High-performance countercurrent chromatography (HPCCC) coupled with reversed-phase high-performance liquid chromatography (RP-HPLC) method was developed to isolate dihydrophaseic acid 3′-O-β-D-glucopyranoside (DHPAG) from the extract of Nelumbo nucifera seeds. Enriched DHPAG sample (2.3 g) was separated by HPCCC using ethyl acetate/n-butanol/water system (6:4:10, v/v/v, normal-phase mode, flow rate: 4.0 mL/min) to give 23.1 mg of DHPAG with purity of 88.7%. Further preparative RP-HPLC experiment gave pure DHPAG (16.3 mg, purity > 98%). The current study demonstrates that utilization of CCC method maximizes the isolation efficiency compared with that of solid-based conventional column chromatography.
Chromatography ; Chromatography, Liquid ; Countercurrent Distribution ; Methods ; Nelumbo

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 develop an UPLC method of determining the characteristic chromatographic profile of Persicae Semen for controlling the drug quality quickly and accurately.

METHODThe UPLC characteristic chromatographic profiles of fifteen batches of Persicae Semen were determined on an HSS T3 column (2.1 mm x 100 mm, 1.8 microm) eluted with the mobile phase consisted of acetonitrile-water containing 0.05% phosphoric acid in gradient mode and the detection wavelength was at 254 nm.

RESULTThe common mode of the UPLC characteristic chromatographic profile was set up. There were 12 common peaks in the fingerprints of fifteen samples, six of which were identified, and the similar degrees of the fifteen batches to the common mode were between 0.884-0.996.

CONCLUSIONThe method was quick and accurate. The characteristic chromatographic profile of Persicae Semen with high specificity can be used to control the quality of Persicae Semen.

OBJECTIVETo develop an UPLC method of determining the characteristic chromatographic profiles of Paeoniae Radix Alba for quality control.

METHODThe UPLC characteristic chromatographic profiles of fifteen batches of Paeoniae Radix Alba were determined on an HSS T3 Column (2.1 mm x 100 mm, 1.8 microm) eluted with the mobile phases of water containing 0.05% phosphoric acid and acetonitrile in gradient mode. The detection wavelength was set at 230 nm.

RESULTThe common mode of the UPLC characteristic chromatographic profile was set up. There were 15 common peaks, five of which were identified, and the similar degrees of the fifteen samples to the common mode were between 0.891 and 0.996.

CONCLUSIONThe method was time-saving and can be used for the quality control of Paeoniae Radix Alba.

A simple and sensitive liquid chromatographic method was developed for quantification of cefotetan disodium (CTT), a semi-synthetic cephamycin antibiotic, in human plasma. CTT and the internal standard chloramphenicol were extracted from plasma by a simple one-step protein precipitation with 35% (v/v) perchloric acid. Separation was carried out on a reverse-phase C18 column with a mobile phase of acetonitile-water containing 0.5% (v/v) phosphoric acids (20:80, v/v) at a flow rate of 1.0 mL/min. The column effluent was monitored by UV detection at 300 nm. The column temperature was maintained at 40°C. This method demonstrated good linearity in the range of 0.525-300.0 μg/mL, with correlation coefficients greater than 0.99. The limit of quantification (LOQ) was 0.525 μg/mL in human plasma. Intra- and inter-day precisions were less than 6.63% in terms of relative standard deviation (RSD). The accuracy, when expressed by the bias, ranged from 0.57% to 4.04%. The mean extraction recovery of CTT was higher than 40.94%. The method was found to be precise, accurate, and specific for CTT quantitative analysis, and was successfully applied for a pharmacokinetic study of CTT after a single intravenous dose of 1.0 g of CTT in healthy Chinese subjects.
Cefotetan ; blood ; pharmacokinetics ; Chromatography, Liquid ; methods ; Humans

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*

OBJECTIVES: To establish a method for the simultaneous quantitative analysis of etomidate and its metabolite etomidate acid in blood, and to discuss its application value in actual cases. METHODS: Acetonitrile precipitate protein method was used, and C₁₈ column was selected. Gradient elution was performed with acetonitrile and 5 mmol/L ammonium acetate within 6 min. Electrospray ionization source in positive ion mode was used. The internal standard etomidate acid-d₅ was obtained by etomidate-d₅ alkaline hydrolysis reaction. Ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used for quantitative analysis. The methodological verification was conducted. RESULTS: Etomidate and etomidate acid in blood showed good linear relationship in the quantitative linear range (r>0.999), with the lower limit of quantification was 2.5 ng/mL and 7.5 ng/mL, respectively. The accuracy, precision, recovery rate, and matrix effect of the method met the professional verification standards. The practical application results showed that etomidate and etomidate acid could be detected in the blood of the abusers, and their mass concentrations ranged from 17.24 to 379.93 ng/mL. CONCLUSIONS The method established in this study can simultaneously quantify etomidate and etomidate acid in blood, which is simple and convenient to operate with accuracy. It can meet the detection needs of actual cases and provide technical support for law enforcement to crack down on etomidate abuse.
Chromatography, High Pressure Liquid/methods* ; Chromatography, Liquid ; Etomidate ; Tandem Mass Spectrometry/methods* ; Liquid Chromatography-Mass Spectrometry ; Acetonitriles

Biocompatible Materials ; analysis ; Chromatography ; methods ; Chromatography, Gas ; methods ; Chromatography, Liquid ; methods ; Paraquat ; analysis ; Pesticide Residues ; analysis