Rapid screening and determination of designer drugs in saliva by a nib‐assisted paper spray‐mass spectrometry and separation technique

A method for the rapid screening and determination of amphetamine‐type designer drugs in saliva by a novel nib‐assisted paper spray‐mass spectrometry procedure is described. Under optimized conditions, the limit of detections for amphetamine derivatives (model samples: o‐, m‐, p‐chloroamphetamine and o‐, m‐, p‐fluoroamphetamine, respectively) were determined to 0.1 μg/mL by the nib‐assisted paper spray‐mass spectrometry method. This method is easier and has a higher sensitivity than similar methodologies, including atmospheric pressure/matrix‐assisted laser desorption ionization mass spectrometry and electrospray‐assisted laser desorption ionization/mass spectrometry. Data obtained using more classical separation methods, including liquid chromatography and capillary electrophoresis, are also reported.     

Mass spectrometric analysis of ceramic components for solid oxide fuel cells

For the determination of trace impurities in ceramic components of solid oxide fuel cells (SOFCs), some mass spectrometric methods have been applied such as spark source mass spectrometry (SSMS), laser ionization mass spectrometry (LIMS), laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) and inductively coupled plasma mass spectrometry (ICP-MS). Due to a lack of suitable standard reference materials for quantifying of analytical results on La _x Sr _y MnO₃ cathode material a matrix-matched synthetic standard-high purity initial compounds doped with trace elements-was prepared in order to determine the relative sensitivity coefficients in SSMS and LA-ICP-MS. Radiofrequency glow discharge mass spectrometry (rf-GDMS) was developed for trace analysis and depth profiling of thick non-conducting layers. Surface analytical techniques, such as secondary ion mass spectrometry (SIMS) and sputtered neutral mass spectrometry (SNMS), were used to determine the element distribution on surfaces (homogeneity) and the surface contaminants of SOFC ceramic layers.Dedicated to Professor Dr. rer. nat. Hubertus Nickel on the occasion of his 65th birthday     

Chemometrics comparison of gas chromatography with mass spectrometry and comprehensive two‐dimensional gas chromatography with time‐of‐flight mass spectrometry Daphnia magna metabolic profiles exposed to salinity

The performances of gas chromatography with mass spectrometry and of comprehensive two‐dimensional gas chromatography with time‐of‐flight mass spectrometry are examined through the comparison of Daphnia magna metabolic profiles. Gas chromatography with mass spectrometry and comprehensive two‐dimensional gas chromatography with mass spectrometry were used to compare the concentration changes of metabolites under saline conditions. In this regard, a chemometric strategy based on wavelet compression and multivariate curve resolution–alternating least squares is used to compare the performances of gas chromatography with mass spectrometry and comprehensive two‐dimensional gas chromatography with time‐of‐flight mass spectrometry for the untargeted metabolic profiling of Daphnia magna in control and salinity‐exposed samples. Examination of the results confirmed the outperformance of comprehensive two‐dimensional gas chromatography with time‐of‐flight mass spectrometry over gas chromatography with mass spectrometry for the detection of metabolites in D. magna samples. The peak areas of multivariate curve resolution–alternating least squares resolved elution profiles in every sample analyzed by comprehensive two‐dimensional gas chromatography with time‐of‐flight mass spectrometry were arranged in a new data matrix that was then modeled by partial least squares discriminant analysis. The control and salt‐exposed daphnids samples were discriminated and the most relevant metabolites were estimated using variable importance in projection and selectivity ratio values. Salinity de‐regulated 18 metabolites from metabolic pathways involved in protein translation, transmembrane cell transport, carbon metabolism, secondary metabolism, glycolysis, and osmoregulation.     

Study on chemical constituents and fingerprints of Phellodendron amurense Rupr. based on ultra-performance liquid chromatography–quadrupole–time-of-flight–mass spectrometry

The chemical constituents from Phellodendron amurense Rupr. were characterized systematically by ultra-performance liquid chromatography—quadrupole–time-of-flight–mass spectrometry method for collecting mass spectrometry data, and the fingerprints method was established, providing reference for its quality control. The chromatographic column was ACQUITY UPLC BEH-C₁₈ (100 mm×2.1 mm, 1.7 μm). The mobile phase was acetonitrile-0.1% formic acid aqueous solution and the compounds from P. amurense Rupr. were identified by Qualitative Analysis 10.0 software, reference substance, retention time, mass spectrometry fragmentation pattern and database retrieval. Meanwhile, liquid chromatography–mass spectrometry fingerprint methods of P. amurense Rupr. and Phellodendron chinense Schneid. were established by using the similarity evaluation system of chromatographic fingerprint of traditional Chinese medicine (2012 edition), and the differences were analyzed by multivariate statistical analysis methods. A total of 105 compounds were identified, including 102 alkaloids, two phenolic acids, and one lactone compound. Liquid chromatography–mass spectrometry fingerprint method was established with ideal precision, stability and repeatability, and 12 quality differential markers were recognized between the above two herbs. Liquid chromatography–mass spectrometry method can be used for qualitative analysis of the constituents of Phellodendron amurense Rupr., providing reference for clarifying the material basis and promoting the clinical precision medication and quality evaluation of P. amurense Rupr.     

Differentiation of isomeric 5- and 7-oxo derivatives of tetrahydrothiazolo[3,2-a]pyrimidine by electron impact mass spectrometry

The electron impact mass spectra of two series of 5-oxo-tetrahydro-5H-thiazolo [3,2-a]pyrimidine-6-ethylcarboxylates and 7-oxo-tetrahydro-7H-thiazolo [3,2-a]pyrimidine-6-ethylcarboxylates were measured and fragmentation patterns examined. Structures were assigned from analysis of oxo molecular ion fragmentations. Compounds of the 5-oxo series gave an [M – CO₂C₂H₅]⁺ fragmentation whereas compounds of the 7-oxo series gave three characteristic cleavages. This decomposition was confirmed for one pair of isomers by high-resolution mass spectrometry and unimolecular mass-analysed ion kinetic energy spectrometry. Electron impact mass spectrometry is a convenient method for assigning structures of 5- and 7-oxo regioisomers of tetrahydrothiazolo[3,2-a]pyrimidine-6-carboxylates.     

Liquid chromatography–tandem mass spectrometry of porphyrins and porphyrinogens in biological materials: separation and identification of interfering poly(ethylene) glycol by travelling wave ion mobility spectrometry/tandem mass spectrometry

Biological and clinical samples for porphyrin and porphyrinogen analyses by liquid chromatography–tandem mass spectrometry (LC‐MS/MS) are often contaminated with poly(ethylene)glycol (PEG), which complicates the interpretation of mass spectra and characterisation of new porphyrin metabolites. Two contaminating PEG molecules (m/z 833 and m/z 835) were completely separated from uroporphyrin I (m/z 831) by travelling wave ion mobility spectrometry and characterised by tandem mass spectrometry. One of the PEG species (m/z 835) also co‐eluted with uroporphyrinogen I (m/z 837) and was unresolvable by travelling wave ion mobility spectrometry/MS, therefore contaminating the MS/MS mass spectra owing to isotope distribution. These PEG species, with the [M + H]⁺ ions at m/z at 833 and/or m/z 835, co‐eluted with uroporphyrin I and uroporphyrinogen I by LC‐MS/MS and could be wrongly identified as uroporphomethenes. Copyright © 2013 John Wiley & Sons, Ltd.     

Identification and metabolite profiling of alkaloids in aerial parts of Papaver rhoeas by liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry

Papaver plants can produce diverse bioactive alkaloids. Papaver rhoeas Linnaeus (common poppy or corn poppy) is an annual flowering medicinal plant used for treating cough, sleep disorder, and as a sedative, pain reliever, and food. It contains various powerful alkaloids like rhoeadine, benzylisoquinoline, and proaporphine. To investigate and identify alkaloids in the aerial parts of P. rhoeas, samples were collected at different growth stages and analyzed using liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry. A liquid chromatography with mass spectrometry method was developed for the identification and metabolite profiling of alkaloids for P. rhoeas by comparing with Papaver somniferum. Eighteen alkaloids involved in benzylisoquinoline alkaloid biosynthesis were used to optimize the liquid chromatography gradient and mass spectrometry conditions. Fifty‐five alkaloids, including protoberberine, benzylisoquinoline, aporphine, benzophenanthridine, and rhoeadine‐type alkaloids, were identified authentically or tentatively by liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry in samples taken during various growth stages. Rhoeadine alkaloids were observed only in P. rhoeas samples, and codeine and morphine were tentatively identified in P. somniferum. The liquid chromatography coupled with quadrupole time‐of‐flight tandem mass spectrometry method can be a powerful tool for the identification of diverse metabolites in the genus Papaver. These results may help understand the biosynthesis of alkaloids in P. rhoeas and evaluate the quality of this plant for possible medicinal applications.     

Rapid discovery of absorbed constituents and metabolites in rat plasma after the oral administration of Zi Shen Wan using high‐throughput UHPLC–MS with a multivariate analysis approach

Zi Shen Wan is a typical formula consisting of three herbs, Phellodendri Amurensis Cortex, Rhizoma Anemarrhenae, and Cortex Cinnamomi, and has been widely used for treating prostatitis and infection diseases. However, it lacks in‐depth research of the constituents of Zi Shen Wan in vivo and in vitro. In this work, ultra high performance liquid chromatography coupled with quadrupole‐time‐of‐flight mass spectrometry and MassLynx software was established to characterize the chemical compositions of Zi Shen Wan in vivo and in vitro. In total, 92 peaks were characterized in vitro and 33 peaks were characterized in vivo based on mass spectrometry and tandem mass spectrometry data. Among the 33 compounds characterized in rat plasma, 22 prototype components absorbed in rat serum and 11 metabolites were identified in vivo. This work was fully reports the chemical constituents of traditional Chinese formula of Zi Shen Wan, it demonstrated that ultra high performance liquid chromatography combined with quadrupole time‐of‐flight mass spectrometry coupled to MassLynx software and multivariate data processing approach could be successfully applied for rapid screening and comprehensive analysis of chemical constituents in vitro and prototype components or metabolites in vivo of traditional Chinese medicine.     

Analysis of the volatile oil from the stem of Acanthopanax Senticosus (Rupr. et Maxim.) harms with several hyphenated methods of chromatography

Gas chromatography/quadrupole mass spectrometry (GC/qMS), gas chromatography/Fourier transform infrared spectrometry (GC/FTIR) and gas chromatography/orthogonal acceleration time-of-flight mass spectrometry (GC/oaTOFMS) were applied to analyze the volatile oil from the stem of Acanthopanax Senticosus (Rupr. et Maxim.) Harms. Based on the mass spectra search function of GC/qMS with the aid of the discriminability of the geometrical isomer by GC/FTIR and the ability to determine the accurate mass charge ratio (m/z) by GC/oaTOFMS, 68 GC eluants were identified successfully. Compared with the results obtained by GC/qMS only, the analytical results obtained by these hyphenated methods of gas chromatography are more credible. __________ Translated from Chinese Journal of Chromatography, 2005, 23(2)(in Chinese)     

Synthesis and Electrospray Ionization Mass Spectra of N-（1,3, 2-Dioxaphosphorinan-2-ylmethyl）thiophosphoramidates

N-（1,3,2-Dioxaphosphorinan-2-ylmethyl）thiophosphoramidates were synthesized and determined by NMR spectra and positive ion electrospray ionization mass spectrometry （ESI-MS） in conjunction with tandem mass spectrometry （MS/MS）. The fragmentation pathways were investigated. The results show that these characteristic ions in ESI mass spectra are useful in the structural determination of N-（1,3,2-dioxaphosphorinan-2-ylmethyl）- thiophosphoramidates.     

Identification of Antifungal Peptides from Bacillus subtilis BS-918

Bacillus subtilis BS-918 shows strong activity against a broad spectrum of plant and postharvest pathogenic fungi. Antifungal compounds produced by BS-918 were isolated by extraction and gel chromatography, and structural identification was performed by electrospray ionization coupled with collision induced dissociation mass spectrometry. Two kinds of precursor ions belonging to iturin and fengycin were revealed. The first precursor ion at m/z 1071.7 was analyzed by collision induced dissociation mass spectrometry and was identified to be iturin A with a C₁₆ β-amino fatty acid chain. Collision induced dissociation mass spectrometry of the second precursor showed the presence of two fengycins. Ions at m/z 1449.5 and m/z 1463.9 were identified to homologs of fengycin A with C₁₅ and C₁₆ β-hydroxy fatty acid chains, whereas ions at m/z 1477.8 and m/z 1491.9 were homologs of fengycin B with C₁₅ and C₁₆ fatty acid chains.     

Rapid separation and identification of furocoumarins in Angelica dahurica by high‐performance liquid chromatography with diode‐array detection,time‐of‐flight mass spectrometry and quadrupole ion trap mass spectrometry

High‐performance liquid chromatography with diode‐array detection (HPLC/DAD), time‐of‐flight mass spectrometry (HPLC/TOFMS) and quadrupole ion trap mass spectrometry (HPLC/QITMS) were used for separation, identification and structural analysis of furocoumarins in Angelica dahurica. Two furocoumarins (imperatorin and isoimperatorin) in Angelica dahurica extract were identified unambiguously by comparing their relative retention times, characteristic ultraviolet information and accurate mass measurement. A formula database of known furocoumarins in Angelica dahurica was established, against which the other 21 furocoumarins were identified effectively based on the accurate extract masses and formulae acquired by HPLC/TOFMS. In order to distinguish the isomers, multi‐stage mass spectrometry (MSⁿ, ion trap mass spectrometry) was used. General fragmentation behavior of the furocoumarins in the ion trap mass spectrometer was studied by the two furocoumarin standards, and their fragmentation rules in MSⁿ spectra were summarized. These deduced fragmentation rules of furocoumarins were successfully implemented in distinguishing the three groups of isomers in Angelica dahurica by HPLC/QITMS. By using the three different analytical techniques, 23 furocoumarins in Angelica dahurica were tentatively identified within 30 min. Finally, HPLC/TOFMS fingerprints of Angelica dahurica were established by which it can be concluded that a rapid and effective method based on the three analytical techniques for identification of chemical components was established. This can provide help for further quality control of Angelica dahurica and pharmacology mechanism study of furocoumarins in Angelica dahurica. Copyright © 2009 John Wiley & Sons, Ltd.     

Differentiation of lisinopril and its RSS diastereomer by liquid chromatography combined with collision‐induced dissociation mass spectrometry

A simple and sensitive liquid chromatography tandem multiple‐stage mass spectrometry (HPLC/MS/MS) method suitable for bulk lisinopril analysis was developed, by which lisinopril and its RSS isomer were separated and differentiated. In the collision‐induced dissociation (CID) mass spectra of the [M + H]⁺ ions, the abundance of the fragment ion of m/z 246 for lisinopril was about two times higher than the ion of m/z 245; however, the former fragment ion was noted to be a little lower than the latter for RSS isomer at all collision energies. In the CID mass spectra of the [M + Li]⁺ ion, the abundance of the rearrangement ion of m/z 315 for the RSS isomer was about three times higher than that for lisinopril. Furthermore, the difference was supported by the results of energy‐resolved mass spectrometry (ERMS) in the test range of collision energies. Similar differences were also observed between the CID mass spectra of lisinopril and RSS isomer methylester, which indicated that the RSS isomer could be rapidly characterized by the CID mass spectra of both the protonated and lithium adduct ion. Elemental compositions of all the ions were confirmed by Fourier Transform ion cyclotron resonance ESI mass spectrometry (FT‐ICR‐ESI/MS). In addition, theoretical computations were carried out to support the experimental results. Copyright © 2009 John Wiley & Sons, Ltd.     

Unusual behavior of pyrazolo[1,2-a]pyrazoles in fast atom bombardment (fab) and frit-fast atom bombardment (Frit-FAB) mass spectrometry. Influence of the matrix

The nature of the matrix used in Fast Atom Bombardment (FAB) mass spectrometry analyses of pyrazolo[1,2-a]pyrazoles was found to influence significantly their positive and negative ions mass spectra. Indeed the use of glycerol provided an abundant ion corresponding to the protonated molecule (M+H)⁺ whereas the meta-nitrobenzyl alcohol favored the formation of the radical ion M^+°. Such results which are in accordance with the oxidoreduction properties of the matrices studied were also established in Frit-FAB mass spectrometry analyses of pyrazolo[1,2-a]pyrazoles.     

Analysis of xanthates by negative-ion fast atom bombardment mass spectrometry

A new technique using negative-ion fast atom bombardment mass spectrometry for the analysis of xanthates and related compounds is described. Electron impact and positive-ion fast atom bombardment mass spectrometry produced no structurally related fragment ions or observable molecular ions at the expected m/z values. It was demonstrated that negative-ion fast atom bombardment ionization was the most suitable method of ionization for structure elucidation studies for the compounds described.     

Characterization of blocked nucleosides by mass spectrometry. Benzyl derivatives

The mass spectra of eleven model monobenzylated nucleosides were studied using low and high resolution mass spectrometry. Structural assignments to the major ions were made and several decomposition mechanisms proposed, with the goal of establishing the uses and limitations of mass spectrometry for the characterization of benzylaled nucleosides. Mass spectra generally permit determination of the extent and site of benzylation, with particular regard to base vs. sugar substitution, 0–2′ vs. 0–3′ or 0–5′, and in some cases 0–5′ vs. other isomers.     

Biomarker Candidates of <Emphasis Type="Italic">Chlamydophila pneumoniae</Emphasis> Proteins and Protein Fragments Identified by Affinity-Proteomics Using FTICR-MS and LC-MS/MS

We report here an affinity-proteomics approach that combines 2D-gel electrophoresis and immunoblotting with high performance mass spectrometry to the identification of both full length protein antigens and antigenic fragments of Chlamydophila pneumoniae (C. pneumoniae). The present affinity-mass spectrometry approach effectively utilized high resolution FTICR mass spectrometry and LC-tandem-MS for protein identification, and enabled the identification of several new highly antigenic C. pneumoniae proteins that were not hitherto reported or previously detected only in other Chlamydia species, such as Chlamydia trachomatis. Moreover, high resolution affinity-MS provided the identification of several neo-antigenic protein fragments containing N- and C-terminal, and central domains such as fragments of the membrane protein Pmp21 and the secreted chlamydial proteasome-like factor (Cpaf), representing specific biomarker candidates.     

Mass spectrometry in structural and stereochemical problems. Part CLIII. Electron impact-promoted fragmentation of n-alkyl cyanides

In spite of previous extensive studies on the mass spectrometry of alkyl cyanides, no good mechanistic insight has as yet been gained into the behavior of straight chain alky1 cyanides. For this reason the possible origins for the principal ions in the mass spectrum of a typical alkyl cyanide (n-hexyl cyanide) have been determined using high resolution mass spectrometry anddeuterium labeling of every carbon atom. The results lead to the conclusion that most of the typical fragmentation processes of n-alkyl cyanides proceed through cyclic intermediates.     

Pyrolysis/gas chromatography/mass spectrometry of asphaltene fractions

Two n-heptane-precipitated asphaltene samples, characterized by elemental analysis and nuclear magnetic resonance spectrometry, were fractionated according to relative molecular size by gel permeation chromatography (GPC). Both the whole asphaltene samples and their fractions were analysed by pyrolysis/gas chromatography/mass spectrometry. The data obtained from the pyrograms (average side-chain length, aromaticity index, sulphur compounds vs. aliphatic compounds, presence of SO₂ and CO₂) demonstrated that, in the case of asphaltenes, GPC fractionation results in the separation of different chemical structures ranging from lower molecular mass, highly aromatic and polar compounds to higher molecular mass, less polar and aromatic compounds.     

Investigation and analysis of Ryukyu lacquerwares decorated with wisteria vine by pyrolysis GC/MS and 87Sr/86Sr isotope ratio

Three lacquer trays decorated with wisteria vine (rattan) produced in the 18–19th century in Ryukyu Kingdom were analyzed by cross‐section, pyrolysis gas chromatography/mass spectrometry, strontium isotope ratios (⁸⁷Sr/⁸⁶Sr), radioactive carbon‐14 dating, and field emission scanning electron microscope with energy dispersive X‐ray spectrometry. One sample had only one red lacquer layer, and the other two samples had two layers with top red lacquer and a bottom layer of natural lacquer, respectively. The ⁸⁷Sr/⁸⁶Sr isotope ratios of three samples were 0.7091–0.7107, consistent with that of the Japanese mainland (<0.7110). The wood species of lacquer objects were identified as Japanese white pine, Japanese cedar, and Cunninghamia lanceolata, which grow in the Japanese islands. The carbon‐14 dating results showed that the lacquer films were about 1719–1785. In pyrolysis gas chromatography/mass spectrometry, 3‐heptylphenol (C7) and 3‐pentadecylphenol (C15) were detected in the mass chromatograms at m/z = 108 and palmitic acid and stearic acid were detected in the mass chromatograms at m/z = 60, implying that the coating material was sap collected from Toxicodendron vernicifluum lacquer tree and included a drying oil. Energy dispersive X‐ray spectrometry revealed that mainly mercury sulfide was used as red pigment in these three Ryukyu lacquerwares. Copyright © 2017 John Wiley & Sons, Ltd.