Separation and determination of ephedrine alkaloids and tetramethylpyrazine in Ephedra sinica Stapf by gas chromatography-mass spectrometry.

A simple, sensitive, and reliable method using gas chromatography (GC)-mass spectrometry (MS) is developed for the simultaneous determination of ephedrine alkaloids and 2,3,5,6-tetramethylpyrazine (TMP) in Ephedra sinica Stapf. The sample is extracted with ethyl ether and submitted to GC-MS for identification and quantitation without derivatization. The column used for GC is an HP-5 (30.0 m x 250 microm x 0.25 microm, 5% phenyl methyl siloxane), and the carrier gas is helium. The detection limits for ephedrine, pseudoephedrine, and TMP are 0.4 ng 0.7 ng, and 0.02 ng (signal-to-noise ratio of 3), respectively. The reproducibility of the total procedure is proved to be acceptable (RSD < 2%), and the recoveries are above 93%.

Simultaneous determination of p-hydroxybenzaldehyde, p-hydroxybenzyl alcohol, 4-(beta-D-glucopyranosyloxy)-benzyl alcohol, and sugars in Gastrodia elata blume measured as their acetylated derivatives by GC-MS.

A method for the simultaneous separation and determination of the active constituents and three sugars in the roots of Gastrodia elata Blume (GE), which is used as a famous Chinese traditional herbal medicine, by gas chromatography-mass spectrometry is established. The samples are acetylated with pyridine-acetic anhydride. The contents of 4-hydroxybenzaldehyde, 4-hydroxybenzyl alcohol (HA), fructose, glucose, 4-(beta-D-glucopyranosyloxy)-benzyl alcohol (GA), and sucrose in GE are 0.004%, 0.03%, 1.36%, 1.12%, 1.97%, and 4.25%, respectively, and the detection limits are 1.5, 3.0, 11.0, 5.0, 33.0, and 35.0 pg, respectively. The contents of HA and GA in the urine and brain of a mouse are also determined. This method is simple, reliable, and quick for the simultaneous determination of the active constituents and sugars in GE.

[Separation and determination of ephedrine alkaloids and 2,3,5,6-tetramethyl pyrazine in Ephedra herba by HPLC].

A sensitive and reliable high performance liquid chromatographic method(HPLC) has been developed for the first time for the simultaneous determination of the active ingredients of ephedrine alkaloids and 2,3,5,6-tetramethyl pyrazine (TMP) in Ephedra herba crude drug and two Chinese traditional medicines (Xiao-er qingfeiwan and Lu-si kewan). The HPLC assay was performed on a reversed phase C18 column (Nova-Pak C18, 3.9 mm i.d. x 150 mm) by using methanol-0.02 mol/L KH2PO4-acetic acid-triethyl amine (4:96:0.2:0.01, V/V) as mobile phase for the ephedrine alkaloids analysis and methanol-H2O-acetic acid (35:65:0.5, V/V) as mobile phase for TMP analysis. Regression equations revealed the linear relationships (correlation coefficients: 0.991-0.998) between the peak area of each constituent (E, PE, NE, NPE, TMP) and its concentration. The detection limits for E, PE, NE, NPE and TMP were 0.4 mg/L, 0.1 mg/L, 0.03 mg/L, 0.02 mg/L and 0.03 mg/L, respectively, and the recoveries ranged between 92%-103%. The contents of E, PE, NE, NPE, TMP in Ephedra herba, traditional medicine Xiao-er qingfeiwan and Lu-si kewan were determined respectively. The relative standard deviations (RSD) of the contents ranged between 1.1%-3%.

[Chromatographic analysis of tea polyphenols].

A review is presented about the chromatographic analysis of the polyphenols. Some of the chromatographic methods such as plate chromatography, gas chromatography, reversed-phase high performance liquid chromatography and some new chromatographic methods are introduced.

[Determination of tetramethylpyrazine in animal serum and cerebrospinal fluid by high performance liquid chromatography].

A reversed-phase high performance liquid chromatographic (RP-HPLC) method for the determination of the tetramethylpyrazine(TMP) in Chuanxiong extract, the animal(mouse) serum and cerebrospinal fluid has been developed. The TMP was separated on an ODS column Zorbax SB-C18(4.6 mm i.d. x 250 mm, 5 microns) at room temperature and detected by using UV detector at 270 nm. The mobile phase was methanol-water (50:50, V/V) containing 0.2 mmol/L of NH4H2PO4 flowing at a rate of 0.8 mL/min and 20 microL samples were injected. The detection limit of TMP was 1 mg/L and the calibration curve is linear between 5 and 500 mg/L with a correlation coefficient (r) of 0.999. The recovery of TMP ranged 98%-103%. The extract of Chuanxiong and pretreated serum and cerebrospinal fluid sample are stable for a week at room temperature.

[Studies on the active constituents of sichuan liang shan rhododendron L. I. Determination of two flavonoids in leaves, extracts and jinjuan liquors].

A reversed-phase HPLC method for the separation and determination of the two flavonoids: quercetin and kaempferol is described. The column was 25 cm x 4.6 mm i.d., packed with Zorbax SB-C18(5 microns). The mobile phase was a mixture of MeOH-H2O (60:40, V/V). The flow rate was 0.7 mL/min. UV detection was performed at 360 nm. External standard was used and the calibration curves showed good linearity over the range of 6.0-100 mg/L, r = 0.9995-0.9998, and detection limits were 3.3-6.2 mg/L. The recoveries were 96.0% and 97.3% for quercetin and kaempferol respectively. The relative standard deviations of the method were 2.1%-4.5%. The method is simple, fast, sensitive and accurate and can be applied to the analysis of quercetin and kaempferol. It provides a scientific basis for industrial production and quality control of Jinjuan liquor preparations for clinical uses.

[Determination of ferulic acid in chuanxiong and in animal serum and cerebrospinal fluid by reversed-phase high performance liquid chromatography].

An easy, rapid and sensitive method for the determination of ferulic acid(FA) in Chuanxiong extracts, animal (mouse) serum and cerebrospinal fluid by RP-HPLC has been developed. The FA was separated on an ODS column, Nova-Pak C18(3.9 mm i.d. x 150 mm) and detected at the wavelength of 320 nm. The mobile phase was methanol-water-acetic acid (35:65:0.5, V/V), with a flow rate of 0.8 mL/min. The detection limit of FA was 1.7 micrograms/L(S/N = 3) and the calibration curve was linear within the range of 0.85 mg/L-4.00 mg/L(r = 0.99904, n = 6). The mean recovery from animal serum and cerebrospinal was 95%-102%.