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 Showing 1 - 46 of 46 Journals sorted alphabetically Accounts of Chemical Research       (Followers: 63) Acta Analytica       (Followers: 6) Advances in Analytical Chemistry       (Followers: 29) American Journal of Analytical Chemistry       (Followers: 31) Analitika i kontrol` (Analytics and control) Analytica Chimica Acta       (Followers: 43) Analytica Chimica Acta : X Analytical and Bioanalytical Chemistry       (Followers: 27) Analytical and Bioanalytical Chemistry Research       (Followers: 2) Analytical Chemistry       (Followers: 237) Analytical Chemistry Insights       (Followers: 21) Analytical Chemistry Letters       (Followers: 2) Analytical Letters       (Followers: 9) Annual Review of Analytical Chemistry       (Followers: 12) Chemical Data Collections Chinese Journal of Analytical Chemistry       (Followers: 5) Composites Communications       (Followers: 2) Comprehensive Analytical Chemistry       (Followers: 7) Critical Reviews in Analytical Chemistry       (Followers: 27) Current Analytical Chemistry       (Followers: 10) Drug Testing and Analysis       (Followers: 10) Electroanalysis       (Followers: 6) Field Analytical Chemistry and Technology       (Followers: 6) International Journal of Analytical Chemistry       (Followers: 21) International Journal of Environmental Analytical Chemistry       (Followers: 7) International Journal of Polymer Analysis and Characterization       (Followers: 8) Journal of Analysis and Testing Journal of Analytical Atomic Spectrometry       (Followers: 8) Journal of Analytical Chemistry       (Followers: 21) Journal of Electroanalytical Chemistry       (Followers: 7) Journal of Essential Oil Research       (Followers: 3) Journal of Progressive Research in Chemistry Journal of Radioanalytical and Nuclear Chemistry       (Followers: 7) Journal of Thermal Analysis and Calorimetry       (Followers: 24) Microchemical Journal       (Followers: 4) Nature Catalysis       (Followers: 6) Nigerian Journal of Chemical Research       (Followers: 1) Opflow       (Followers: 1) Pharmaceutical Analytical Chemistry: Open Access       (Followers: 1) Phytochemical Analysis       (Followers: 3) Polish Journal of Chemical Technology       (Followers: 1) Surface and Interface Analysis       (Followers: 15) TrAC Trends in Analytical Chemistry       (Followers: 46) Trends in Environmental Analytical Chemistry       (Followers: 3) Vibrational Spectroscopy       (Followers: 11) World Journal of Analytical Chemistry       (Followers: 3)
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 Journal of Analytical ChemistryJournal Prestige (SJR): 0.265 Citation Impact (citeScore): 1Number of Followers: 21      Hybrid journal (It can contain Open Access articles) ISSN (Print) 1608-3199 - ISSN (Online) 1061-9348 Published by Springer-Verlag  [2537 journals]
• Characteristics of a High-Resolution Mass Spectrum of an Adduct of
2-(Diethylamino)Ethylthiol with a Dipeptide (Cys–Pro)

PubDate: 2021-12-01

• New Mass Spectra: Electron Ionization Mass Spectra of Triclosan Acyl and
Silyl Derivatives

PubDate: 2021-12-01

• Supercritical Fluid Chromatography–Mass-Spectrometry of
Nitrogen-Containing Compounds: Atmospheric Pressure Ionization

Abstract: Supercritical fluid chromatography (SFC) in combination with mass spectrometry is a promising alternative to traditional chromatographic methods for the separation of polar nitrogen-containing compounds. The specificity of carbon dioxide-based mobile phases, used in this method, can affect the processes of the mass-spectrometric ionization of analytes and, as a consequence, the optimization strategy of the SFC–MS method. In this study, the effects of the composition of the CO2–methanol mobile phase, its flow rate, and also the parameters of the ion source (ESI capillary and corona discharge needle voltages, temperature) on the efficiency of ESI and APCI for a wide range of nitrogen-containing compounds from different classes were investigated. It was found that, because of the high basicity of the analytes under study, ESI in the positive ion mode is the preferred method of ionization, providing a multiple gain in efficiency compared to APCI for most analytes. An increase in the concentration of carbon dioxide in the mobile phase leads to a significant increase in the ESI efficiency and has a multidirectional effect on the ionization of analytes with different proton affinities under APCI conditions. An increase in APCI temperature leads to a decrease in the intensity of signals of protonated molecules and to the occurring of fragmentation processes regardless of the composition of the mobile phase for the vast majority of analytes.
PubDate: 2021-12-01

• Improvement of the Degradation Profiling of Eculizumab and Omalizumab
Monoclonal Antibodies by Liquid Chromatography–Mass Spectrometry

Abstract: The control of the degradation of monoclonal antibodies is one of primary steps of the biologics development process. Traditionally a range of chromatographic and electrophoretic procedures is used for this purpose. However, the most comprehensive information about the degradation process can be obtained using a multiple attribute method (MAM) approach based on bottom-up liquid chromatography–tandem mass spectrometry (LC–MS/MS). We perform a comparative evaluation of the forced degradation of omalizumab and eculizumab monoclonal antibodies obtained by the bottom-up approach, isoelectric focusing, and high-performance liquid chromatography. An advantage of HPLC–MS/MS in terms of dynamic range, specificity, and flexibility in the evaluation of degraded protein forms was demonstrated. The results show that the developed bottom-up approach can be used in the studies of the degradation of monoclonal antibodies and the routine biopharmaceutical quality control.
PubDate: 2021-12-01

• Study of Lignin by Atmospheric Pressure Photoionization Orbitrap Mass
Spectrometry: Effect of Spectral Resolution

Abstract: Atmospheric pressure photoionization Orbitrap mass spectrometry is a promising tool for studying lignin. It ensures the detection of thousands of lignin oligomers with molecular weights of up to 1.5–2 kDa and the reliable determination of their elemental compositions. In the present work, the effects of the resolving power of the mass analyzer on the recorded mass spectra of lignins and the results of characterization of the molecular composition of the biopolymer were studied. The test sample was a native dioxane lignin preparation, isolated from cedar wood. The phenomenon of the suppression of signals of lignin oligomers in the region of high molecular weights with an increase in the resolving power of the mass analyzer because of decay processes in the ion trap is described. It has been shown that a spectral resolution of at least 70 000 (M/ΔM, at m/z = 200) is required for screening purposes and the determination of the elemental compositions of low-molecular-weight lignin fractions. A detailed study of the molecular composition of lignin requires the use of spectral resolution of 280 000; it ensures a multiple increase in the number of detectable oligomers in the range of molecular weights above 1 kDa and also the reliable identification of signals of lignin–carbohydrate complexes.
PubDate: 2021-12-01

• Phytochemical Study of the Composition of the Unsaponifiable Fraction of
Various Vegetable Oils by Gas Chromatography–Mass Spectrometry

Abstract: We developed a method for quantitatively analyzing some components of the unsaponifiable fraction of edible oils and validated its characteristics. The component composition of the unsaponifiable fraction of 26 edible oil species was studied by gas chromatography/mass spectrometry. Squalene, sterols, and triterpene alcohols were quantified in oils using cholestenol as an internal standard. Some correlations were found between the structure of sterols and triterpene alcohols and their retention indices and electron impact fragmentation. More than 150 chemical compounds—unsaponifiable components—were identified. The method can be used to estimate the concentration of sterols, triterpene alcohols, and squalene in edible oils and determine the authenticity of oils by the characteristic profiles of the unsaponifiable fraction.
PubDate: 2021-12-01

• Detection of (Н2О $$)_{n}^{{ + \bullet }}$$ and Н+(Н2О)n Cluster Ions
Formed as a Result of Atmospheric Pressure Photoionization of Mixtures of
Water Vapor with Aromatic Hydrocarbons in Helium

PubDate: 2021-12-01

• Identification of Hydrocarbons Associated with Mumijo in the Tyva Republic
(Russia) by Gas Chromatography–Mass Spectrometry

Abstract: We studied the composition of hydrocarbons from a rock sample containing mumijo by gas chromatography–mass spectrometry. The electron ionization mass spectra and retention characteristics revealed the structure of the detected components. Long-chain n-alkanes C23–C29 and mono- and dimethylalkanes C28—C32 were identified in the extract. Hydrocarbons extracted from the mumijo-containing rock do not relate to hydrocarbons of oil, bitumen, coal, or oil shales. These hydrocarbons are in close association with mumijo formed during the aquatic transfer of biochemical components of small rodent excrements.
PubDate: 2021-12-01

• DART Mass Spectrometry in the Analysis of Organometallic Complexes

Abstract: We recorded and interpreted DART mass spectra of Hoveyda–Grubbs catalysts with N→Ru and S→Ru coordination bonds. The set of ions formed under DART ionization conditions is similar to those obtained using matrix-assisted laser desorption/ionization mass spectrometry. The optimal conditions (ionization gas, gas flow temperature) for recording DART mass spectra of the studied compounds were determined.
PubDate: 2021-12-01

• Correctness Criterion for Calculating Ion Trajectories in Edge Magnetic
Fields of Static Sector Mass Analyzers

Abstract: An objective criterion of the computation accuracy of ion trajectories aberration components in magnetic edge fields of static mass analyzers is derived.
PubDate: 2021-12-01

• Determination of Platinum and Rhodium by Stripping Voltammetry

Abstract: We studied the determination of platinum(IV) and rhodium(III) without separating them in solution by stripping voltammetry using the peak of the selective electrooxidation of lead from a lead–platinum–rhodium electrolytic deposit at a potential of –0.3 V. Lead, platinum, and rhodium were electrodeposited in situ on a graphite electrode surface from 1 M HCl. In an electrolytic deposit, platinum and rhodium did not form solid solutions but formed intermetallic compounds (IMCs) with lead. The selective electrooxidation of lead from the PtPb IMC and rhodium from the Pb2Rh IMC occurred at –0.3 V. Platinum(IV) and rhodium(III) can be determined without separation using the standard addition method. The lower limit of determination for platinum(IV) by the peak of the selective electrooxidation of lead from the PbPt IMC is 0.86 mg/L. The lower limit of determination for rhodium(III) by the peak of the selective electrooxidation of lead from the Pb2Rh IMC is 0.0046 mg/L.
PubDate: 2021-12-01

• Memory Effect as a Source of Abnormal Uncertainty in the Sr Isotope
Analysis by the Double Spike Technique

Abstract: This article discusses the reasons for the poor reproducibility of the 44Ca/42Ca and 88Sr/86Sr isotope ratios measured by double spike isotope dilution techniques. It was found that the heterogeneous evaporation of a sample from an ion source filament is not the main reason for the poor reproducibility. It was demonstrated that the observed discrepancy between the predicted and experimental data can be explained by the memory effect rather than by the heterogeneous evaporation effect. The similarities between these effects, occurring in thermal ionization ion sources, were discussed as well. It was shown that the replacement of a single-filament ion source with a double-filament source ensures a decrease in the memory effect and the improvement of the precision of the 88Sr/86Sr measurement by a factor of more than two: from ±0.037‰ to ±0.013‰. At the same time, the measured values of 87Sr/86Sr in SRM987 were always within the 0.710250 ± 0.000009 value.
PubDate: 2021-12-01

• Development of a Surface Ionization Mass Spectrometry Method for the
Highly Sensitive and Highly Selective Analysis of Morphine in Biofluid

Abstract: A method of surface ionization mass spectrometry is developed for the direct detection and analysis of morphine in biofluid. Morphine mixed with human blood is studied for the first time using this method without its preliminary chromatographic separation and extraction. The mechanism of the ionization of a mixture of morphine in biofluids is consistent with the previously established regularities of the surface ionization of nitrogen-containing compounds. The limit of detection for morphine mixed with blood by the method was tens of picograms with a linear range of more than two orders of magnitude. It was shown that because of the high selectivity of the method, such a complex sample can be analyzed without its preliminary chromatographic separation and extraction, which will significantly reduce the time of analysis of the sample, and also, because of the high sensitivity of the method, reduce false negative results.
PubDate: 2021-12-01

• Possibilities and Limitations of Solid-Phase and Liquid Extraction for the
Determination of Polycyclic Aromatic Hydrocarbons in Environmental Samples

Abstract: The review systematizes data on various extraction techniques for sample preparation in the determination of polycyclic aromatic hydrocarbons (PAHs) in environmental samples, provides a classification, and describes the capabilities of these techniques. The main versions and methods of solid-phase extraction (SPE) and liquid–liquid (LLE) extraction of structurally different PAHs from complex multicomponent systems are discussed. The variety of SPE and LLE methods, the peculiarities of their combinations with other methods, and the advantages and disadvantages of each sample preparation method are demonstrated. Chromatographic methods are preferred for detection after the solid-phase or liquid–liquid extraction of PAHs from environmental samples.
PubDate: 2021-12-01

• Method Development and Validation for Quantification of Trace Elements in
Aluminous Ore (Bauxite) Using Inductively Coupled Plasma–Optical
Emission Spectrometry

Abstract: An inductively coupled plasma-optical emission spectrometric method for the determination of trace elements, i.e., calcium, gallium, phosphorous and vanadium in bauxite samples has been developed. The developed method was validated by determining several validation parameters which included linear range, limits of detection and quantification, precision, and accuracy. The method was found to be linear in the range of 0.01–0.25% for V2O5 and P2O5, 0.001–0.01% for Ga2O3, and 0.01–2% for CaO with the coefficient of determination (R2) obtained for these regressions higher than 0.990. The percentage recoveries of bauxite reference standard and spiked samples ranged from 90 to 99%. The detection limit values for Ca, V, P, and Ga were found to be 0.001, 0.0004, 0.003, and 0.002 mg/L, respectively, while the limits of quantification were 0.002, 0.001, 0.009, and 0.006 mg/L, respectively. The validated method was found to be rapid and reliable within the acceptable limit for the simultaneous determination of bauxite constituents, i.e., P, V, Ga, and Ca, and applicable for routine analyses in the laboratories.
PubDate: 2021-12-01

• A New Approach to the Mass Spectrometric Analysis of Aqueous Electrolyte
Solutions Using a Gas-Dynamic Interface with a Gas Jet at the Inlet of a
Time-of-Flight Mass Spectrometer with Orthogonal Ion Injection

Abstract: We report the results of a study of the effect of a supersonic gas jet on the formation and extraction of analyzed ions from a liquid supplied through a capillary to an RF quadrupole connected to a time-of-flight mass spectrometer with orthogonal ion injection. The supersonic gas jet is formed inside a cylindrical channel and passes through an electron ionization ion source. The results confirm the prospects of using a supersonic jet to creating a high-performance ion source from a liquid supplied to the vacuum region under the pressure of ~10–4 Torr.
PubDate: 2021-12-01

• Analysis of Cerium Oxide by Mass Spectrometry and Optical Emission
Spectrometry with Inductively Coupled Plasma

Abstract: Procedures are developed for the multielement analysis of high-purity cerium oxide for the manufacture of phosphors and optical materials using inductively coupled plasma–mass spectrometry (ICP–MS) and inductively coupled plasma–optical emission spectrometry (ICP–OES). The “robust” settings of the mass spectrometer are given suitable to determine Fe, Ni, Cr, Co, Cu, V, Mn, and rare-earth metals in cerium oxide (nebulizer gas flow, liquid flow, plasma sampling depth, the extract lens voltage), lowering the matrix effect and, therefore, enabling the use of more concentrated solutions for analysis. The effect of the matrix element in the direct analysis of cerium oxide by ICP–OES is estimated. The combination of mass spectral and atomic emission methods has some advantages, expands the range of elements to be determined, and increases the reliability of the analysis. In particular, the use of ICP–OES makes it possible to determine low concentrations of terbium in cerium oxide (the limit of determination for terbium by ICP–OES is 1 × 10–4 wt %) and decreases the limits of determination for Fe and Pr by a factor of 4–5 compared to ICP–MS. The limits of determination of the target components (Fe, Ni, Cr, Co, Cu, V, Mn, and rare-earth metals) in cerium oxide by ICP–MS and ICP–OES are in the range of n × 10–6– n × 10–4 wt %.
PubDate: 2021-12-01

• A Molecularly Imprinted Polymer as the Adsorbent for the Selective
Determination of Oxazepam in Urine and Plasma Samples by High-Performance
Liquid Chromatography with Diode Array Detection

Abstract: Molecularly imprinted polymer for the selective adsorption of oxazepam was synthesized using precipitation polymerization in the presence of oxazepam as a template, ethylene glycol dimethacrylate as a crosslinking agent, methacrylic acid as a functional monomer and 2,2-azobisisobutyronitrile as an initiator. The polymer was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy and thermogravimetric analysis. The obtained molecular imprinting polymer showed high affinity to template molecule and was used as a selective sorbent for selective extraction of oxazepam from human urine and plasma samples. Good linearity was obtained for the analyte in the range of 2.0–600 µg/L with relative standard deviation ≤ 4.0%. Under optimal conditions, maximum adsorption capacity obtained was 136 mg/g. The detection limit of the proposed procedure was 0.5 µg/L. Finally, this method was applied to the determination of oxazepam in plasma and urine samples and satisfactory results were achieved.
PubDate: 2021-12-01

• An Electrochemical Approach to As(V) Determination via an Interaction with
Alizarin Red S in Aqueous Medium

Abstract: Electrochemically inactive As(V) was detected by estimating the interactions between Alizarin Red S (ARS) and $${\text{AsO}}_{4}^{{3 - }}$$ ions in aqueous medium. From the cyclic voltammetry, it was confirmed that the addition of As(V) reduces the diffusion coefficient of the ARS molecule towards the electrode surface. The experimental results revealed that the diffusion coefficient of ARS was 1.476 × 10−5 cm2/s which decreased to 1.02 × 10−5 cm2/s in the presence of $${\text{AsO}}_{4}^{{3 - }}$$ ions in the solution. Measurements of electrochemical impedance spectroscopy (EIS) were also carried out, and an upward pattern of charge transfer resistance (Rct) was found with an increase in As(V) concentration. The EIS technique gave a linear relationship in terms of Rct vs. As(V) concentration. Hence, it was concluded that this technique could be utilized in the electrochemical detection of As(V). The developed method for the detection of As(V) has exhibited excellent sensitivity (74 Ω/µM), low detection limit (14.2 ± 0.1 ppb at S/N of 3), and remarkable repeatability.
PubDate: 2021-12-01

• Peculiarities of 2,6-Di-tert-butylpyridine Protonation: Mobility of
Protonated Molecules

Abstract: 2,6-Di-tert-butylpyridine (DTBP) is widely used in ion mobility spectrometry and its combination with mass spectrometry as a standard compound for the calibration of the ion mobility scale. In this work, we computed the structure and determined the conformational composition of DTBP and products of its protonation using quantum chemical methods. We found three conformers of DTBP with similar stabilities. We showed that their protonation leads to three products with similar stabilities. The proton affinity and ga--s-phase basicity of DTBP were calculated. The thermodynamic parameters of DTBP reactions with hydrated hydroxonium ions H3O+(H2O)n (n = 0–3) were computed. The calculations confirmed that, in agreement with the experimental data, the reactions lead to the formation of protonated DTBP molecules that are not hydrated and do not form proton-bound dimers. We showed that the peculiarities of DTBP protonation are substantially due to the steric effect of tert-butyl groups. The reduced mobility of protonated DTBP molecules was calculated by the trajectory method. The calculation error is close to the experimental one. According to the experimental data, the calculated reduced mobilities do not significantly change with temperature.
PubDate: 2021-12-01

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