OBJECTIVES: To analyze the chemical structure of the interfering substance that affects the result of methamphetamine analysis in wastewater. METHODS: A combination of GC-MS and liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) was used to analyze the mass spectrum characteristics of the interfering substance that affects the result of methamphetamine analysis and to infer its possible structure. Liquid chromatography-triple quadrupole-mass spectrometry (LC-TQ-MS) was used to confirm the control material. RESULTS: Using LC-QTOF-MS in positive electrospray ionization (ESI⁺) mode, the mass-to-charge ratio (m/z) of quasi-molecular ion in the MS¹ mass spectrometry of interfering substance was identical to that of methamphetamine, indicating that the interfering substance was probably an isomer of methamphetamine. The MS² mass spectra obtained at three collision energies of 15 V, 30 V and 45 V were highly similar to methamphetamine, suggesting that the interfering substance contained methylamino and benzyl groups. Further analysis using GC-MS in electron impact (EI) ionization mode showed that the base peak in the mass spectrum of the interfering substance was at m/z 44. The interfering substance was confirmed to be N-methyl-2-phenylpropan-1-amine by compared with the standard reference. CONCLUSIONS The chemical structure of N-methyl-2-phenylpropan-1-amine is highly similar to methamphetamine, which is easy to cause interference for the detection of trace amounts of methamphetamine in wastewater using LC-TQ-MS. Therefore, in the actual analysis, the chromatographic retention time can be used to distinguish between N-methyl-2-phenylpropan-1-amine and methamphetamine.
Methamphetamine ; Wastewater ; Amines ; Gas Chromatography-Mass Spectrometry/methods* ; Mass Spectrometry/methods* ; Spectrometry, Mass, Electrospray Ionization/methods*

To elucidate further sequence selectivity and nature of the binding of anticancer drugs to DNA, the interaction between anticancer drugs, which are minor groove ligands (distamycin A, DM and netropsin, NP) and intercalator (mitoxantrone, MT), and DNA were studied by electrospray ionization mass spectrometry. The 2 : 1 specific complex of DM and AT-rich DNA were observed principally, while only 1 : 1 specific complex of NP and AT-rich DNA were observed. MT specifically binds to GC-rich DNA. In addition, DM binds to DNA containing 5 A/T bases minor groove almost in a 2 : 1 mode and does not bind to DNA containing 3 A/T bases minor groove. NP binds most strongly to DNA containing 4 A/T bases minor groove. The 1 : 1 specific complex of MT and 6-mer DNA was also observed. The result of competitive binding experiment shows that DM binds more strongly to AT-rich DNA than NP does. These results provide bases for investigating the mechanism of interaction between the drugs and DNA and for improving the structure of target drug.
Antineoplastic Agents ; chemistry ; DNA ; chemistry ; Spectrometry, Mass, Electrospray Ionization ; methods

An HPLC-DAD-MS/MS method was developed for rapid analysis and identification of degradation products of buagafuran. Buagafuran and degradation products were separated on a Zorbax C8 column (5 microm, 4.6 mm x 150 mm) using acetonitrile-water (78 : 22) as mobile phase. The elutes were detected with diode array detector and tandem mass spectrometer via electrospray ionization source in positive ion mode. According to analysis of the retention time, UV spectra and MS, MS/MS data, combined with the possible degradation reaction of buagafuran, the structures of main degradation products were inferred. The results showed that six main degradation products were oxidation or peroxidation productions of buagafuran. Degradation product A was a double bond epoxidation product of buagafuran, degradation products B, C, D and E were the further oxidation products of degradation product A, degradation product F was a peroxidation product of buagafuran. The results indicated that the established method was effective in the rapid identification of the degradation products of buagafuran.
Chromatography, High Pressure Liquid ; methods ; Sesquiterpenes ; chemistry ; Spectrometry, Mass, Electrospray Ionization ; methods ; Tandem Mass Spectrometry ; methods

Phospholipids are key components of cellular membrane and signaling. Among cellular phospholipids, phosphoinositides, phosphorylated derivatives of phosphatidylinositol are important as a participant in essential metabolic processes in animals. However, due to its low abundance in cells and tissues, it is difficult to identify the composition of phosphoinositides. Recent advances in mass spectrometric techniques, combined with established separation methods, have allowed the rapid and sensitive detection and quantification of a variety of lipid species including phosphoinositides. In this mini review, we briefly introduce progress in profiling of cellular phosphoinositides using mass spectrometry. We also summarize current progress of matrices development for the analysis of cellular phospholipids using matrix-assisted laser desorption/ionization mass spectrometry. The phosphoinositides profiling and phospholipids imaging will help us to understand how they function in a biological system and will provide a powerful tool for elucidating the mechanism of diseases such as diabetes, cancer and neurodegenerative diseases. The investigation of cellular phospholipids including phosphoinositides using electrospray ionization mass spectrometry and matrix-assisted laser desorption/ionization mass spectrometry will suggest new insights on human diseases, and on clinical application through drug development of lipid related diseases.
Animals ; Humans ; Mass Spectrometry/*methods ; Phosphatidylinositols/*metabolism ; Phospholipids/*metabolism ; Spectrometry, Mass, Electrospray Ionization ; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

OBJECTIVETo investigate the monoterpene glycosides in Paeonia lactflora by UPLC-MS/MS.

METHODAn Acquity UPLC BEH C18 column (2.1 mm x 50 mm) with 1.7 microm particle size was used. The mobile phase was composed of acetonitrile and 0.1% formic acid in gradient mode. The flow rate was 0.4 mL x min and the chromatographic run time was 9 min for one run. The mass spectrometer equipped with an eletrospray ion source in negative ion mode.

RESULTSTotally six glycosides were analyzed and identified by the established UPLC-MS/MS method.

CONCLUSIONThe method was rapid, sensitive, and extremely useful for rapid identification of glycosides in P. lactiflora.

OBJECTIVES: To identify 1-(4-fluorophenyl)-2-(1-pyrrolidinyl) pentan-1-one (4-F-α-PVP) analog 1-(4-fluoro-3-methyl phenyl)-2-(1-pyrrolidinyl) pentan-1-one (4-F-3-Methyl-α-PVP) hydrochloride without reference substance. METHODS: The direct-injection electron ionization-mass spectrometry (EI-MS), GC-MS, electrospray ionization-high resolution mass spectrometry (ESI-HRMS), ultra-high performance liquid chromatography-high resolution tandem mass spectrometry (UPLC-HRMS/MS), nuclear magnetic resonance (NMR), ion chromatography and Fourier transform infrared spectroscopy (FTIR) were integrated utilized to achieve the structural analysis and characterization of the unknown compound in the sample, and the cleavage mechanism of the fragment ions was deduced by EI-MS and UPLC-HRMS/MS. RESULTS: By analyzing the direct-injection EI-MS, GC-MS, ESI-HRMS and UPLC-HRMS/MS of the compound in the samples, it was concluded that the unknown compound was a structural analog of 4-F-α-PVP, possibly with one more methyl group in the benzene ring. According to the analysis results of ¹H-NMR and ¹³C-NMR, it was further proved that the methyl group is located at the 3-position of the benzene ring. Since the actual number of hydrogen in ¹H-NMR analysis was one more than 4-F-3-Methyl-α-PVP neutral molecule, it was inferred that the compound existed in the form of salt. Ion chromatography analysis results showed that the compound contained chlorine anion (content 11.14%-11.16%), with the structural analysis of main functional group information by FTIR, the unknown compound was finally determined to be 4-F-3-Methyl-α-PVP hydrochloride. CONCLUSIONS A comprehensive method using EI-MS, GC-MS, ESI-HRMS, UPLC-HRMS/MS, NMR, ion chromatography and FTIR to identify 4-F-3-Methyl-α-PVP hydrochloride in samples is established, which will be helpful for the forensic science laboratory to identify this compound or other analog compounds.
Benzene ; Gas Chromatography-Mass Spectrometry/methods* ; Spectrometry, Mass, Electrospray Ionization ; Chromatography, High Pressure Liquid/methods*

A rapid ultra-performance liquid chromatography-electrospray ionization tandem mass spectrometric (UPLC-ESI-MS/MS) method is developed for the qualitative identification of constituents in the flower buds of seven Lonicera species. The optimal condition of separation and detection were achieved on an AcQuity UPLC BEH C18 column with a gradient elution with acetonitrile and 0.1% acetic acid within 17 min. Among the 33 constituents detected, 6 caffeoylquinic acids (including caffeic acid), 8 flavonoids and 8 iridoid glycosides were characterized based on their fragmentation patterns in collision-induced dissociation (CID) experiments and/or by comparison with standard compounds. In addition, to statistically establish the correlation and discrimination of the Lonicera species, principle component analysis (PCA) was applied in this study. Lonicera samples were divided into well-defined groups directly related to their species based on PCA in terms of the log transformed relative contents of the major caffeoylquinic acids (including caffeic acid) as the variables. All of results indicated that the method presented here is able to classify the sample species and to reveal characteristic details of the chemical constituents of different Lonicera species.
Chromatography, Liquid ; methods ; Flowers ; chemistry ; Lonicera ; chemistry ; classification ; Principal Component Analysis ; Spectrometry, Mass, Electrospray Ionization ; methods ; Tandem Mass Spectrometry ; methods

A quick HPLC-ESI-MS/MS method was established for simultaneous determination of three chemical compositions in Usnea, including usnic acid, diffractaic acid, and ramalic acid. The separation was performed on a chromatographic column of Agilent ZORBAX SB-C, (4.6 mm x 250 mm, 5 µm), and the mobile phase was methanol (0.05% formic acid)-0.05% formic acid solution (4 mmol ammonium acetate), with an isocratic elution at a flow rate of 0.8 ml · min⁻¹. Multiple reaction monitoring scanning mode (MRM) was performed combined with the ion switching technology in positive and negative ion switching mode to apply for the quantitative determination. The calibration curves for the above three compounds were linear in corresponding injection amount. Their average recoveries were 95.0%-105.1%, with RSDs of 1.1%-5.2%. The method was simple, rapid, accurate with high repeatability, which could provide a reference for overcalling evaluation the quality of Usnea.
Chromatography, High Pressure Liquid ; methods ; Hydroxybenzoates ; analysis ; Spectrometry, Mass, Electrospray Ionization ; methods ; Tandem Mass Spectrometry ; methods ; Usnea ; chemistry

A liquid chromatography coupled with diode array detector (DAD) and electrospray ionization time-of-flight mass spectrometry (ESI-TOF/MS) method was developed for the screening and identification of the multiple components in Tanreqing injection, a well-known Chinese medicine injection in China. By combining the DAD spectrum and the accurate mass measurement of ESI-TOF/MS, twelve components in Tanreqing injection were identified. This study contributes to clarifying the nature of Tanreqing injection, and provides an effective and reliable process for the comprehensive and systematic characterization of complex traditional Chinese medicine preparations.
Chromatography, High Pressure Liquid ; methods ; Drugs, Chinese Herbal ; chemistry ; Molecular Structure ; Spectrometry, Mass, Electrospray Ionization ; methods ; Tandem Mass Spectrometry ; methods

To characterize and identify multiple constituents in Danhong injection (DHI), a fast ultra-high performance liquid chromatography coupled to electrospray ionization quadrupole time-of-flight tandem mass spectrometry (UHPLC-ESI-QTOF/MS) method was established and validated in the present study. A total of 63 compounds, including 33 phenolic acids, 2 C-glycosyl quinochalcones, 6 flavonoid O-glycosides, 4 iridoid glycosides, 6 organic acids, 5 amino acids, and 3 nucleosides, were identified or tentatively characterized. In conclusion, the UHPLC-ESI-QTOF/MS method is useful and efficient for in-depth structural elucidation of chemical compounds in complex matrices of herbal medicines such as DHI.
Chromatography, High Pressure Liquid ; methods ; Drugs, Chinese Herbal ; chemistry ; isolation & purification ; Spectrometry, Mass, Electrospray Ionization ; methods ; Tandem Mass Spectrometry ; methods