A suitable liquid chromatography quadrupole time-of-flight mass spectrometric (LC–Q-TOF–MS) method was developed for separation and characterization of related substances in bacitracin test drug. The separation was performed on LiChrospher RP-18 column using methanol as mobile phase A and 0.2% ammonium acetate buffer solution as mobile phase B in gradient elution. A total of 12 related substances were detected through high resolution mass spectrometric determination in a positive electrospray ionization mode. They were identified as co-existing active components and degradation products of bacitracin through the analysis and elucidation of both the protonated parents and the product ions of all the related substances and their fragmentation pathways were also proposed.

Novel aminopropyl-functionalized periodic mesoporous organosilicas (APMO) were successfully prepared by co-condensation of 1,2-bis (triethoxysilyl) ethane (BTSE) and 3-aminopropyltriethoxysilane (APTES) with the template of cationic surfactants cetyltrimethylammonium chlorine (C_(18)TAC) in basic medium.With the characterization measurements of powder X-ray diffraction (XRD),FT-IR and scanning electron microscopy (SEM) so on,APMO had such advantages as good monodisperse microshperes,uniformly orderd mesopore and large specific surface areas.These mesoporous materials were directly considered to be the chromatographic stationary phases and analyzed by HPLC evaluation.During the research,the as-prepared APMO column had better permeability and three polycyclic aromatic compounds realized separation.In addition,the as-prepared APMO column had certain advantages in fast analysis.

Protein phosphorylation is one of the most common post-translational modifications (PTMs)in various organisms,which plays critical roles in the regulation of intracellular biological processes,such as cell prolifera-tion,signal transduction,metabolismis and tumorigenesis.However,the low abundance of phosphoprotein in the biological systems poses significant challenges of current analytical techniques.In order to further understand the phosphoproteomics,the roles of phosphorylated proteins in life process,discovery of biomarkers,diagnosis and treatment of disease,enrichment strategies of high efficiency have been developed,including the design of new nanomaterials and combination of a variety of analytical methods,et al.In this paper,we reviewed the develop-ment of enrichment strategies for phosphoproteomics and application of phosphoproteomics in disease.

In this paper, chemical derivatization-high performance liquid chromatography was used to determine the potential genotoxic impurities chloroacetyl chloride and chloroacetic acid, respectively, in the raw material of azintamide.Derivatization was carried out using 2-nitrophenylhydrazine followed by the determination.Separation was performed on a Thermo Syncronis C18 column (250 mm × 4.6 mm, 5 μm), with mobile phase consisting of 0.1% phosphoric acid in water (A) and acetonitrile(B) by gradient elution, at a flow rate of 1 mL/min.The column temperature was 40 °C and the detection wavelength was 226 nm.The blank solvent, derivatization reagent, and azintamide did not interfere with the peak of the test substance, and the target component was well separated from the others.For impurities chloroacetyl chloride and chloroacetic acid, the limits of detection (LOD) were 7.5 ng/mL and 15 ng/mL respectively. There was a good linear relationship between the integral area and the concentration in the range of 30-300 ng/mL.The sample recovery rate was in the range of 87.37% ~ 109.75%.The two methods established in this study have good specificity, good precision, high sensitivity and simple operation, which can be used for the trace determination of potential genotoxic impurities chloroacetyl chloride and chloroacetic acid in the raw material of azintamide.

OBJECTIVETo investigate the toxic effects of Glucoside Tripterygium total on rats with nuclear magnetic resonance (NMR)-based metabonomic method.

METHODThe influence of intragastric administration of Glucoside Tripterygium total suspension at two different doses on endogenetic metabolites in normal rat urine was determined with bio-NMR method then analyzed by pattern recognition technique and partial least-squares discriminant analysis (PLS-DA). Histopathological analysis was carried out.

RESULTEscalations of concentrations of urinary taurine, TMAO and glucose as well as reductions of concentrations of urinary citrate and 2-oxoglutarate were found by analysis of the 1H-NMR spectra, which was coincident with the result of histopathological analysis. The result of pathological examination indicated that pathologic change was not observed in nephridial tissue, but there were obvious changes in hepatic tissue.

CONCLUSIONThe urinary metabomic spectra were closely associated with the hepatic toxicity, which manifested the mitochondrial dysfunctions, the abnormal energy metabolism in TCA cycle as well as the abnormal glucose metabolism.

Animals ; Citric Acid ; urine ; Enteral Nutrition ; Glucose ; metabolism ; Glucosides ; administration & dosage ; Ketoglutaric Acids ; urine ; Least-Squares Analysis ; Liver ; drug effects ; metabolism ; pathology ; Magnetic Resonance Spectroscopy ; methods ; Metabolomics ; Methylamines ; urine ; Plant Extracts ; administration & dosage ; Rats ; Tablets ; administration & dosage ; Taurine ; urine ; Tripterygium ; chemistry

The conventional equilibrium dialysis and ultrafiltration methods cannot be used to determine the protein binding of some peptides because of their non-specific adsorption on the semipermeable membrane or poor stability in the plasma. The method of dextran-coated charcoal adsorption combined with LC-MS/MS were used. Based on the kinetic principle of initial rate of candidate drugs absorbed to dextran-coated charcoal, seven phosphorylated peptides with the same amino acid sequence and different configurations in rat plasma were selected as the study model using; the protein binding in rat plasma were determined; the amino acid distribution rules affecting the changes in protein binding rates of peptide candidate drugs were summarized. The results suggest that the dextran charcoal adsorption method, as a supplementary method for the determination of plasma protein binding, is suitable for peptides or organic drug candidates that cannot be determined by traditional techniques.

A quantitative analysis method based on solid phase extraction-ultra performance liquid chromatography-tandem mass spectrometry (SPE-UPLC-MS/MS) for simultaneous determination of illicit drugs and their metabolites in wastewater was established. Samples filtered at pH of 2 and spiked with internal standard were loaded to Oasis Prime MCX cartridges for solid-phase extraction. The samples were washed with 4 mL of methanol and eluted with 4 mL of 5% ammonia in acetonitrile before reconstituting with 0.1% formic acid/water solution. ZORBAX Eclipse Plus C18 column was used for chromatography, and gradient elution was performed with 0.1% formic acid/water solution and acetonitrile as mobile phase. The samples were then detected by electrospray ionization (ESI) in positive ion mode, and multiple reaction monitoring mode (MRM) was adopted for quantitative analysis. All analytes had a good linear relationship (r ≥ 0.993 2) within the range of their respective standard curve; the limit of quantification was 1 ng/L (except amphetamine at 2.5 ng/L); the extraction recovery ranged from 82.13% to 99.96%; and the intra- and inter-day precisions were less than 9.43%. The method is accurate, reliable and reproducible, and is suitable for the quantitative determination of illicit drugs and their metabolites in wastewater and can provide an analytical method for real-time monitoring of drug abuse.

GC-MS and LC-MS are the main techniques used for the structural identification of new psychoactive substances at present. However, they are hard to give accurate structure information because of the hardly available corresponding reference standards and the quickly changing status of these compounds. This leads tremendous obstacle on the rapid identification of new psychoactive substances. Nuclear magnetic resonance spectroscopy is one of the most effective methods for structures identification. Therefore, NMR is especially suitable for the analysis and identification of new psychoactive substances even with rapid structural changes. This article summarizes the NMR applications for the structural analysis of new psychoactive substances including synthetic cannabinoids, synthetic cathinones, piperazines, phenethylamines, ketamine & phencyclidine-type substances, and fentanyls. It is found that the NMR signals of the main frame structure of each kind of the new psychoactive substances are basically the same. Hence, these frame structure NMR signals can provide scientific evidence for the rapid identification of new psychoactive substances. This article also look ahead the prospect for the application of LC-NMR and DOSY in new psychoactive substances, which provides new ideas for the screening of new psychoactive substances.

To develop a rapid and sensitive liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for the determination of endogenous glutathione in rat plasma. Glycyltyrosine was used as the internal standard(IS)and 4-(N-maleimido)phenyl trimethylammonium iodide(MPTA)was used as the derivation reagent. Chromatographic separation was achieved on a Zorbax HILIC PLUS column(4. 6 mm×100 mm, 3. 5 μm)and the mobile phase consisted of acetonitrile and 0. 1% formic acid(75 ∶25)pumped at a flow rate of 1. 0 mL/min. Detection was carried out on a triple quadrupole tandem mass spectrometer by selected reaction monitoring(SRM)in the can meet positive ion mode. The linearity ranged from 3. 000 to 2 000 ng/mL(r=0. 997 1); and the limit of detection of glutathione in rat plasma was 10 pmol/L. Matrix effect, stability, precision and accuracy of the method met the requirements. The proposed method was proved to be selective and sensitive, which is suitable for the quantification of endogenous glutathione in rat plasma.

In this study,we developed a novel on-line solid phase extraction (SPE)-ultra-high-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS)-based analytical method for simulta-neously quantifying 12 illicit drugs and metabolites (methamphetamine,amphetamine,morphine,co-deine,6-monoacetylmorphine,benzoylecgonine,3,4-methylenedioxymethamphetamine,3,4-methylenedioxyamphetamine,cocaine,ketamine,norketamine,and methcathinone) and cotinine(COT) in wastewater samples.The analysis was performed by loading 2 mL of the sample onto an Oasis hydrophilic-lipophilic balance cartridge and using a cleanup step (5％ methanol) to eliminate interference with a total run time of 13 min.The isotope-labeled internal standard method was used to quantify the target substances and correct for unavoidable losses and matrix effects during the on-line SPE process.Typical analytical characteristics used for method validation were sensitivity,linearity,precision,repeatability,recovery,and matrix effects.The limit of detection (LOD) and limit of quantification (LOQ)of each target were set at 0.20 ng/L and 0.50 ng/L,respectively.The linearity was between 0.5 ng/L and 250 ng/L,except for that of COT.The intra-and inter-day precisions were ＜10.45％ and 25.64％,respec-tively,and the relative recovery ranged from 83.74％ to 162.26％.The method was used to analyze various wastewater samples from 33 cities in China,and the results were compared with the experimental re-suits of identical samples analyzed using off-line SPE.The difference rate was between 19.91％and-20.44％,and the error range could be considered acceptable.These findings showed that on-line SPE is a suitable alternative to off-line SPE for the analysis of illicit drugs in samples.