutical Preparations ; chemistry ; Reproducibility of Results ; Water ; chemistry

AIMTo determine six effective components (aloe-emodin, rhein, emodin, rhaponticin, physcion and chrysophanol) in Rheum.

METHODSUsing buffer solution containing 20 mmol.L-1 borax, 20 mmol.L-1 sodium deoxycholate (SDC), 20 mmol.L-1 sodium taurocholate (STC), 15 mmol.L-1 beta-cyclodextrin (beta-CD) and O-phthalic acid as the internal standard, the six components were determined by cyclodextrin modified micellar electrokinetic chromatography.

RESULTSIn less than 25 min, aloe-emodin, rhein, emodin, rhaponticin, physion and chrysophanol were separated. The separation conditions were optimized by adjusting buffer pH, concentrations of SDC, STC and beta-CD. The linearity ranges of aloe-emodin, rhein, emodin, rhaponticin, physcion and chrysophanol were 4-34, 5-40, 4-60, 5-80, 6-90 and 5-85 micrograms.mL-1 respectively. Relative standard deviation (RSD) of the method was less than 2.2%. The recoveries of aloe-emodin, rhein, emodin, rhaponticin, physcion and chrysophanol were 100.0%, 98.3%, 100.4%, 94.6%. 95.2% and 93.8% respectively. Raw Rheum, Mongolian Rheum and Rheum tanguticum samples were analyzed.

CONCLUSIONThis method can be an effective one for identification of Rhubarb.

Anthraquinones ; analysis ; Chromatography, Micellar Electrokinetic Capillary ; methods ; Cyclodextrins ; chemistry ; Emodin ; analogs & derivatives ; analysis ; Plants, Medicinal ; chemistry ; Quality Control ; Rheum ; chemistry ; Stilbenes ; analysis