OBJECTIVETo investigate the effect of different chromatographic conditions on QAMS relative correlation factors (RCF) and relative retention values (RT(R)).

METHODC18 columns were used with methyl alcohol-0.4% phosphoric acid water (85: 15) as the mobile phase. The detection wavelength was 254 nm, the column temperature was 30 degrees C, and the flow rate was 1.0 mL x min(-1). The five anthraquinones in Rhei Radix et Rhizoma were selected to be the objects of study. The RCF and RT(R) among aloe-emodin, rhein, chrysophanol, physcion and emodin were determined under different chromatographic conditions.

RESULTTheir RCFs showed no significant difference.

CONCLUSIONThe RCFs among anthraquinones established by QAMS can be used as a constant in content determination of traditional Chinese medicines/patent traditional Chinese medicines.

OBJECTIVETo evaluate the quality of Polygonum perfoliatum collected from GAP planting base efficiently so as to provide scientific evidence for its GAP tending plant by HPLC fingerprinting method.

METHODAnalysis was performed on a reserved-phase column Lichrosher-C18 column (4.6 mm x 250 mm, 5 microm), A linear gradient elution of 0.2% aqueous acetic acid and acetonitrile was used for the separation.

RESULTWildlife tending P. perfoliatum was relatively stable. The chromatograms of the samples from 2011 were more accordant than those from 2010. Samples in Dafang were the most stable and had little differences during the two years. The quality of P. perfoliatum planted in the regions of sample GBG-(GD) 002 in Guiding and sample GBG-(LL) 003 in Longli were more stable and better than those from other regions.

CONCLUSIONIt is a feasible method that can be used to evaluate the quality of P. perfoliatum for GAP planting.

Objective: To establish a method for the rapid determination of acetaminophen (APAP) in human plasma by LC-MS/MS. Methods: The plasma samples were extracted by methanol and acetonitrile (1: 1) and purified directly. C(18) column was used for sample separation. The mobile phase were methanol (5 mmol/L ammonium acetate) and water (5 mmol/L ammonium acetate). Samples were analyzed by LC MS/MS with the electrospray ionization multi reaction monitoring (MRM) mode. Results: The calibration curves of APAP was linear in the concentration range of 0~10 mg/L, the correlation coefficient (r) was greater than 0.999 0. The relative standard deviation within and between batches was less than 10%. The recovery rate were 96.81%~101.7%. The detection limit of the method was 0.1 μg/L and the lower limit of quantification was 0.3 μg/L. Conclusion: This method has strong specificity, high sensitivity and reliable determination results. It is suitable for the rapid analysis of clinical plasma samples.
Humans ; Chromatography, Liquid/methods* ; Acetaminophen ; Tandem Mass Spectrometry/methods* ; Methanol ; Chromatography, High Pressure Liquid/methods*

OBJECTIVES: To establish a simple and rapid qualitative and quantitative detection method of dexmedetomidine in blood. METHODS: Blood was separated on the Allure PFP Propyl liquid chromatography column with isocratic elution after it was precipitated by acetonitrile and filtered. Qualitative and quantitative analysis of dexmedetomidine was performed using positive ion scan mode and multi-reaction monitoring mode. RESULTS: The limit of detection of dexmedetomidine in blood was 0.2 ng/mL and the limit of quantification was 0.5 ng/mL. The linearity of the method was good in the range of 0.5-1 000 ng/mL, and the correlation coefficient was greater than 0.99. The accuracy of the method was 90.34%-112.67% and the extraction recovery was 50.05%-91.08%, with no significant matrix effect. CONCLUSIONS This method is simple, selective and suitable for the qualitative and quantitative analysis of dexmedetomidine in blood, which can provide a reference for drug-facilitated cases involving dexmedetomidine.
Tandem Mass Spectrometry/methods* ; Chromatography, High Pressure Liquid/methods* ; Dexmedetomidine/analysis* ; Reproducibility of Results ; Chromatography, Liquid/methods*

OBJECTIVETo establish a precolumn chiral derivatization method for determination of fexofenadine enantiomers, a chiral substrate of OATP1B1, in cellular model.

METHODSR-(+)-phenylethyl isocyanate was selected as chiral derivatization reagent, which was reacted with fexofenadine to form carbamate derivatives. Enantiomers were identified by LC/MS and separated by RP-HPLC.

RESULTSUnder the experimental conditions, the fexofenadine enantiomers were separated completely. The standard curve was linear over the concentration range of 25-100 ng/ml (R(2)=0.9992, 0.9989). Accuracy was 101.1% and 98.3%, intra-precision was 2.4% and 3.1%, inter-precision was 3.1% and 4.0% for D1 and D2, respectively.

CONCLUSIONThe method established is sensitive and accurate for determination of fexofenadine enantiomers in cells.

Neuronal histamine is crucially involved in a number of physiological functions as well as in neuropsychiatric diseases. Determination of histamine in biological samples is thus of importance in the clinical studies. The aim of this review is to summarize the progress or effort made in this field, with focus on the high-performance liquid chromatography.
Chromatography, High Pressure Liquid ; methods ; Histamine ; analysis ; cerebrospinal fluid ; Humans

This study is to establish the characteristic HPLC chromatogram of phenols in Ephedrae Herba, from which to pick out the marker peaks, followed by the analysis of the regularity of their distribution and content in the herbaceous stems of Ephedra sinica, E. intermedia and E. equisetina. The HPLC-DAD method for the characteristic chromatogram as well as quantitative analysis was established. The separation was carried out on a YMC-Pack ODS-A column (4.6 mm x 250 mm, 5 µm), eluted with the mobile phases as 0.01% formic acid aqueous solution (A) and acetonitrile (B) in a linear gradient (0-10 min, 17% B; 10-25 min, 17%-19% B; 25- 33 min, 19%-48% B; 33-35 min, 48%-51% B; 35-44 min, 51% B). The flow rate was kept at 1.0 mL · min⁻¹. The column tem- perature was 40 °C, and the detection wavelength was set at 350 nm (0-16 min) and 330 nm (16-44 min). Forty-six batches of collected samples from three official origins of Ephedrae Herba were detected, whose liquid chromatograms proven to be helpful to the differentiation of different origins. With principal component analysis and the analysis of distribution of peak area, twelve key peaks from the chromatogram were discussed in details on their contributions to the characteristics and differences of three official origins of the herb: peak area of peak 10, 11, 12 were found out to be significantly higher in E. equisetina than in other two origins, whose sum (higher than 146 mAU in E. equisetina) was useful for the discrimination between E. equisetina and the other two origins; peak area of 1 and 4 were respectively higher in E. sinica and E. intermedia than in other official origins, indicating their important effect on the differen- tiation of corresponding origins; peak 8 and 9 were picked out as two characteristic common peaks in three official origins of the herb, whose peak area showed little difference among different origins; further, peak area of other key peaks in the chromatogram also showed some difference among three origins, which make contributions to the differentiation of origins as well. Then, four phenols as 2"-O-α- L-rhamnosyl-isovitexin (1), vitexin (2), pollenitin B (5) and herbacetin-7-O-β-D-glucoside (6) were quantitative analyzed with the above-mentioned method, with good linear relationship and accuracy (recoveries in a range of 97.8%-102.5%). The content of the four phenols were firstly reported in Ephedrae Herba from official origins, which were respectively trace-1.55 (1), trace-0.160 (2), trace-0.284 (5) and trace-0.620 (6) mg · g⁻¹ in all of the tested samples. In addition, the content of these phenols showed differences in three official origins, especially 1, whose content in E. sinica [(0.670 ± 0.88) mg ± g⁻¹] were significantly higher than in other two origins (lower than 0.16 mg ± g⁻¹ besides sample Ei-060630-2-2), and 6, whose average content in E. equisetina [(0.260 ± 0.039 2) mg · g⁻¹] were twice as high as in E. sinica [(0.120 ± 0.270) mg · g⁻¹] and E. intermedia [(0.136 ± 0.485) mg g⁻¹], indicating the important effects of the two constituents on the differentiation among three official origins of the herb. The method established for the characteristic HPLC chromatogram and quantitative analysis of phenols was simple and accurate, and the marker constituents selected may provide new guides for the discrimination of official origins as well as the improvement of quality criteria of EphedraeHerba.
Chromatography, High Pressure Liquid ; methods ; Ephedra ; chemistry ; Phenols ; analysis

This study established an HPLC fingerprint of Tibetan medicine Shaji Gao from different habitats and lay a foundation for Shaji Gao varieties identification and preparation process. The chromatographic condition was as follow: Agilent zorbax SB-C18 (4.6 mm x 250 mm, 5 μm) eluted with the mobile phases of acetonitrile and 0.4% phosphoric acid water in gradient mode. The flow rate was 1.0 mL x min(-1), and the detection wavelength was set at 360 nm. The fingerprints of 15 batches Shaji Gao were carried out by similarity comparation, 7 chromatographic peaks were extracted as the common peaks of fingerprint, 3 peaks were identified, which were quercetin, kaempferol and isorhamnetin. The similarity degrees of 14 batches of samples were above 0.9 and 1 batch of samples was below 0.9. This is the first established fingerprint of Shaji Gao by using HPLC. This method has good precision, stability and repeatability that it could provide basis for quality control and evaluation of Shaji Gao.
Chromatography, High Pressure Liquid ; methods ; Medicine, Tibetan Traditional ; Quality Control

OBJECTIVETo establish a method for determining the content of alpha-lipoic acid in New Zealand rabbit plasma.

METHODSAlpha-lipoic acid in the plasma samples was purified by solid-phase extractor and analyzed on an HYPERSIL C18 column with isocratic mobile phase consisting of potassium dihydrogen phosphate-acetonitrile (50:50, v/v) at a flow rate of 1.0 ml/min and detection wavelength of 230 nm.

RESULTSThe standard curve was linear in the range of 5-100 microg/L (r=1) and the average recovery was 77.4%-82.1%. The relative standard deviations of intra-day and inter-day assay were within 1.5%-8.9%.

CONCLUSIONThe method is sensitive, accurate and simple for determining plasma alpha-lipoic acid levels in New Zealand rabbits.

OBJECTIVETo establish the chromatographic fingerprint for the quality control of gamboge.

METHODAnalysis on a Luna C8 (4.6 mm x 250 mm, 5 microm) column eluted with mobile phases containing acetonitrile and 0.1% glacial acetic acid in water in gradient mode. The flow rate was 1.0 mL x min(-1) and the detection wavelength was at 362 nm. The temperature of column was 25 degrees C. And data of 11 batches of gamboge samples from different sources were analysed by "similarity evaluation for chromatographic Fingerprint of Traditional Chinese Medicine" software.

RESULTThirteen common peaks were selected in chromatograms, and all the common peeks were separated effectively.

CONCLUSIONThe precision, repeatability, and stability of this method were satisfying. The method developed can be used to identify and evaluate the quality of gamboge.