Subjects -> CHEMISTRY (Total: 986 journals)
    - ANALYTICAL CHEMISTRY (58 journals)
    - CHEMISTRY (715 journals)
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    - ELECTROCHEMISTRY (28 journals)
    - INORGANIC CHEMISTRY (44 journals)
    - ORGANIC CHEMISTRY (48 journals)
    - PHYSICAL CHEMISTRY (71 journals)

CHEMISTRY (715 journals)                  1 2 3 4 | Last

Showing 1 - 200 of 735 Journals sorted alphabetically
2D Materials     Hybrid Journal   (Followers: 19)
Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement     Hybrid Journal   (Followers: 34)
ACS Applied Polymer Materials     Hybrid Journal   (Followers: 2)
ACS Catalysis     Hybrid Journal   (Followers: 60)
ACS Chemical Neuroscience     Hybrid Journal   (Followers: 23)
ACS Combinatorial Science     Hybrid Journal   (Followers: 23)
ACS Macro Letters     Hybrid Journal   (Followers: 30)
ACS Medicinal Chemistry Letters     Hybrid Journal   (Followers: 48)
ACS Nano     Hybrid Journal   (Followers: 414)
ACS Photonics     Hybrid Journal   (Followers: 17)
ACS Symposium Series     Full-text available via subscription   (Followers: 3)
ACS Synthetic Biology     Hybrid Journal   (Followers: 31)
Acta Chemica Iasi     Open Access   (Followers: 8)
Acta Chimica Slovaca     Open Access   (Followers: 4)
Acta Chimica Slovenica     Open Access   (Followers: 2)
Acta Chromatographica     Full-text available via subscription   (Followers: 9)
Acta Facultatis Medicae Naissensis     Open Access   (Followers: 1)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 9)
Acta Scientifica Naturalis     Open Access   (Followers: 3)
adhäsion KLEBEN & DICHTEN     Hybrid Journal   (Followers: 9)
Adhesion Adhesives & Sealants     Hybrid Journal   (Followers: 11)
Adsorption Science & Technology     Open Access   (Followers: 8)
Advanced Electronic Materials     Hybrid Journal   (Followers: 3)
Advanced Functional Materials     Hybrid Journal   (Followers: 72)
Advanced Science Focus     Free   (Followers: 6)
Advanced Theory and Simulations     Hybrid Journal   (Followers: 1)
Advanced Therapeutics     Hybrid Journal   (Followers: 1)
Advances in Chemical Engineering and Science     Open Access   (Followers: 94)
Advances in Chemical Science     Open Access   (Followers: 37)
Advances in Chemistry     Open Access   (Followers: 31)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 21)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Environmental Chemistry     Open Access   (Followers: 10)
Advances in Enzyme Research     Open Access   (Followers: 12)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11)
Advances in Materials Physics and Chemistry     Open Access   (Followers: 31)
Advances in Nanoparticles     Open Access   (Followers: 19)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Polymer Science     Hybrid Journal   (Followers: 49)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 19)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 7)
Advances in Science and Technology     Full-text available via subscription   (Followers: 15)
Aerosol Science and Engineering     Hybrid Journal  
African Journal of Bacteriology Research     Open Access  
African Journal of Chemical Education     Open Access   (Followers: 5)
African Journal of Pure and Applied Chemistry     Open Access   (Followers: 7)
Agrokémia és Talajtan     Full-text available via subscription   (Followers: 2)
Al-Kimia : Jurnal Penelitian Sains Kimia     Open Access  
Alchemy : Journal of Chemistry     Open Access   (Followers: 4)
Alchemy : Jurnal Penelitian Kimia     Open Access   (Followers: 2)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Alotrop     Open Access  
AMB Express     Open Access   (Followers: 1)
Ambix     Hybrid Journal   (Followers: 3)
American Journal of Biochemistry and Biotechnology     Open Access   (Followers: 69)
American Journal of Biochemistry and Molecular Biology     Open Access   (Followers: 22)
American Journal of Chemistry     Open Access   (Followers: 36)
American Journal of Plant Physiology     Open Access   (Followers: 13)
American Mineralogist     Hybrid Journal   (Followers: 15)
Anadolu University Journal of Science and Technology A : Applied Sciences and Engineering     Open Access  
Analyst     Full-text available via subscription   (Followers: 37)
Angewandte Chemie     Hybrid Journal   (Followers: 202)
Angewandte Chemie International Edition     Hybrid Journal   (Followers: 315)
Annales Universitatis Mariae Curie-Sklodowska, sectio AA – Chemia     Open Access   (Followers: 1)
Annals of Clinical Chemistry and Laboratory Medicine     Open Access   (Followers: 5)
Annual Reports in Computational Chemistry     Full-text available via subscription   (Followers: 3)
Annual Reports Section A (Inorganic Chemistry)     Full-text available via subscription   (Followers: 5)
Annual Reports Section B (Organic Chemistry)     Full-text available via subscription   (Followers: 8)
Annual Review of Chemical and Biomolecular Engineering     Full-text available via subscription   (Followers: 12)
Annual Review of Food Science and Technology     Full-text available via subscription   (Followers: 15)
Antiviral Chemistry and Chemotherapy     Open Access   (Followers: 2)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 10)
Applied Spectroscopy     Full-text available via subscription   (Followers: 26)
Applied Surface Science     Hybrid Journal   (Followers: 33)
Arabian Journal of Chemistry     Open Access   (Followers: 6)
ARKIVOC     Open Access   (Followers: 1)
Asian Journal of Applied Chemistry Research     Open Access   (Followers: 1)
Asian Journal of Biochemistry     Open Access   (Followers: 3)
Asian Journal of Chemical Sciences     Open Access   (Followers: 1)
Asian Journal of Chemistry and Pharmaceutical Sciences     Open Access   (Followers: 2)
Asian Journal of Physical and Chemical Sciences     Open Access   (Followers: 1)
Atomization and Sprays     Full-text available via subscription   (Followers: 7)
Australian Journal of Chemistry     Hybrid Journal   (Followers: 7)
Autophagy     Hybrid Journal   (Followers: 4)
Avances en Quimica     Open Access  
Biochemical Pharmacology     Hybrid Journal   (Followers: 11)
Biochemistry     Hybrid Journal   (Followers: 439)
Biochemistry Insights     Open Access   (Followers: 7)
Biochemistry Research International     Open Access   (Followers: 6)
BioChip Journal     Hybrid Journal  
Bioinorganic Chemistry and Applications     Open Access   (Followers: 10)
Bioinspired Materials     Open Access   (Followers: 5)
Biointerface Research in Applied Chemistry     Open Access   (Followers: 2)
Biointerphases     Open Access   (Followers: 1)
Biology, Medicine, & Natural Product Chemistry     Open Access   (Followers: 3)
Biomacromolecules     Hybrid Journal   (Followers: 24)
Biomass Conversion and Biorefinery     Partially Free   (Followers: 11)
Biomedical Chromatography     Hybrid Journal   (Followers: 6)
Biomolecular NMR Assignments     Hybrid Journal   (Followers: 3)
BioNanoScience     Partially Free   (Followers: 6)
Bioorganic & Medicinal Chemistry     Hybrid Journal   (Followers: 199)
Bioorganic & Medicinal Chemistry Letters     Hybrid Journal   (Followers: 88)
Bioorganic Chemistry     Hybrid Journal   (Followers: 9)
Biopolymers     Hybrid Journal   (Followers: 17)
Biosensors     Open Access   (Followers: 3)
Biotechnic and Histochemistry     Hybrid Journal   (Followers: 1)
Bitácora Digital     Open Access  
Boletin de la Sociedad Chilena de Quimica     Open Access  
Bulletin of Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences     Open Access  
Bulletin of the Chemical Society of Ethiopia     Open Access   (Followers: 1)
Bulletin of the Chemical Society of Japan     Full-text available via subscription   (Followers: 26)
Bulletin of the Korean Chemical Society     Hybrid Journal   (Followers: 1)
C - Journal of Carbon Research     Open Access   (Followers: 4)
Cakra Kimia (Indonesian E-Journal of Applied Chemistry)     Open Access  
Canadian Association of Radiologists Journal     Full-text available via subscription   (Followers: 2)
Canadian Journal of Chemistry     Hybrid Journal   (Followers: 12)
Canadian Mineralogist     Full-text available via subscription   (Followers: 7)
Carbohydrate Research     Hybrid Journal   (Followers: 23)
Carbon     Hybrid Journal   (Followers: 74)
Catalysis for Sustainable Energy     Open Access   (Followers: 10)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 9)
Catalysis Science and Technology     Hybrid Journal   (Followers: 11)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysts     Open Access   (Followers: 14)
Cellulose     Hybrid Journal   (Followers: 13)
Cereal Chemistry     Full-text available via subscription   (Followers: 5)
ChemBioEng Reviews     Full-text available via subscription   (Followers: 2)
ChemCatChem     Hybrid Journal   (Followers: 8)
Chemical and Engineering News     Free   (Followers: 23)
Chemical Bulletin of Kazakh National University     Open Access  
Chemical Communications     Full-text available via subscription   (Followers: 81)
Chemical Engineering Research and Design     Hybrid Journal   (Followers: 27)
Chemical Physics Letters : X     Open Access   (Followers: 2)
Chemical Research in Chinese Universities     Hybrid Journal   (Followers: 3)
Chemical Research in Toxicology     Hybrid Journal   (Followers: 24)
Chemical Reviews     Hybrid Journal   (Followers: 244)
Chemical Science     Open Access   (Followers: 36)
Chemical Science International Journal     Open Access   (Followers: 1)
Chemical Technology     Open Access   (Followers: 54)
Chemical Vapor Deposition     Hybrid Journal   (Followers: 5)
Chemie in Unserer Zeit     Hybrid Journal   (Followers: 56)
Chemie-Ingenieur-Technik (Cit)     Hybrid Journal   (Followers: 21)
ChemInform     Hybrid Journal   (Followers: 9)
Chemistry     Open Access  
Chemistry & Biodiversity     Hybrid Journal   (Followers: 7)
Chemistry & Biology     Full-text available via subscription   (Followers: 31)
Chemistry & Industry     Full-text available via subscription   (Followers: 8)
Chemistry - A European Journal     Hybrid Journal   (Followers: 208)
Chemistry - An Asian Journal     Hybrid Journal   (Followers: 19)
Chemistry Africa : A Journal of the Tunisian Chemical Society     Hybrid Journal  
Chemistry and Materials Research     Open Access   (Followers: 24)
Chemistry Central Journal     Open Access   (Followers: 5)
Chemistry Education Research and Practice     Free   (Followers: 5)
Chemistry Education Review     Open Access   (Followers: 2)
Chemistry in Education     Open Access   (Followers: 8)
Chemistry International     Open Access   (Followers: 3)
Chemistry Letters     Full-text available via subscription   (Followers: 47)
Chemistry of Heterocyclic Compounds     Hybrid Journal   (Followers: 4)
Chemistry of Materials     Hybrid Journal   (Followers: 308)
Chemistry of Natural Compounds     Hybrid Journal   (Followers: 10)
Chemistry World     Full-text available via subscription   (Followers: 21)
Chemistry-Didactics-Ecology-Metrology     Open Access   (Followers: 1)
ChemistryOpen     Open Access   (Followers: 1)
ChemistrySelect     Hybrid Journal  
Chemkon - Chemie Konkret, Forum Fuer Unterricht Und Didaktik     Hybrid Journal  
ChemNanoMat     Hybrid Journal   (Followers: 1)
Chemoecology     Hybrid Journal   (Followers: 3)
Chemometrics and Intelligent Laboratory Systems     Hybrid Journal   (Followers: 15)
Chemosensors     Open Access   (Followers: 1)
ChemPhotoChem     Hybrid Journal  
ChemPhysChem     Hybrid Journal   (Followers: 12)
ChemPlusChem     Hybrid Journal   (Followers: 2)
Chempublish Journal     Open Access   (Followers: 1)
ChemSystemsChem     Hybrid Journal   (Followers: 1)
ChemTexts     Hybrid Journal   (Followers: 1)
CHIMIA International Journal for Chemistry     Full-text available via subscription   (Followers: 2)
Chinese Journal of Chemistry     Hybrid Journal   (Followers: 6)
Chinese Journal of Polymer Science     Hybrid Journal   (Followers: 12)
Chromatographia     Hybrid Journal   (Followers: 22)
Chromatography     Open Access   (Followers: 3)
Chromatography Research International     Open Access   (Followers: 5)
Ciencia     Open Access   (Followers: 1)
Clay Minerals     Hybrid Journal   (Followers: 9)
Cogent Chemistry     Open Access   (Followers: 3)
Colloid and Interface Science Communications     Open Access  
Colloid and Polymer Science     Hybrid Journal   (Followers: 12)
Colloids and Interfaces     Open Access  
Colloids and Surfaces B: Biointerfaces     Hybrid Journal   (Followers: 7)
Combinatorial Chemistry & High Throughput Screening     Hybrid Journal   (Followers: 4)
Combustion Science and Technology     Hybrid Journal   (Followers: 23)
Comments on Inorganic Chemistry: A Journal of Critical Discussion of the Current Literature     Hybrid Journal   (Followers: 2)
Communications Chemistry     Open Access   (Followers: 2)
Communications Materials     Open Access   (Followers: 3)
Composite Interfaces     Hybrid Journal   (Followers: 9)
Comprehensive Chemical Kinetics     Full-text available via subscription   (Followers: 2)
Comptes Rendus Chimie     Full-text available via subscription  
Comptes Rendus Physique     Full-text available via subscription   (Followers: 2)

        1 2 3 4 | Last

Similar Journals
Journal Cover
Chromatographia
Journal Prestige (SJR): 0.514
Citation Impact (citeScore): 1
Number of Followers: 22  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1612-1112 - ISSN (Online) 0009-5893
Published by Springer-Verlag Homepage  [2626 journals]
  • Ground Organic Particles of ca. 3 μm Size as Chromatographic Separation
           Media in High Performance Liquid Chromatography
    • Abstract: Abstract A new chromatographic stationary phase was prepared by making a soft organic monolith based on thermal polymerization of methyl methacrylate and ethylene glycol di-methacrylate with an aid of gas evolution via decomposition of urea, and by crushing the monolith into particles. The original purpose of urea incorporation was formation of monolith particles with affluent mesopores, but the actual effect was reduction of the particle size to a proper range (mostly in the range of 1–5 μm with an average of ca. 3 μm), which was very crucial for improvement of separation efficiency. A series of washing processes (including common washing and reflux washing) were carried out to remove un-reacted materials and free oligomers. The columns were made by packing the organic monolith particles in glass-lined stainless-steel tubing and evaluated for their performance with the mixture of six aromatic compounds (3-phenyl-1-propanol, acetophenone, methyl benzoate, 2-nitroaniline, ethylbenzene, cumene). The overall number of theoretical plates (N) over 6 analytes based on 6 columns was 32,000 plates/column (107,000 plates/m, 9.4 µm plate height).
      PubDate: 2020-06-01
       
  • Quantification and Analysis of Trace Levels of Phenicols in Feed by Liquid
           Chromatography–Mass Spectrometry
    • Abstract: Abstract A sensitive and reliable method using liquid chromatography–negative electrospray ionization mass spectrometry was developed for the simultaneous determination of chloramphenicol, florfenicol, and thiamphenicol at trace levels in animal feed. The analytes were extracted from grinded feed with ethyl acetate. Further the ethyl acetate was evaporated, residue resuspended in Milli-Q water, defatted with n-hexane, and solid phase extracted using BondELUT C18 cartridges. Separation was carried out on a C6 phenyl column with a mobile phase consisting of 0.1% formic acid in Milli-Q water and acetonitrile. The detector response was linear over the tested concentration range from 100 to 1000 µg kg−1. The recovery values for all analytes in feed were higher than 79% with RSD for repeatability and reproducibility in the ranges of 4.5–10.9% and 8.4–13.5%, respectively. CCα and CCβ varied between 76.8 and 86.1 µg kg−1, and between 111.3 and 159.9 µg kg−1, respectively. The results showed that this method is effective for the quantification of phenicols in non-target feed.
      PubDate: 2020-06-01
       
  • Statistically Designed, Targeted Profile UPLC Method Development for Assay
           and Purity of Haloperidol in Haloperidol Drug Substance and Haloperidol
           1 mg Tablets
    • Abstract: Abstract In view of the US pharmacopeia (USP)-proposed general chapter \(\left\langle {1220} \right\rangle\) “The Analytical Procedure Lifecycle” and ICH-proposed ICHQ14 guideline “Analytical Procedure Development”, application of quality by design approach during analytical method development gains a significant importance. Methods developed by QbD approach will be more robust and thereby decrease efforts for method performance verification and post approval changes. Additionally, these methods will be more QC friendly as out of trend or out of specification results due to incompetent methods will be reduced and it will support the approach of life cycle management for analytical procedures. The present study deals with the development of an analytical targeted profile (ATP)-based, rapid, specific, precise, and mass-compatible RP-UPLC method with proven design space (DS) for the quantitative determination of Haloperidol and its degradation products in Haloperidol drug substance and Haloperidol 1 mg tablets. Using 5 different column chemistries, 4 different pH ranges, oven temperatures, and flow rates as variables experiments were carried out and statistically evaluated to finalize the chromatographic conditions. The significance and interaction effects of variables on the critical attributes (tailing factor and resolution) were evaluated through statistical analysis like analysis of variance (ANOVA). DOE study was also applied for the sample preparation to prove robustness of the sample preparation procedure. Forced degradation study was carried to demonstrate the stability-indicating nature of the method. Validation for active and available impurities was performed as per ICH and ANVISA guidelines and the method was found to be linear, accurate, specific, precise, and robust. Specificity of the method was confirmed orthogonally using QDa (mass detector) along with PDA detector. The method can be employed for release and stability testing of Haloperidol drug substance as well as Haloperidol 1 mg tablets.
      PubDate: 2020-06-01
       
  • An Efficient Method for Endotoxin Removal from Snake Antivenoms
    • Abstract: Abstract Parenterally administered snake antivenom immunoglobulins are the only specific treatment for envenoming by snakebites. Endotoxin removal is a necessary part of good manufacturing practice for antivenom products to avoid life-threatening consequences associated with injecting endotoxin-contaminated product. Optimization of pH is an essential factor in endotoxin purification. This study aimed to compare ultrafiltration, ion-exchange chromatography and affinity resin-based chromatography techniques at different pH values to select the depyrogenation method with the highest endotoxin removal efficiency and optimum protein/product recovery. Affinity resin-based chromatography achieved 91.2% protein recovery at acidic pH without detectable endotoxins, while ion-exchange chromatography achieved 74.42% protein recovery at pH 7.5. In contrast, ultrafiltration achieved the lowest protein recovery compared to other chromatography techniques. In addition, ultrafiltration was ineffective in removing serum albumin (~ 42–57 kDa) and low molecular weight (MW) Fc fragments (~ 24–31 kDa). In conclusion, affinity resin-based chromatography has proven to be the most effective endotoxin removal method, while ultrafiltration may not be appropriate for the removal of bacterial LPS from antivenom sera. Moreover, this study demonstrated the existence of an optimum pH for each chromatographic method for the purpose of producing sterile and endotoxin-free snake antivenoms.
      PubDate: 2020-06-01
       
  • Triazine-Based Polymeric Network-Modified Magnetic Nanoparticles (NPs) as
           an Efficient Sorbent to Extract 1-Naphthylacetic Acid in Fruit and
           Vegetable Samples
    • Abstract: Abstract In this study, a triazine-based polymeric network-modified magnetic nanoparticles (TPN/MNPs) was synthesized and applied as adsorbent for extraction of 1-naphthylacetic acid (NAA) from the fruit and vegetable samples followed by HPLC determination. The synthesized TPN/MNPs were characterized by the vibrating sample magnetometry (VSM), Fourier-transform infrared spectroscopy (FT-IR), field emission-scanning electron microscopy (FE-SEM) and thermogravimetric analysis (TGA). The factors influencing the extraction efficiency including pH, sorbent amount, salt concentration, extraction time, sample volume and desorption conditions were studied and optimized. Under the optimal conditions, good linearity was obtained in the range of 1.0–500 µg L−1. The limit of detection (LOD) and limit of quantification (LOQ) were 0.3 µg L−1 and 1.0 µg L−1, respectively. The relative standard deviations (RSDs) of intra-day and inter-day were less than 9.5% at 10 and 100 µg L−1 of NAA. The method was successfully applied for extraction and determination of NAA in the fruit and vegetable samples including cucumber, tomato and apple and good recoveries were obtained (94.5–96.5%).
      PubDate: 2020-05-20
       
  • Metabolic Phenotyping Using UPLC–MS and Rapid Microbore UPLC–IM–MS:
           Determination of the Effect of Different Dietary Regimes on the Urinary
           Metabolome of the Rat
    • Abstract: Abstract A rapid reversed-phase gradient method employing a 50 mm × 1 mm i.d., C18 microbore column, combined with ion mobility and high-resolution mass spectrometry, was applied to the metabolic phenotyping of urine samples obtained from rats receiving different diets. This method was directly compared to a “conventional” method employing a 150 × 2.1 mm i.d. column packed with the same C18 bonded phase using the same samples. Multivariate statistical analysis of the resulting data showed similar class discrimination for both microbore and conventional methods, despite the detection of fewer mass/retention time features by the former. Multivariate statistical analysis highlighted a number of ions that represented diet-specific markers in the samples. Several of these were then identified using the combination of mass, ion-mobility-derived collision cross section and retention time including N-acetylglutamate, urocanic acid, and xanthurenic acid. Kynurenic acid was tentatively identified based on mass and ion mobility data.
      PubDate: 2020-05-15
       
  • Determination of 13 Vitamin B and the Related Compounds Using HPLC with UV
           Detection and Application to Food Supplements
    • Abstract: Abstract A high-performance liquid chromatographic method was developed for the separation and determination of 13 vitamin B compounds, including thiamin, riboflavin, riboflavin 5′-monophosphate, pyridoxine, hydroxocobalamin, cyanocobalamin, adenosylcobalamin, methylcobalamin, niacin, niacinamide, pantothenic acid, folic acid, and biotin. The method consisted of an ODS column, a gradient elution using pH 3.0 phosphate buffer–acetonitrile, ion-pairing reagent as mobile phase at 1.0 mL min−1, and UV detection at 210 nm. As a result, the 13 vitamin B compounds were separated in 60 min, and the specificity, linearity, range, limit of detection, limit of quantitation, intra- and inter-day precision, and recovery were satisfactory. The limit of detections ranged from 0.03 to 0.41 µg mL−1. Intra- and inter-day precision of peak area, expressed as RSD, were 0.542–5.144% and 0.216–6.367%, respectively. The method was used to evaluate vitamin B compounds in energy drinks and multivitamin pills. In case of energy drink analysis, the method identified and evaluated not only vitamin B compounds but also major ingredients, such as caffeine, vanillin, and benzoic acid. The vitamin B compounds in energy drinks and multivitamin pills were also quantitated and compared with values listed on each product label. Each quantitative value was close to the label values, suggesting high quantitative ability of the developed method.
      PubDate: 2020-05-14
       
  • Determination of Moniliformin in Vegetable Oil by Solid-Phase
           Extraction–Hydrophilic Interaction Chromatography–Tandem Mass
           Spectrometry
    • Abstract: Abstract An analytical method based on solid-phase extraction–hydrophilic interaction chromatography–tandem mass spectrometry (SPE–HILIC–MS/MS) has been developed to quantify moniliformin in vegetable oil. The sample was extracted by methanol and purified by an Oasis MAX solid-phase extraction column. Following purification, it was separated by a Waters HILIC hydrophilic interaction column. Acetonitrile and 0.5 mM ammonium acetate solution were used as a mobile phase for gradient elution. An electrospray-negative ion multiple-reaction monitoring mode was used to quantify moniliformin by external standard method. In the mass concentration range of 0.1–10 μg/L, the correlation coefficient of moniliformin was 0.9997. The detection limit of this method was 0.03 μg/L, and the limit of quantification was 0.1 μg/L. When the three levels of 1.0, 2.0 and 5.0 μg/kg moniliformin were added, the recovery was 84.6%–98.2% with a relative standard deviation of 1.3%–5.1%. The results indicated that this method is simple, fast, sensitive, reproducible, and can be used to determine moniliformin in vegetable oil.
      PubDate: 2020-05-13
       
  • Amino Acid Profiles and Compositions of Different Cultivars of Panicum
           miliaceum L.
    • Abstract: Amino acids are valuable nutrients, responsible for a variety of tasks in the human body. A favourable amino acid profile in gluten-free crops, such as millet, can thus be beneficial for human health, which is why 35 proso millet (Panicum miliaceum L.) samples, comprising 23 whole and 12 dehulled, were investigated regarding their amino acid profiles and compositions using acidic hydrolysis and ion-exchange chromatography with ninhydrin derivatization and subsequent detection with photometry. Results for amino acid compositions were compared with gluten-containing wheat and other gluten-free cereals. Furthermore, gained values were put in contrast to estimated essential amino acid requirements for adult humans. The study was able to show that cultivars of proso millet differ and that dehulling does not significantly influence the amino acid compositions. Furthermore, the results display that Panicum miliaceum L. holds more essential amino acids than other gluten-free grains and exhibits high amounts of leucine and alanine. The methionine content differs greatly between samples, which means that choosing certain cultivars is important to ensure a high content. The most abundant amino acids in proso millet grains are glutamic acid/glutamine (2.13 ± 0.34 g per 100 g), alanine (1.06 ± 0.18 g per 100 g) and leucine (1.36 ± 0.24 g per 100 g). Graphic abstract
      PubDate: 2020-05-13
       
  • Detection of Two Genotoxic Impurities in Drug Substance and Preparation of
           Imatinib Mesylate by LC–MS/MS
    • Abstract: As a potential DNA damaging substance, genotoxic impurities have been concerned by regulatory authorities in various countries. Two genotoxic impurities were found in imatinib mesylate which was a classical small molecule inhibitor of tyrosine kinase, and the analysis method has never been reported. A LC–MS/MS method was developed for the analysis of two genotoxic impurity materials: N-(5-amino-2-methylphenyl)-4-(3-pyridyl)-2-aminopyrimidine (IMA) and N-(2-methyl-5-nitrophenyl)-4-(pyridin-3-yl) pyrimidin-2-amine (IMN). The HPLC method utilized an ACQUITY UPLC HSS T3 C18 (150 × 2.1 mm, 1.7 μm) maintained at 40 °C. The mobile phase consisted of 0.02 M ammonium formate buffer (pH 3.4) and acetonitrile (containing 0.05% formic acid) in gradient elution mode. Detection was performed by triple quadrupole mass spectrometry fitted with ESI probe functioning in the positive ion mode and the following m/z 278/106 and 308/262 were used as qualifier and quantifier transitions. Flow rate was 0.4 mL min−1. The validation data demonstrated that the method had high sensitivity and selectivity. A linear calibration curve (correlation coefficient, r > 0.998) was obtained at the concentration range of 0.02–35.27 and 0.02–28.86 ng mL−1, respectively. The LOD of IMA in drug substances, tablets, and capsules were 0.0039, 0.0043, and 0.0044 ng mL−1, and LOD of IMN were 0.0034, 0.0035, and 0.0036 ng mL−1, respectively. Precision and accuracy were within the acceptable limit. The drug substances, tablets, and capsules from three manufacturers were used for inspection and all samples met the requirements. The developed LC–MS/MS method is robust and can be applied to detect the genotoxic impurities in imatinib mesylate. Graphic Mixed solution of Imatinib, IMA and IMN. A new LC-MS/MS method was developed for the analysis of two genotoxic impurities materials: N-(5-amino-2-methylphenyl)-4-(3-pyridyl)-2-aminopyrimidine and N-(2-methyl-5-nitrophenyl)-4-(pyridin-3-yl) pyrimidin-2-amine (IMN)
      PubDate: 2020-05-12
       
  • Congress, Conferences, and Workshops
    • PubDate: 2020-05-08
       
  • Effects of the Sorbent Backbone and Side Chain on Retention Mechanisms
           Using Immobilized Polysaccharide-Based Stationary Phases in Normal Phase
           Mode
    • Abstract: Abstract The effects of the side chain and polymer backbone on the retention mechanisms of four polysaccharide-based sorbents, namely amylose 3,5-dimethylphenylcarbamate (Chiralpak IA), cellulose 3,5-dimethylphenylcarbamate (Chiralpak IB), amylose 3,5-dichlorophenylcarbamate (Chiralpak IE), and cellulose 3,5-dichlorophenylcarbamate (Chiralpak IC), were investigated using simple achiral molecules with distinct functional groups as probes. The thermodynamic properties of solute retention behaviors were investigated using retention factor data, van’t Hoff plots, adsorption isotherms, and retention models. Frontal analysis was used to obtain the adsorption isotherms of acetone (AC) and isopropanol (IPA). The results revealed that the adsorptions of AC on the four sorbents followed Langmuir isotherms, whereas heterogeneous adsorption mechanisms more accurately fit the adsorptions of IPA. For solutes associated with hydrogen-bonding groups, the retention factors and enthalpy changes suggest that cellulose sorbents may have more binding sites available than the amylose sorbents. The van’t Hoff analysis indicated that sorbents with Cl-substituted phenyl groups enhanced the binding strength of sorbent NH groups with the solutes. For aromatic solutes, larger retention factors and stronger adsorption energies were found for the cellulose sorbents. The results suggested that side chains with Cl-substituted phenyl groups weakened the π interactions. The inferences obtained from these sorbents were used for the interpretation of the chiral recognition mechanisms of pantolactone enantiomers.
      PubDate: 2020-05-05
       
  • Simultaneous Determination of Active Ingredients in Multicomponent Common
           Over the Counter Tablets in the Present of Parabens and 4-Aminophenol by
           HPLC
    • Abstract: Abstract A new selective reverse-phase high-performance liquid chromatography method with an attitude of practical use in pharmaceutical laboratories for simultaneous determination of Ascorbic acid, Acetaminophen, phenylephrine, Caffeine, Pamabrom, Guaifenesin, Dextromethorphan, Pyrilamine, Chlorpheniramine maleate, Ibuprofen in the presence of Methyl, Ethyl, Butyl Parabens as preservatives has been developed and validated. These active pharmaceutical ingredients widely used in a variety of cough and cold medicines. The separation was carried out on an Atlantis dC18 column including 4.6 mm inner diameter, 150 mm length and particle size of 3 μm, using a mobile phase which consisted of an ion-pairing agent (sodium salt of heptane sulphonic acid) as a buffer solution mixed with acetonitrile as an organic modifier at a flow rate of 1 mL min−1 on a gradient system. The investigation was carried out on wavelength program detection to quantify the very low concentration of Dextromethorphan and Chlorpheniramine and high concentration of Acetaminophen, Guaifenesin, Ibuprofen, Ascorbic Acid at the wavelengths of 290 and 215 nm. The temperature was maintained at 40 °C. The method was shown to be linear (R2 > 0.996), accurate (recoveries 97.77–103.94%), precise (RSD ≤ 1.0%), sensitive, specific, simple, fast and robust. The proposed reverse phase-liquid chromatography method was successfully applied to the routine analysis of the Over-The-Counter tablets containing these active pharmaceutical ingredients without any interference with excipients and parabens and 4-aminophenol.
      PubDate: 2020-05-04
       
  • Reverse Micelle Hollow Fiber Liquid-Phase Microextraction Coupled with
           HPLC for the Determination of Q-Markers of Anthraquinones in Rhubarb and
           Their Plasma Protein Binding Rates
    • Abstract: A three-phase hollow fiber liquid-phase microextraction based on reversed micellar supramolecule was developed and employed for the determination of quality markers of three anthraquinones in Rhubarb and their plasma protein binding rates. Moreover, the extraction mechanism of reversed micellar supramolecule and determination mechanism of plasma protein binding rate by the proposed method are both explored. In this procedure, n-nonanol was impregnated in the wall pores and reverse micelle of tetrabutylammonium chloride/n-nonanol filled in lumen of hollow fibers, which were covered with a thin salt film and used for the microextraction of target compounds prior to HPLC analysis. Important extraction parameters including extraction solvent type, reversed micellar supramolecule type and concentration, sample phase pH, salt concentration, stirring rate, extraction time, and binding time between active compound and plasma protein were investigated. Under the optimized conditions, limits of detection were 0.1–0.4 ng/mL with enrichment factors in the range of 54.2–100.7. The linearities were 0.5–500 ng/mL with r2 ≥ 0.9838. Satisfactory accuracies (relative recoveries 95.7–98.3%) were also obtained. The average plasma protein binding rates of rhein, chrysophenol, and physcion were 96.7%, 41.8%, and 46.7%, respectively. The results showed that the proposed procedure can not only extract and concentrate anthraquinones in Rhubarb, but also determine their plasma protein binding rates. Graphic
      PubDate: 2020-04-30
       
  • Rapid Separation and Screening of Mycophenolate Mofetil and Mycophenolic
           Acid with a Novel (Vinyl Ester) Resin Molecular Imprinted Monolithic
           Column
    • Abstract: Abstract We introduced a new molecular imprinted polymers (MIPs) monolithic column of Mycophenolate mofetil (MMF) for HPLC. The monolithic column was prepared using MMF as the template molecule, methcrylic acid (MAA) as the functional monomer, vinyl ester resin as the crosslinking agent and AIBN as the initiator. HPLC was used to study the binding and separation performance of MIPs for template MMF and its cleavage product Mycophenolic acid (MPA). For chromatographic analysis the effects on the separation, mobile phase composition, flowrate and pH value were discussed respectively. Under the selected chromatographic conditions, MMF and MPA could achieve base line separation within 4 min with a separation degree of 2.68. Moreover, the linearity of the calibration plot was evaluated of seven spiked samples (2.0–100.0 µg·mL−1) in plasma, and the limit of detection (LOD) for MMF in plasma and the stability of the monolithic column were also studied. Twelve-hour pharmacokinetic profile of both MMF and MPA for a renal transplant recipient receiving oral dosing of 1000 mg MMF was investigated. Results indicated that this method could be applied for separation and screening of MMF and MPA, It provided a simple and fast method for assaying this drug in plasma sample.
      PubDate: 2020-04-28
       
  • Microfluidic Paper-based Analytical Devices in Clinical Applications
    • Abstract: Abstract Microfluidic paper-based analytical devices (µPADs) take the paper as a base material and integrate nanoscale microchannel on it for multiple detections. Its unique properties like low cost, portability, simple operation, and easy to save make it better than the traditional microfluidic chips. While designed originally for point-of-care medical diagnostics, µPADs have attracted the attention of many researchers in the fields of environmental monitoring, water quality, and food safety. The novelty of this paper is to present a detailed overview of µPADs for clinical applications. Firstly, a brief introduction to production methods, characteristics, and applications of these methods have been given. Secondly, the basic implementation, working principles, and corresponding performance of detection methods of clinical devices have been discussed, which enable the µPADs to detect biomarkers, human cells, bacteria, and viruses in a short time. Lastly, the factors that limit µPADs commercial applications, and their future research directions have also been briefly summarized.
      PubDate: 2020-04-24
       
  • Enantiomeric Separation on a Homochiral Porous Organic Cage-Based Chiral
           Stationary Phase by Gas Chromatography
    • Abstract: Abstract Porous organic cages (POCs) are an emerging class of porous molecular materials which self-assembled by discrete, shape-persistent, cage-like molecules and have recently received intensive interest in diverse fields. In this work, a hydroxyl-functionalized homochiral POC was synthesized by [4 + 6] condensation of 2-hydroxy-1,3,5-triformylbenzene with (1R, 2R)-diaminocyclohexane and coated on a capillary column for gas chromatography (GC) separations. Forty-one pairs of enantiomers belonging to various classes have been resolved on the column, including alcohols, diols, esters, lactones, halohydrocarbons, ethers, epoxides, ketones and sulfoxides. Compared with β-cyclodextrin derivative-based commercial β-DEX 120 column, previously reported chiral POCs- (CC9 and CC10) based columns, there are 12, 27 and 19 pairs of studied enantiomers cannot be resolved on β-DEX 120 column, CC9 column and CC10 column, respectively. Besides, both separation factors and resolution values of some racemates are higher on this column than those on β-DEX 120 column, CC9 column and CC10 column. The results demonstrate that the column exhibits good chiral recognition complementarity or superior chiral resolution capability to those columns which used for comparison, and the introduction of hydroxyl group enhances hydrogen-bonding interaction to some racemates, leading to better enantioselectivity. The column also shows excellent separation performance toward positional isomers of dichlorobenzene, dibromobenzene, nitrotoluene, chlorotoluene, nitrobromobenzene and nitrochlorobenzene. The retention time and selectivity of analytes have no significant changes after more than 500 injections and 260 °C conditioned for 6 h, showing the good repeatability and thermal stability of the column. This work indicates the promising prospect of POCs for GC separation, especially for the separation of enantiomers and also demonstrates the significance of design and synthesis of more functionalized chiral POCs for GC enantioseparation that broaden the enantiomer separation scope and applicability of POCs-based columns through their chiral recognition complementarities.
      PubDate: 2020-04-23
       
  • Dansyl Chloride as a Derivatizing Agent for the Analysis of Biogenic
           Amines by CZE-UV
    • Abstract: Biogenic amines (BAs) are important compounds that can be used in the quality control of food and beverages. BA analysis is a challenging task that can be made easier by applying a derivatizing agent like dansyl chloride (DNS). The optimized capillary zone electrophoresis (CZE) separation of the DNS-BA derivates (derivates of cadaverine, histamine, putrescine, tryptamine, and tyramine) was performed using benzylamine as an internal standard, a potential of 18 kV, a temperature of 23 °C, a running buffer consisting of phosphoric acid, 120 mmol L−1, pH 2.5, and an hydrodynamic injection at 25 mBar for 6 s. All calibration curves had r2 higher than 0.99, and limits of detection (LODs) ranged from 7 to 50 µg L−1. The developed methodology was tested in cheese and yogurt samples. DNS showed to be an alternative derivatization reagent not only because it produced UV-detectable derivates (214 nm), but also because of its stability, aqueous solubility, high selectivity and sensitivity, reduced impurities, and simple preparation steps. Graphic abstract
      PubDate: 2020-04-22
       
  • Correction to: Bioanalytical Applications of Microextraction Techniques: A
           Review of Reviews
    • Abstract: In the original publication, the phrase “Liquid phase” in Table 1 column 1 was included in the wrong line. The phrase needs to be included in row 13 in front of LPME.
      PubDate: 2020-04-13
       
  • Congress, Conferences, and Workshops
    • PubDate: 2020-04-04
       
 
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