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

Chromatography, Gas ; methods ; Triazoles ; blood

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

Metabonomics involves the unbiased quantitative and qualitative analysis of the complete set of metabolites present in cells, body fluids and tissues (the metabolome) based on modern analytic technique with high throughput, high sensitivity, and high resolution. Gas chromatography-mass spectrometry (GC-MS) is used to gain qualitative results of detected metabolites for biological samples as it provides superior distinguishability, detection sensitivity and integrated standard mass spectrometry library. In this article, the historic developments of GC-MS and its application in metabonomics in the past several years were reviewed. Firstly, the classification and the derivative methods of GC-MS were introduced. Subsequently, sample pretreatment process, qualitative and quantitative analysis and data analysis during detecting metabolites by GC-MS were introduced, then its application in microorganism, plant and disease diagnosis was systematically summarized. Finally, the problems in metabonomics study based on GC-MS and the research prospect in the future were discussed.
Gas Chromatography-Mass Spectrometry ; methods ; Metabolomics ; methods

OBJECTIVETo establish a method for simultaneous determination of 17 common pesticides in whole blood by solid phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS).

METHODSWhole blood samples were treated by extraction with acetonitrile, and the obtained extract was cleaned up using an Oasis HLB SPE cartridge; pesticides were separated by GC and quantitatively analyzed by MS with selected ion monitoring.

RESULTSThe concentrations of 17 pesticides in whole blood were 1.0-5.0 mg/L, and the recovery rate was 41.3-102.1%, with a relative standard deviation of less than 10%in most pesticides. The 17 pesticides showed a good linear relationship between concentration and peak area within 0.5-5.0 mg/L, with a correlation coefficient of 0.9945-0.9994. The limit of detection and limit of quantification were 0.02-0.05 mg/L and 0.05-0.09 mg/L, respectively.

CONCLUSIONWith this method, 17 pesticides in whole blood can be well separated and determined. This method has high sensitivity, accuracy, and precision and can be used for identification and quantification of multiple pesticides in blood samples.

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*

At the summer workshop of the Korean Endocrine Society held in 2016, some examples of protein experiments were discussed in the session entitled “All about working with proteins.” In contrast to what the title suggested, it was unrealistic to comprehensively discuss all protein analytical methods. Therefore, the goal was to outline protein experimental techniques that are useful in research or in bench work. In conversations with clinicians, however, I have always felt that researchers who do not engage in bench science have different demands than those who do. Protein research tools that are useful in bench science may not be very useful or effective in the diagnostic field. In this paper, I provide a general summary of the protein analytical methods that are used in basic scientific research, and describe how they can be applied in the diagnostic field.
Chromatography ; Education ; Immunoenzyme Techniques ; Methods* ; Molecular Imaging

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

A simple, fast GC method based on headspace single drop microextraction (HS-SDME) was used for the determination of menthol and methyl salicylate in Baicao oils. A special sample pretreatment method was performed by adding 10 microL the oil its methanol solution into 5 mL water in a caped 10 mL sample vial, a 1.5 microL microdrop of N,N-dimethylformamide with benzyl alcohol as internal standard was formed on the pinpoint of microsyringe needle, exposing 5 min at extraction temperature of 40 degrees C. After extraction, 0.5 microL of extract was directely injected into GC for analysis. The determination was carried out on a capillary column (0.53 mm x 30 m) with PEG as the stationary phase with FID as the detector. A temperature programm was employed. The excellent separation and detection of the target components was accomplished. The average recoveries varied between 95.4% and 99.2%, and relative standard deviations were less than 1.9%. The calibration curves were linear in the range of 1.26-80.5 mg x L(-1) for menthol (r = 0.999 0) and 2.49-1.59 x 10(2) mg x L(-1) for methyl salicylate (r = 0.999 1), respectively. The proposed method is proved to be simple, fast, accurate and low cost without complicated sample pretreatment HS-SDME is expected to be widely applied for the analysis of volatile components in traditional Chinese medicines.
Calibration ; Chromatography, Gas ; methods ; Oils, Volatile ; analysis