Publisher: Elsevier   (Total: 3161 journals)

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Showing 1 - 200 of 3161 Journals sorted alphabetically
Academic Pediatrics     Hybrid Journal   (Followers: 39, SJR: 1.655, CiteScore: 2)
Academic Radiology     Hybrid Journal   (Followers: 26, SJR: 1.015, CiteScore: 2)
Accident Analysis & Prevention     Partially Free   (Followers: 106, SJR: 1.462, CiteScore: 3)
Accounting Forum     Hybrid Journal   (Followers: 28, SJR: 0.932, CiteScore: 2)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 44, SJR: 1.771, CiteScore: 3)
Achievements in the Life Sciences     Open Access   (Followers: 7)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 6)
Acta Astronautica     Hybrid Journal   (Followers: 446, SJR: 0.758, CiteScore: 2)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 2)
Acta Biomaterialia     Hybrid Journal   (Followers: 30, SJR: 1.967, CiteScore: 7)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription   (Followers: 3)
Acta de Investigación Psicológica     Open Access   (Followers: 2)
Acta Ecologica Sinica     Open Access   (Followers: 11, SJR: 0.18, CiteScore: 1)
Acta Histochemica     Hybrid Journal   (Followers: 5, SJR: 0.661, CiteScore: 2)
Acta Materialia     Hybrid Journal   (Followers: 324, SJR: 3.263, CiteScore: 6)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.504, CiteScore: 1)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.542, CiteScore: 1)
Acta Oecologica     Hybrid Journal   (Followers: 12, SJR: 0.834, CiteScore: 2)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription  
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 2, SJR: 0.307, CiteScore: 0)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 2, SJR: 1.793, CiteScore: 6)
Acta Psychologica     Hybrid Journal   (Followers: 26, SJR: 1.331, CiteScore: 2)
Acta Sociológica     Open Access   (Followers: 1)
Acta Tropica     Hybrid Journal   (Followers: 6, SJR: 1.052, CiteScore: 2)
Acta Urológica Portuguesa     Open Access   (Followers: 1)
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 3, SJR: 0.374, CiteScore: 1)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 2)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 3, SJR: 0.344, CiteScore: 1)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 1)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 7, SJR: 0.19, CiteScore: 0)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 3)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 8)
Acute Pain     Full-text available via subscription   (Followers: 15, SJR: 2.671, CiteScore: 5)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.53, CiteScore: 4)
Addictive Behaviors     Hybrid Journal   (Followers: 18, SJR: 1.29, CiteScore: 3)
Addictive Behaviors Reports     Open Access   (Followers: 9, SJR: 0.755, CiteScore: 2)
Additive Manufacturing     Hybrid Journal   (Followers: 13, SJR: 2.611, CiteScore: 8)
Additives for Polymers     Full-text available via subscription   (Followers: 22)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 188, SJR: 4.09, CiteScore: 13)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 13, SJR: 1.167, CiteScore: 4)
Advanced Powder Technology     Hybrid Journal   (Followers: 17, SJR: 0.694, CiteScore: 3)
Advances in Accounting     Hybrid Journal   (Followers: 9, SJR: 0.277, CiteScore: 1)
Advances in Agronomy     Full-text available via subscription   (Followers: 17, SJR: 2.384, CiteScore: 5)
Advances in Anesthesia     Full-text available via subscription   (Followers: 30, SJR: 0.126, CiteScore: 0)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 2)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 12, SJR: 0.992, CiteScore: 1)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 12, SJR: 1.551, CiteScore: 4)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 24, SJR: 2.089, CiteScore: 5)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 15, SJR: 0.572, CiteScore: 2)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.61, CiteScore: 7)
Advances in Botanical Research     Full-text available via subscription   (Followers: 1, SJR: 0.686, CiteScore: 2)
Advances in Cancer Research     Full-text available via subscription   (Followers: 35, SJR: 3.043, CiteScore: 6)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 1.453, CiteScore: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 1.992, CiteScore: 5)
Advances in Cell Aging and Gerontology     Full-text available via subscription   (Followers: 5)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 14)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 29, SJR: 0.156, CiteScore: 1)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 11, SJR: 0.713, CiteScore: 1)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 11, SJR: 1.316, CiteScore: 2)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 26, SJR: 1.562, CiteScore: 3)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 21, SJR: 1.977, CiteScore: 8)
Advances in Computers     Full-text available via subscription   (Followers: 14, SJR: 0.205, CiteScore: 1)
Advances in Dermatology     Full-text available via subscription   (Followers: 16)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 14)
Advances in Digestive Medicine     Open Access   (Followers: 13)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 7)
Advances in Drug Research     Full-text available via subscription   (Followers: 26)
Advances in Ecological Research     Full-text available via subscription   (Followers: 45, SJR: 2.524, CiteScore: 4)
Advances in Engineering Software     Hybrid Journal   (Followers: 30, SJR: 1.159, CiteScore: 4)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 9)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 52, SJR: 5.39, CiteScore: 8)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 2)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 9)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 68, SJR: 0.591, CiteScore: 2)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 17)
Advances in Genetics     Full-text available via subscription   (Followers: 21, SJR: 1.354, CiteScore: 4)
Advances in Genome Biology     Full-text available via subscription   (Followers: 12, SJR: 12.74, CiteScore: 13)
Advances in Geophysics     Full-text available via subscription   (Followers: 8, SJR: 1.193, CiteScore: 3)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 26, SJR: 0.368, CiteScore: 1)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 11, SJR: 0.749, CiteScore: 3)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 26)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 3, SJR: 0.193, CiteScore: 0)
Advances in Immunology     Full-text available via subscription   (Followers: 37, SJR: 4.433, CiteScore: 6)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 10, SJR: 1.163, CiteScore: 2)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 2, SJR: 1.938, CiteScore: 3)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 6, SJR: 0.176, CiteScore: 0)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 3)
Advances in Life Course Research     Hybrid Journal   (Followers: 9, SJR: 0.682, CiteScore: 2)
Advances in Lipobiology     Full-text available via subscription   (Followers: 1)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 8)
Advances in Marine Biology     Full-text available via subscription   (Followers: 21, SJR: 0.88, CiteScore: 2)
Advances in Mathematics     Full-text available via subscription   (Followers: 17, SJR: 3.027, CiteScore: 2)
Advances in Medical Sciences     Hybrid Journal   (Followers: 9, SJR: 0.694, CiteScore: 2)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 6)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 5, SJR: 1.158, CiteScore: 3)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 26)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 8)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 7, SJR: 0.182, CiteScore: 0)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 5)
Advances in Oncobiology     Full-text available via subscription   (Followers: 2)
Advances in Organ Biology     Full-text available via subscription   (Followers: 2)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 18, SJR: 1.875, CiteScore: 4)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.174, CiteScore: 0)
Advances in Parasitology     Full-text available via subscription   (Followers: 6, SJR: 1.579, CiteScore: 4)
Advances in Pediatrics     Full-text available via subscription   (Followers: 27, SJR: 0.461, CiteScore: 1)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 19)
Advances in Pharmacology     Full-text available via subscription   (Followers: 17, SJR: 1.536, CiteScore: 3)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 10, SJR: 0.574, CiteScore: 1)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.109, CiteScore: 1)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 11)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 6)
Advances in Porous Media     Full-text available via subscription   (Followers: 5)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 19)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 20, SJR: 0.791, CiteScore: 2)
Advances in Psychology     Full-text available via subscription   (Followers: 69)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 7, SJR: 0.371, CiteScore: 1)
Advances in Radiation Oncology     Open Access   (Followers: 3, SJR: 0.263, CiteScore: 1)
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 3, SJR: 0.101, CiteScore: 0)
Advances in Space Biology and Medicine     Full-text available via subscription   (Followers: 7)
Advances in Space Research     Full-text available via subscription   (Followers: 431, SJR: 0.569, CiteScore: 2)
Advances in Structural Biology     Full-text available via subscription   (Followers: 6)
Advances in Surgery     Full-text available via subscription   (Followers: 13, SJR: 0.555, CiteScore: 2)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 37, SJR: 2.208, CiteScore: 4)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 20)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 15)
Advances in Virus Research     Full-text available via subscription   (Followers: 6, SJR: 2.262, CiteScore: 5)
Advances in Water Resources     Hybrid Journal   (Followers: 56, SJR: 1.551, CiteScore: 3)
Aeolian Research     Hybrid Journal   (Followers: 6, SJR: 1.117, CiteScore: 3)
Aerospace Science and Technology     Hybrid Journal   (Followers: 395, SJR: 0.796, CiteScore: 3)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.42, CiteScore: 2)
African J. of Emergency Medicine     Open Access   (Followers: 6, SJR: 0.296, CiteScore: 0)
Ageing Research Reviews     Hybrid Journal   (Followers: 12, SJR: 3.671, CiteScore: 9)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 488, SJR: 1.238, CiteScore: 3)
Agri Gene     Hybrid Journal   (Followers: 1, SJR: 0.13, CiteScore: 0)
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 18, SJR: 1.818, CiteScore: 5)
Agricultural Systems     Hybrid Journal   (Followers: 32, SJR: 1.156, CiteScore: 4)
Agricultural Water Management     Hybrid Journal   (Followers: 46, SJR: 1.272, CiteScore: 3)
Agriculture and Agricultural Science Procedia     Open Access   (Followers: 4)
Agriculture and Natural Resources     Open Access   (Followers: 3)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 58, SJR: 1.747, CiteScore: 4)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.589, CiteScore: 3)
Air Medical J.     Hybrid Journal   (Followers: 8, SJR: 0.26, CiteScore: 0)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.19, CiteScore: 0)
Alcohol     Hybrid Journal   (Followers: 12, SJR: 1.153, CiteScore: 3)
Alcoholism and Drug Addiction     Open Access   (Followers: 12)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 2, SJR: 0.604, CiteScore: 3)
Alexandria J. of Medicine     Open Access   (Followers: 1, SJR: 0.191, CiteScore: 1)
Algal Research     Partially Free   (Followers: 11, SJR: 1.142, CiteScore: 4)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 2)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.504, CiteScore: 1)
Allergology Intl.     Open Access   (Followers: 5, SJR: 1.148, CiteScore: 2)
Alpha Omegan     Full-text available via subscription   (SJR: 3.521, CiteScore: 6)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 11, SJR: 0.201, CiteScore: 1)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 55, SJR: 4.66, CiteScore: 10)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 6, SJR: 1.796, CiteScore: 4)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 6, SJR: 1.108, CiteScore: 3)
Ambulatory Pediatrics     Hybrid Journal   (Followers: 5)
American Heart J.     Hybrid Journal   (Followers: 58, SJR: 3.267, CiteScore: 4)
American J. of Cardiology     Hybrid Journal   (Followers: 67, SJR: 1.93, CiteScore: 3)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 48, SJR: 0.604, CiteScore: 1)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 13)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 15, SJR: 1.524, CiteScore: 3)
American J. of Human Genetics     Hybrid Journal   (Followers: 39, SJR: 7.45, CiteScore: 8)
American J. of Infection Control     Hybrid Journal   (Followers: 29, SJR: 1.062, CiteScore: 2)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 37, SJR: 2.973, CiteScore: 4)
American J. of Medicine     Hybrid Journal   (Followers: 50)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3, SJR: 1.967, CiteScore: 2)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 264, SJR: 2.7, CiteScore: 4)
American J. of Ophthalmology     Hybrid Journal   (Followers: 67, SJR: 3.184, CiteScore: 4)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 5, SJR: 0.265, CiteScore: 0)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.289, CiteScore: 1)
American J. of Otolaryngology     Hybrid Journal   (Followers: 25, SJR: 0.59, CiteScore: 1)
American J. of Pathology     Hybrid Journal   (Followers: 32, SJR: 2.139, CiteScore: 4)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 30, SJR: 2.164, CiteScore: 4)
American J. of Surgery     Hybrid Journal   (Followers: 39, SJR: 1.141, CiteScore: 2)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 12, SJR: 0.767, CiteScore: 1)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 7)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.144, CiteScore: 3)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 67, SJR: 0.138, CiteScore: 0)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 25, SJR: 0.411, CiteScore: 1)
Anales de Cirugia Vascular     Full-text available via subscription   (Followers: 1)
Anales de Pediatría     Full-text available via subscription   (Followers: 3, SJR: 0.277, CiteScore: 0)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription  
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 6, SJR: 4.849, CiteScore: 10)
Analytica Chimica Acta     Hybrid Journal   (Followers: 44, SJR: 1.512, CiteScore: 5)
Analytica Chimica Acta : X     Open Access  
Analytical Biochemistry     Hybrid Journal   (Followers: 215, SJR: 0.633, CiteScore: 2)
Analytical Chemistry Research     Open Access   (Followers: 13, SJR: 0.411, CiteScore: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 14)
Anesthésie & Réanimation     Full-text available via subscription   (Followers: 2)
Anesthesiology Clinics     Full-text available via subscription   (Followers: 25, SJR: 0.683, CiteScore: 2)
Angiología     Full-text available via subscription   (SJR: 0.121, CiteScore: 0)
Angiologia e Cirurgia Vascular     Open Access   (Followers: 1, SJR: 0.111, CiteScore: 0)
Animal Behaviour     Hybrid Journal   (Followers: 237, SJR: 1.58, CiteScore: 3)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 7, SJR: 0.937, CiteScore: 2)
Animal Reproduction Science     Hybrid Journal   (Followers: 7, SJR: 0.704, CiteScore: 2)
Annales d'Endocrinologie     Full-text available via subscription   (Followers: 3, SJR: 0.451, CiteScore: 1)

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Similar Journals
Journal Cover
Analytical Chemistry Research
Journal Prestige (SJR): 0.411
Citation Impact (citeScore): 2
Number of Followers: 13  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2214-1812
Published by Elsevier Homepage  [3161 journals]
  • Cloud point extraction for analysis of antiretrovirals in human plasma by
           uflc-esi-ms/ms

    • Authors: Gabriel A. Hunzicker; Gustavo J. Hein; Silvia R. Hernández; Jorgelina C. Altamirano
      Pages: 1 - 8
      Abstract: Publication date: Available online 21 August 2015
      Source:Analytical Chemistry Research
      Author(s): Gabriel A. Hunzicker, Gustavo J. Hein, Silvia R. Hernández, Jorgelina C. Altamirano
      An analytical methodology based on cloud point extraction (CPE) coupled to Ultra-Fast Liquid Chromatography and electrospray tandem mass spectrometry (UFLC-MS/MS) was developed for analysis of Abacavir (ABC), Efavirenz (EFV), Lamivudine (3TC) and Nelfinavir (NFV) in human plasma. It is the first time that CPE was used for extraction of antiretrovirals (ARV) from plasma. The effects of relevant physic-chemical variables on analytical response of each ARV, including pH, surfactant concentration, equilibration time and temperature, were study and optimized; as well as its coupling to UFLC-ESI-MS/MS. Under optimized conditions, the resulting methodology was as follows: a 500 μL aliquot of human plasma was diluted with 2 mL deionized water in a 10 mL centrifuge tube. A 500 μL aliquot Triton X-114 5% w/v was added and homogenized using a vortex stirrer. The resulting cloudy solution was kept at 65 °C for 20 min for promoting the condensation of surfactant micelles. Then it was centrifuged at 3000 x g for 5 min for separation of the surfactant-rich phase. After discarding the aqueous supernatant, 400 μL ACN were added to the remaining surfactant rich phase and centrifuged in order to precipitate proteins and separate them. A 150 μL aliquot of the supernatant was transferred to 2 mL vial and further diluted with 400 μL deionized water. A 30 μL aliquot of the so-prepared solution was injected and analyzed into the UFLC-MS/MS. The method detection limits for ABC, EFV, 3TC and NFV under optimized conditions were 31, 77, 57 and 21 ng mL-1, respectively. The RSD% for the studied analytes were < 15%, except at the LOQ, which were < 19%. Recovery values ranged from 81 to 107%. The proposed methodology was successfully applied for the analysis of ABC, EFV, 3TC and NFV in human plasma within the concentration range of 43-6816, 125-4992, 81-3248 and 49-7904 ng mL-1, respectively. Under optimized working conditions the proposed analytical methodology meets standard requirements of international guidelines, which makes it suitable for pharmacokinetic studies of the four ARV, as well as for therapeutic monitoring of HIV patients.

      PubDate: 2015-08-23T09:09:29Z
      DOI: 10.1016/j.ancr.2015.08.002
      Issue No: Vol. 6 (2015)
       
  • Expanded metabolite coverage of Saccharomyces cerevisiae extract through
           improved chloroform/methanol extraction and tert-butyldimethylsilyl
           derivatization

    • Authors: Sakda Khoomrung; Jose L. Martinez; Stefan Tippmann; Suwanee Jansa-Ard; Marieke F. Buffing; Raffaele Nicastro; Jens Nielsen
      Pages: 9 - 16
      Abstract: Publication date: Available online 19 October 2015
      Source:Analytical Chemistry Research
      Author(s): Sakda Khoomrung, Jose L. Martinez, Stefan Tippmann, Suwanee Jansa-Ard, Marieke F. Buffing, Raffaele Nicastro, Jens Nielsen
      We present an improved extraction and derivatization protocol for GC-MS analysis of amino/non-amino acids in Saccharomyces cerevisiae. Yeast cells were extracted with chloroform: aqueous-methanol (1:1, v/v) and the resulting non-polar and polar extracts combined and dried for derivatization. Polar and non-polar metabolites were derivatized using tert-butyldimethylsilyl (t-BDMS) dissolved in acetonitrile. Using microwave treatment of the samples, the derivatization process could be completed within 2 hr (from >20h of the conventional method), providing fully derivatized of metabolites that contain multiple derivatizable organic functional groups. This results in a single derivative from one metabolite, leading to increased accuracy and precision for identification and quantification of the method. Analysis of combined fractions allowed the method to expand the coverage of detected metabolites from polar metabolites i.e. amino acids, organic acids and non-polar metabolites i.e. fatty alcohols and long-chain fatty acids which are normally non detectable. The recoveries of extraction method was found at 88±4 %, RSD, N=3) using anthranilic acid as an internal standard. The method promises to be a very useful tool in various aspects of biotechnological applications i.e. development of cell factories, metabolomics profiling, metabolite identification, 13C-labelled flux analysis or semi-quantitative analysis of metabolites in yeast samples.
      Graphical abstract image

      PubDate: 2015-10-23T15:58:05Z
      DOI: 10.1016/j.ancr.2015.10.001
      Issue No: Vol. 6 (2015)
       
  • Facilitating the indirect detection of genomic DNA in an electrochemical
           DNA biosensor using magnetic nanoparticles and DNA ligase

    • Authors: Roozbeh Hushiarian; Nor Azah Yusof; Abdul Halim Abdullah; Shahrul Ainliah Alang Ahmad; Sabo Wada Dutse
      Pages: 17 - 25
      Abstract: Publication date: Available online 21 October 2015
      Source:Analytical Chemistry Research
      Author(s): Roozbeh Hushiarian, Nor Azah Yusof, Abdul Halim Abdullah, Shahrul Ainliah Alang Ahmad, Sabo Wada Dutse
      A common problem in applying biosensors for the detection of genomic DNA is detecting short sequences in large amounts of long double stranded DNA. A gold electrode modified with a conductive nanocomposite, poly(3,4-ethylene-dioxythiophen), and gold nanoparticles was functionalized with 2,6-Pyridinedicarboxylic acid. Immobilization of a 20-mer DNA probe as the bioreceptor was successfully carried out via a peptide bond on the surface of the modified electrode. Two segments of 15 and 20 base probes were designed and named as Capture and Reporter probes respectively. The 20-mer Reporter probe was complementary to the bioreceptor and the 15-mer Capture probe was designed to bind on to the surface of the iron oxide magnetic nanoparticles. A 35-base Target DNA complementary to the Capture and the Reporter probes was used as Template in the ligation process, with the ligation between the Reporter and Capture probes mediated by T4 ligase. Iron oxide magnetic nanoparticles functionalized with carboxylic groups on their surface synthesized in a new method were attached to the 15-mer Capture probe. After the denaturation of the final ligation product, the separation of the attached probes was carried out using 5 gauss permanent magnets in a three step washing procedure in TE buffer. The hybridization of the DNA bioreceptor and the Reporter probe attached to the Capture probe-Fe3O4 was monitored via oxidation and reduction of the new redox marker (ruthenium complex) intercalated into the double helix. This technique was found to be reliably repeatable. The indirect detection of genomic DNA using this method is significantly improved and showed high efficiency in small amounts of samples with the detection limit of 5.37×10-14 M.
      Graphical abstract image

      PubDate: 2015-10-23T15:58:05Z
      DOI: 10.1016/j.ancr.2015.10.004
      Issue No: Vol. 6 (2015)
       
  • Rapid detection of fluoride in potable water using a novel fluorogenic
           compound 7-O-tert-butyldiphenylsilyl-4-methylcoumarin

    • Authors: Ravi Chavali; Naga Siva Kumar Gunda; Selvaraj Naicker; Sushanta K. Mitra
      Pages: 26 - 31
      Abstract: Publication date: Available online 19 October 2015
      Source:Analytical Chemistry Research
      Author(s): Ravi Chavali, Naga Siva Kumar Gunda, Selvaraj Naicker, Sushanta K. Mitra
      In the present work, we have synthesized a new water soluble colorless chemical compound 7-O-tert-butyldiphenylsilyl-4-methylcoumarin (TBDPSC) that releases fluorescent molecules imparting blue fluorescence to the solution, upon interaction with fluoride ions in water. The blue fluorescence can be visualized using simple hand held ultraviolet (UV) lamps. TBDPSC has excellent sensitivity and selectivity towards fluoride and our results indicate that fluoride concentrations as low as 0.2 mg/L can be accurately detected within a few seconds. Fluoride testing with TBDPSC is simple and rapid compared to the conventional methodologies without the requirement of trained personnel. Hence, the present fluoride detection method can be easily field deployable and particularly useful for monitoring water quality in limited resource communities.
      Graphical abstract image

      PubDate: 2015-10-23T15:58:05Z
      DOI: 10.1016/j.ancr.2015.10.003
      Issue No: Vol. 6 (2015)
       
  • Quantitative measurement of metal chelation by fourier transform infrared
           spectroscopy

    • Authors: Monika E. Miller; Lani P. McKinnon; Edward B. Walker
      Pages: 32 - 35
      Abstract: Publication date: Available online 23 October 2015
      Source:Analytical Chemistry Research
      Author(s): Monika E. Miller, Lani P. McKinnon, Edward B. Walker
      Nutritionally important minerals are more readily absorbed by living systems when complexed with organic acids, resulting in higher consumer demand and premium prices for these products. These chelated metals are produced by reaction of metal oxides and acids in aqueous solution. However, unreacted dry blends are sometimes misrepresented as metal chelates, when in reality they are only simple mixtures of the reactants typically used to synthesize them. This practice has increased interest in developing analytical methods that are capable of measuring the extent of metal chelation for quality control and regulatory compliance. We describe a novel method to rapidly measure the percent chelation of these two acids with calcium, magnesium, and zinc. Utilization of attenuated total reflectance (FTIR-ATR) provides for the direct, rapid measurement of solid samples. The inclusion of an internal standard allows independent determination of either free or chelated acids from integrated areas in a single spectrum.
      Graphical abstract image

      PubDate: 2015-10-23T15:58:05Z
      DOI: 10.1016/j.ancr.2015.10.002
      Issue No: Vol. 6 (2015)
       
  • Direct Electron Transfer Biosensor for Hydrogen Peroxide Carrying
           Nanocomplex Composed of Horseradish Peroxidase and Au-nanoparticle -
           Characterization and Application to Bienzyme Systems

    • Authors: Yusuke Okawa; Naoto Yokoyama; Yoshinori Sakai; Fumiyuki Shiba
      Pages: 1 - 8
      Abstract: Publication date: Available online 23 May 2015
      Source:Analytical Chemistry Research
      Author(s): Yusuke Okawa , Naoto Yokoyama , Yoshinori Sakai , Fumiyuki Shiba
      A reagentless electrochemical biosensor for hydrogen peroxide was fabricated. The sensor carries a monolayer of nanocomplex composed of horseradish peroxidase and Au-nanoparticle, and responds to hydrogen peroxide through the highly efficient direct electron transfer at a mild electrode potential without any soluble mediator. Formation of the nanocomplex was studied with visible spectroscopy and size exclusion chromatography. The sensor performance was analyzed based on a hydrodynamic electrochemical technique and enzyme kinetics. The sensor was applied to fabrication of sensors for glucose and uric acid through further modification of the nanocomplex-carrying electrode with the corresponding hydrogen peroxide-generating oxidases, glucose oxidase and urate oxidase, respectively.
      Graphical abstract image

      PubDate: 2015-05-25T01:12:38Z
      DOI: 10.1016/j.ancr.2015.05.001
      Issue No: Vol. 5 (2015)
       
  • Analytical protocols for the determination of sulphur compounds
           characteristic of the metabolism of Chlorobium limicola

    • Authors: A. Aliboni; L. Lona; C. Felici; N. Corsaro; G. Izzo; E. De Luca
      Pages: 9 - 13
      Abstract: Publication date: Available online 3 June 2015
      Source:Analytical Chemistry Research
      Author(s): A. Aliboni , L. Lona , C. Felici , N. Corsaro , G. Izzo , E. De Luca
      Chlorobium limicola belongs to the green sulphur bacteria that has a potential for technological applications such as biogas clean up oxidising hydrogen sulphide to elemental sulphur through photosynthetic process. In the present work, analytical methods are described for the determination of different sulphur species in C. limicola cultures – sulphide by GC-FPD, sulphate by ionic HPLC and elemental sulphur by RP HPLC. The latter method eliminates the need for chloroform extraction of water suspensions of elemental sulphur. Data from sulphide and elemental sulphur analyses have been compared with ones coming from more traditional analytical methodologies.
      Graphical abstract image

      PubDate: 2015-06-07T11:55:53Z
      DOI: 10.1016/j.ancr.2015.05.002
      Issue No: Vol. 5 (2015)
       
  • Amperometric detection of carbohydrates based on the glassy carbon
           electrode modified with gold nano-flake layer

    • Authors: Huy Du Nguyen; T. Thuy Luyen Nguyen; Khac Manh Nguyen; Anh Mai Nguyen; Quoc Hien Nguyen
      Pages: 14 - 20
      Abstract: Publication date: Available online 12 June 2015
      Source:Analytical Chemistry Research
      Author(s): Huy Du Nguyen , T. Thuy Luyen Nguyen , Khac Manh Nguyen , Anh Mai Nguyen , Quoc Hien Nguyen
      An electro-deposition approach was established to incorporate the gold nano-flakes onto the glassy carbon electrode in electrochemical cells (nano-Au/GC/ECCs). Using pulsed amperometric detection (PAD) without any gold oxidation for cleaning (non-oxidative PAD), the nano-Au/GC/ECCs were able to maintain their activity for oxidizing of carbohydrates in a normal alkaline medium. The reproducibility of peak area was about 2 relative standard deviation (RSD,%) for 6 consecutive injections. A dynamic range of carbohydrates was obtained over a concentration range of 5–80mgL−1 and the limits of detection (LOD) were of 2mgL−1 for fructose and lactose and 1mgL−1 for glucose and galactose. Moreover, the nano-Au/GC/ECC using the non-oxidative PAD was able to combine with the internal standard method for determination of lactose in fresh cow milk sample.
      Graphical abstract image

      PubDate: 2015-06-20T11:54:49Z
      DOI: 10.1016/j.ancr.2015.06.001
      Issue No: Vol. 5 (2015)
       
  • Optical sensing of 3-phenoxybenzoic acid as a pyrethroid pesticides
           exposure marker by surface imprinting polymer capped on manganese-doped
           zinc sulfide quantum dots

    • Authors: Vivek Pandey; Abhishek Chauhan; Gajanan Pandey; Mohana Krishna Reddy Mudiam
      Pages: 21 - 27
      Abstract: Publication date: Available online 19 June 2015
      Source:Analytical Chemistry Research
      Author(s): Vivek Pandey , Abhishek Chauhan , Gajanan Pandey , Mohana Krishna Reddy Mudiam
      The present communication deals with the synthesis of luminescent Mn-doped ZnS quantum dots (QDs) anchored to surface imprinted polymer for the optical sensing of 3-phenoxy benzoic acid (3-PBA) in urine samples. The combination of sensing and surface functionalization not only improves the selectivity of the method, but also increases the optosensing ability of the material for non-phosphorescent substances. The developed material was utilized for the selective and sensitive detection of 3-PBA in urine samples. The proposed method shows good linearity with a regression coefficient (R 2) of 0.98. The limit of detection was found to be 0.117μM. The method has an acceptable precision and accuracy which are found to be less than 8% and 80–90% respectively at three different concentrations. The quenching constant of quantum dot-molecular imprinted polymer was found to be 3.4 times higher to that of the quantum dot-non imprinted polymer (QD-NIP) as calculated by Stern–Volmer equation. The sensing method developed has shown immense utility to detect 3-PBA in complex biological samples like urine.
      Graphical abstract image

      PubDate: 2015-06-20T11:54:49Z
      DOI: 10.1016/j.ancr.2015.06.002
      Issue No: Vol. 5 (2015)
       
  • Feasibility study of calibration strategy for direct quantitative
           measurement of K and Mg in plant material by laser-induced breakdown
           spectrometry

    • Authors: Daniel Menezes Silvestre; Felipe Miranda Barbosa; Bruno Teves Aguiar; Flávio Oliveira Leme; Cassiana Seimi Nomura
      Pages: 28 - 33
      Abstract: Publication date: Available online 26 June 2015
      Source:Analytical Chemistry Research
      Author(s): Daniel Menezes Silvestre , Felipe Miranda Barbosa , Bruno Teves Aguiar , Flávio Oliveira Leme , Cassiana Seimi Nomura
      The calibration and quantitative measurement is the “Achilles heel” of the LIBS technique. This paper deals with a method developed for the direct measurement of K and Mg in plant samples. Instrumental parameters were optimized and the best condition found was a 50 μm spot size, 10 Hz laser repetition rate, 75 accumulated laser pulses with 25 mJ/pulse and 0.25 μs of delay time. For method calibration, the use of synthetic standard calibrating material prepared by the addition of increasing concentrations of K and Mg in wood, filter paper and babassu mesocarp was proposed in order to assess the feasibility of using these various matrices in plant samples analysis. The limits of detection of proposed method were 2-30 and 6-27 μg g-1 for K e Mg, respectively. The use of the carbon emission wavelength at 247.856 nm was used as internal standard to improve the analytical results. Certified reference materials of plants were used to check the accuracy of the proposed method and recovery around 82 and 100% were obtained in all cases.

      PubDate: 2015-06-26T12:24:55Z
      DOI: 10.1016/j.ancr.2015.06.003
      Issue No: Vol. 5 (2015)
       
  • Towards broadening thermospray flame furnace atomic absorption
           spectrometry: Influence of organic solvents on the analytical signal of
           magnesium

    • Authors: Ezequiel Morzan; Jorge Stripeikis; Mabel Tudino
      Pages: 1 - 7
      Abstract: Publication date: June 2015
      Source:Analytical Chemistry Research, Volume 4
      Author(s): Ezequiel Morzan , Jorge Stripeikis , Mabel Tudino
      This study demonstrates the influence of the solvent when thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS) is employed for the determination of elements of low volatility, taking magnesium (Mg) as leading case. Several organic solvents/water solutions of different characteristics (density, surface tension, viscosity, etc.) and proportions were employed for the TS-FF-AAS analytical determination. To this end, solutions containing methanol, ethanol and isopropanol in water were assayed. Measurements were performed at different acetylene/air ratios of the combustion flame and then, the corresponding response surfaces were obtained. Methanol/water 75% v/v as carrier and a fuel rich flame were found as the most sensitive alternative. In the light of these findings and in order to explain the changes on the analytical signal, the influence of the solvent characteristics, the sample droplet size and the redox environment was studied. An estimation of the temperature of different zones of the heated flame furnace based on a modified signal ratio pyrometry method was analyzed for comparative purposes. A full discussion is provided throughout the paper. Once obtained the best conditions for analysis, Mg was determined in samples of effervescent vitamin tablets comparing two different solvents. The tablets were dissolved in methanol/water 75% v/v and ethanol/water 75% v/v and then, directly introduced in the TS device. The methanol/water 75% v/v dissolution yielded a slightly higher sensitivity when compared to ethanol/water and thus, the latter was selected due to its lower toxicity. The obtained figures of merit are: LOD (3σb): 0.021mgL−1; LOQ (10σb): 0.068mgL−1, sensitivity: 0.086Lmg−1; RSD%: 3.55, dynamic linear range 0.068–5mgL−1. Comparison of the results was performed by flame atomic absorption spectrometry (FAAS), showing a good agreement (95% confidence level, n =5). Whilst the FAAS approach needed sample mineralization as no complete solubility was attained with both alcohol/water solvents, TS allowed direct introduction of the sample with an excellent recovery of the analyte after spiking. The whole TS procedure was more economic (lower amount of reagents and wastings, lower time of operation) and faster (60h−1 sampling throughput) than FAAS. Nonetheless, the main objective of this work is to show that an analytical signal different from zero can be obtained for Mg via TS by simply choosing the adequate operational variables that allow an optimization of the mass transfer of the analyte into the atomizer and a favorable dynamics of desolvation/atomization. This approach could broad TS analytical capabilities to other elements of lower volatility as it is shown here for the case of Mg.
      Graphical abstract image Highlights

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2015.02.002
      Issue No: Vol. 4 (2015)
       
  • Gas sensing properties of indium–gallium–zinc–oxide gas sensors in
           different light intensity

    • Authors: Kuen-Lin Chen; Guo-Jhen Jiang; Kai-Wei Chang; Jan-Han Chen; Chiu-Hsien Wu
      Pages: 8 - 12
      Abstract: Publication date: June 2015
      Source:Analytical Chemistry Research, Volume 4
      Author(s): Kuen-Lin Chen , Guo-Jhen Jiang , Kai-Wei Chang , Jan-Han Chen , Chiu-Hsien Wu
      We have successfully observed the change in indium–gallium–zinc–oxide (IGZO) gas sensor sensitivity by controlling the light emitting diode (LED) power under the same gas concentrations. The light intensity dependence of sensor properties is discussed. Different LED intensities obviously affected the gas sensor sensitivity, which decays with increasing LED intensity. High LED intensity decreases not only gas sensor sensitivity but also the response time (T 90), response time constant (τ res) and the absorption rate per second. Low intensity irradiated to sensor causes high sensitivity, but it needs larger response time. Similar results were also observed in other kinds of materials such as TiO2. According to the results, the sensing properties of gas sensors can be modulated by controlling the light intensity.
      Graphical abstract image

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2015.03.001
      Issue No: Vol. 4 (2015)
       
  • Stripping voltammetric detection of nephrotoxic drug cefitizoxime in
           wastewater

    • Authors: Jahangir Ahmad Rather; Rajeev Jain
      Pages: 13 - 19
      Abstract: Publication date: June 2015
      Source:Analytical Chemistry Research, Volume 4
      Author(s): Jahangir Ahmad Rather , Rajeev Jain
      The objective of the present work is to develop the stripping voltammetric method for determination of nephrotoxic drug cefitizoxime in pharmaceutical formulation and its application to wastewater analysis. Solubilized system of different surfactants viz. cationic, anionic and non-ionic influences the electrochemical response of cefitizoxime. Solubilized system of CTAB containing cefitizoxime enhanced the peak current while anionic and non-ionic showed an opposite effect. The current signal due to the reduction process is a function of concentration of the cefitizoxime, pH of medium, type of surfactant and accumulation time at electrode surface. The proposed SWCAdSV (Squarewave Cathodic Adsorptive Voltammtery) and DPCAdSV (Differential Pulse Cathodic Adsorptive Voltammetry) are linear over concentration range 1.732–6.901μg/mL and 4.792–30.672μg/mL with detection limit of 0.76ng/mL and 2.63ng/mL, respectively. The method is successfully applied for determination of cefitizoxime in pharmaceutical formulation and wastewater with mean percentage recovery of 99.73% and 98.51%, respectively.

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2015.03.002
      Issue No: Vol. 4 (2015)
       
  • Development and validation of a high performance liquid chromatography
           method for oligodeoxynucleotides determination in a novel coagel-based
           formulation

    • Authors: Gabriela V. Ullio-Gamboa; Juan M. Llabot; María F. Sanchez-Vallecillo; Belkys A. Maletto; Santiago D. Palma; Daniel A. Allemandi
      Pages: 20 - 24
      Abstract: Publication date: June 2015
      Source:Analytical Chemistry Research, Volume 4
      Author(s): Gabriela V. Ullio-Gamboa , Juan M. Llabot , María F. Sanchez-Vallecillo , Belkys A. Maletto , Santiago D. Palma , Daniel A. Allemandi
      The therapeutic benefit of phosphorothioate oligodeoxynucleotides (PS-ODN) containing immune stimulatory sequences has been demonstrated in animal models of cancer and infection. Several tools are available for the determination of these oligonucleotides in biological samples and pharmaceutical preparations, including UV spectroscopy, dye binding, isotopic tracing, capillary gel electrophoresis (CGE), hybridization-based enzyme-linked immunosorbent assay (ELISA), and chromatography techniques. However, due to inter-assay variability and accuracy problems associated with the afore mentioned methods, we have developed and validated an isocratic high performance liquid chromatographic (HPLC) for analytical determination of PS-ODN containing unmethylated CpG motifs (CpG-ODN). Validation under Food and Drug Administration (FDA) guidelines of the analytical parameters include: linearity (r2 0.9996), LOD (0.86μg/ml) and LOQ (6.25μg/ml), intra (0.19–3.37%) and inter-day precision (0.63–3.75%) expressed as relative standard deviation (RSD), and robustness parameters (less than 2.80%). Using this method, recoveries ranging from 89.9% to 99.9% were obtained. Thus, this method provides a simple, sensitive, precise and reproducible examination which can be readily adapted for the assessment of CpG-ODN in different pharmaceutical preparations.

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2015.03.003
      Issue No: Vol. 4 (2015)
       
  • A submicron mesoporous silica for the determination of organosulphur in
           sea water

    • Authors: Awad Aqeel Al-rashdi
      Pages: 25 - 32
      Abstract: Publication date: June 2015
      Source:Analytical Chemistry Research, Volume 4
      Author(s): Awad Aqeel Al-rashdi
      Organosulphur compounds were determined in seawater samples by gas chromatography using a pulse flame detection method. The analytical method involved the use of octyl-diol mesoporous silica as a replacement for organic solvents in the extraction and pre-concentration of organosulphur compounds from seawater samples based on the solid phase dispersion extraction technique. The detection limits were in the range 0.6–2ngS/L, while the repeatability and reproducibility were 7–12% and 13–16% respectively. Relative standard deviations (%) for recovery of n-ethanthiol (n-EtSH), di-n-ethyl sulphide (n-Et2S) and di-n-ethyl disulphide (n-Et2S2) in spiked water samples were in the range 2.2–6.6% (at 0.5μg/L level). Under the experimental conditions used, quantitative extraction of n-EtSH, n-Et2S and n-Et2S2 was achieved with recoveries ranging from 93% to 99%. The procedure has been successfully applied to organosulphur determination in seawater samples collected from Jeddah beach (West of Saudi Arabia).

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2015.04.001
      Issue No: Vol. 4 (2015)
       
  • Development and applications of spectrophotometric methods for
           quantitative determination of caroverine in pharmaceutical pure and tablet
           formulations

    • Authors: Asad Raza; Tariq Mahmood Ansari
      Pages: 33 - 38
      Abstract: Publication date: June 2015
      Source:Analytical Chemistry Research, Volume 4
      Author(s): Asad Raza , Tariq Mahmood Ansari
      This paper describes two simple and novel analytical methods by using spectrophotometric technique for the determination of caroverine a spasmolytic drug in pharmaceutical formulations. The first (A) is a direct method in which analysis of the pure drug was carried out at its λ max 304nm in ethanol solvent. The method was linear from 0.5 to 18μg/ml with correlation coefficient of 0.999 and molar absorptivity of 5.55×104 Lmole−1 cm−1. Limit of detection and limit of quantification were 0.44 and 1.47μg/ml. While the second method (B) is based on the charge transfer reaction between caroverine as n-electron donor and 7,7,8,8-tetracyanoquinodimethane (TCNQ) as pi-acceptor resulting in highly colored stable complex, which showed maximum absorption band at wavelength of 525nm. The thermodynamic parameters were calculated as association constant K CT of 7.53×104 mol−1 and Gibbs free energy ΔG° of −6.72kJmol−1. Different variables affecting the charge transfer reaction were carefully studied and optimized. At the optimum reaction conditions, Beer’s law was obeyed in a concentration range of 1–35μgml−1 with molar absorptivity of 1.17×104 Lmole−1 cm−1 and correlation coefficient of 0.9999. The proposed methods were validated according to ICH guidelines.

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2015.03.004
      Issue No: Vol. 4 (2015)
       
  • Cross-platform detection of epigenetic modifications from extracted
           chromatin in leucocytes from blood

    • Authors: Zhongwu Zhou; II-Hood Cho; Zhi Shan; Joseph Irudayaraj
      Pages: 39 - 44
      Abstract: Publication date: Available online 30 April 2015
      Source:Analytical Chemistry Research
      Author(s): Zhongwu Zhou , II-Hood Cho , Zhi Shan , Joseph Irudayaraj
      Chromatin contains valuable epigenetic information comprising of both DNA and post translational histone modifications. Traditionally, detection of epigenetic modifications on DNA and histone proteins requires different and elaborate preparation steps. In this study we report on a facile and unique approach for the simultaneous detection and quantification of epigenetic modifications on DNA and histone proteins in one sample preparation step. Our novel one-pot technique consists of a chromatin extraction step from whole blood using bi-functional carboxyl-functionalized magnetic nanoparticles as solid-phase absorbents. Leucocytes enrichment from blood and chromatin extracted from the leucocytes by lysis was achieved with the same carboxyl-functionalized magnetic nanoparticles. The isolated chromatin was then eluted from the magnetic nanoparticles with PBS 1×. Using the eluted chromatin as substrate, we developed a quantitative method for simultaneous detection of epigenetic modifications on DNA and histone proteins by a biotin–streptavidin mediated enzyme-based immunosorbent assay (two-step EIA) on a 96-well plate. The simultaneous detection of epigenetic modifications on DNA and histone was validated by DNA-based EIA and histone-based Western blotting analysis performed separately with conventional protocols. By coupling cell separation and chromatin purification with a simple detection module, the global epigenetic information could be evaluated in less than 8h in leucocytes from blood. Our simplified cross-platform approach can be used by most laboratories for multiplex detection, uses non-hazardous materials and could be integrated with microfabrication methods for onchip analysis.
      Graphical abstract image

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2015.04.002
      Issue No: Vol. 4 (2015)
       
  • Analysis for commonly prescribed non-sedating antihistamines

    • Authors: Michael E. El-Kommos; Samia M. El-Gizawy; Noha N. Atia; Noha M. Hosny
      Pages: 1 - 12
      Abstract: Publication date: March 2015
      Source:Analytical Chemistry Research, Volume 3
      Author(s): Michael E. El-Kommos , Samia M. El-Gizawy , Noha N. Atia , Noha M. Hosny
      A comprehensive review with 185 references for the analysis of commonly prescribed members of an important class of drugs, non-sedating antihistamines (NSAs), is presented. The review covers most of the methods described for the analysis of cetirizine (CTZ), ebastine (EBS), fexofenadine (FXD), ketotifen (KET) and loratadine (LOR) in pure forms, in different pharmaceutical dosage forms and in biological fluids. The review covers the period from 1991 till now.
      Graphical abstract image

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2014.11.003
      Issue No: Vol. 3 (2015)
       
  • Screening of polychlorinated biphenyls in insulating oil using a
           microfluidic based pretreatment and immunoassay

    • Authors: Arata Aota; Yasumoto Date; Shingo Terakado; Naoya Ohmura
      Pages: 13 - 19
      Abstract: Publication date: March 2015
      Source:Analytical Chemistry Research, Volume 3
      Author(s): Arata Aota , Yasumoto Date , Shingo Terakado , Naoya Ohmura
      Polychlorinated biphenyls (PCBs) are persistent organic pollutants in insulating oil of a large number of transformers. A rapid and economical analytical method to detect PCB contamination is still required. To address this issue, we propose here the first microfluidic screening method for PCB contamination in insulating oil. The insulating oil was pretreated using a multilayer capillary column and a microfluidic liquid–liquid partitioning. PCBs in the pretreated oil were measured using a microfluidic kinetic exclusion assay. In order to detect PCBs with high sensitivity, conditions of the microfluidic kinetic exclusion assay were optimized. Measurements were rapidly completed (within 43min). The measurement range was estimated to be 0.26–3.3mg/kg defined as the relative absorbance from 20% to 80%. The screening performance (false positive and false negative rates) was tested on fifty real oil samples; results about these tests were discussed in detail, especially suitable cutoff by comparing with the data analyzed using high-resolution-gas-chromatography/high-resolution-mass-spectrometry. Finally, the screening performance was confirmed using our proposed stochastic screening model. A cutoff of 0.3 to judge as positive is suitable considering the risk of the PCB release into the environment.
      Graphical abstract image

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2014.11.002
      Issue No: Vol. 3 (2015)
       
  • Unambiguous evaluation of the relative photolysis rates of nitro indolinyl
           protecting groups critical for brain network studies

    • Authors: Richard L. Comitz; Yannick P. Ouedraogo; Nasri Nesnas
      Pages: 20 - 25
      Abstract: Publication date: March 2015
      Source:Analytical Chemistry Research, Volume 3
      Author(s): Richard L. Comitz , Yannick P. Ouedraogo , Nasri Nesnas
      Nitrated indolinyl photoprotecting groups are crucial tools extensively used in the study of neuronal signal transduction. Mononitrated photolabile protecting groups have been used effectively, however, recent advances in the introduction of a second nitro group have shown improvement in the photo efficiency of neurotransmitter (agonist) release, albeit, to varying extents, depending on the assessment methods employed. An unambiguous method is discussed based on Nuclear Magnetic Resonance (NMR), which is shown to be an effective technique in the relative overall rate comparison amongst varying nitrated protecting groups. Mononitrated and dinitrated photolabile protecting groups such as CDNI-Glu and MNI-Glu are used as an example to assess the relative value of adding a second nitro group in photoactive cage designs. Using this technique, it was shown that the second nitro group in CDNI systems enhances the overall relative rate of photocleavage by a factor of 5.8. This reported method can also be used to unambiguously determine relative rate of agonist photorelease.
      Graphical abstract image

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2014.11.001
      Issue No: Vol. 3 (2015)
       
  • Evaluation of organic and inorganic compounds levels of red wines
           processed from Pinot Noir grapes

    • Authors: Heli Sirén; Kimmo Sirén; Juhani Sirén
      Pages: 26 - 36
      Abstract: Publication date: March 2015
      Source:Analytical Chemistry Research, Volume 3
      Author(s): Heli Sirén , Kimmo Sirén , Juhani Sirén
      Pinot Noir red wines made by malolactic fermentation were studied for studying differences in their chemical profiles with help of a wide spectrum of grape-based and other chemical compounds used in winemaking. Determinations were made with capillary electrophoresis, liquid chromatography, and spectrometry to investigate carbohydrates, organic acids, aldehydes, anthocyanins, phenolic compounds, inorganic anions, and metals. In addition, tot-N, tot-S, and tot-P in the wines were examined. The wine products showed different profiles of carbohydrates, organic acids, phenolic compounds, and minerals. Especially, saccharose (max. 0.21g/L), rhamnose (max. 0.45g/L), fructose (max. 1.9g/L), and phosphate (max 1.4g/L) quantities were extremely high in some wines. The results also showed that yeast fermentation in winemaking agitated high production of lactic (max 5.7g/L) and tartaric (max 1.7g/L) acids. The red wines processed by cold maceration and natural fermentation gave similar profiles. Only one of the Pinot Noir wines entirely differentiated from the others with comparison of carbohydrates and organic acids.
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      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2014.10.002
      Issue No: Vol. 3 (2015)
       
  • An improved extraction method of rapeseed oil sample preparation for the
           subsequent determination in it of azole class fungicides by gas
           chromatography

    • Authors: Mikhail F. Zayats; Sergey M. Leschev; Marina A. Zayats
      Pages: 37 - 45
      Abstract: Publication date: March 2015
      Source:Analytical Chemistry Research, Volume 3
      Author(s): Mikhail F. Zayats , Sergey M. Leschev , Marina A. Zayats
      The distribution of 19 azole class pesticides in hexane/aqueous–organic mixtures systems and rapeseed oil (or oil solution in hexane)/organic solvents has been studied at 20±1°C. The distribution constants (P) and coefficients (D) between hydrocarbon and polar phase are calculated. It is found that all the studied pesticides are hydrophobic, i.e., in hexane–water system log P ≫0. Replacement of water by organic solvents results in sharp log P falling, and their values become negative. It is revealed that solutions of strong inorganic acids in anhydrous acetonitrile extract azole class pesticides from hexane and vegetable oils most fully and selectively. In particular, the acidification of acetonitrile causes a drop of D values in 50–2000 times for the majority of the studied pesticides. This phenomenon was used for the development of the improved technique for the quantitative analysis of a widely used azole class pesticides, which can be presented at trace levels in rapeseed oil. The proposed methodology is based on dissociation extraction (DE) of azoles using perchloric acid in anhydrous acetonitrile, with following clean-up of acetonitrile extract from organic impurities by hexane and aqueous solution of dipotassium hydrogen orthophosphate, and final GC–ECD (gas chromatography with electron capture detection) determination of azole fungicides. The values of obtained recoveries were between 85% and 115% with RSD values below 10%. The obtained limits of quantitation, ranged from 3.0 to 300μgkg−1, are below the maximum residue levels (MRLs) set by the European Union for the majority of pesticides. The developed method was successfully applied to different rapeseed oil samples.
      Graphical abstract image

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2014.11.004
      Issue No: Vol. 3 (2015)
       
  • Quantitative compositional analysis of heparin using exhaustive heparinase
           digestion and strong anion exchange chromatography

    • Authors: Pierre Mourier; Pascal Anger; Céline Martinez; Fréderic Herman; Christian Viskov
      Pages: 46 - 53
      Abstract: Publication date: March 2015
      Source:Analytical Chemistry Research, Volume 3
      Author(s): Pierre Mourier , Pascal Anger , Céline Martinez , Fréderic Herman , Christian Viskov
      Heparin is a linear sulfated polysaccharide widely used therapeutically as an anticoagulant. It is also the starting material for manufacturing low-molecular-weight heparins (LMWH). Quality control of heparin and LMWH is critical to ensure the safety and therapeutic activity of the final product. However due to their complex and heterogeneous structure, orthogonal analytical techniques are needed to characterize the building blocks of heparin. One of the state-of-the-art methods for heparin analysis is based on complete enzymatic digestion using a mixture of heparinases I, II, and III, followed by the separation of the resulting oligosaccharides by liquid chromatography. The European Pharmacopoeia strong anion-exchange chromatographic method, used to quantify 1,6-anhydro derivatives in enoxaparin, is here applied to the analysis of the heparin building blocks. Their quantification, namely the determination of their average w/w percentage in the heparin chain, is obtained after identification of all components including glycoserine derivatives and 3-O sulfated di- and tetrasaccharides. This work therefore provides a comprehensive overview of the building blocks of unfractionated heparin, including those chemically modified by the manufacturing process, either within the polysaccharide chain or at its reducing end.

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2014.12.001
      Issue No: Vol. 3 (2015)
       
  • Analysis of cave atmospheres by comprehensive two-dimensional gas
           chromatography (GC×GC) with flame ionization detection (FID)

    • Authors: Ryan C. Blase; Edward L. Patrick; Joseph N. Mitchell; Mark Libardoni
      Pages: 54 - 62
      Abstract: Publication date: March 2015
      Source:Analytical Chemistry Research, Volume 3
      Author(s): Ryan C. Blase , Edward L. Patrick , Joseph N. Mitchell , Mark Libardoni
      In this paper, we describe a simple method for sampling, pre-concentrating, and separating volatile and semi-volatile components from two different cave atmospheres. Sampling is performed by capturing a volume of cave atmosphere in a Tedlar bag or Suma canister for sample storage and transport back to the laboratory. Loading a portion of the sample on a multi-bed sorption trap allows for sample pre-concentration prior to separation and detection of components on a comprehensive two-dimensional gas chromatograph (GC×GC). Comparison of two Texas caves reveals the power of comprehensive two-dimensional gas chromatography (GC×GC) for volatile separation and detection, and to our knowledge marks the first use of GC×GC for the analysis of cave atmospheres. Analysis of the results revealed 138 and 146 chromatographic signals over an S/N threshold of 500 and direct comparison of the two samples revealed 50 identical chromatographic signals. This study is a first step toward demonstrating the ability of GC×GC to separate the complex volatiles and semi-volatiles in the cave atmosphere as a fingerprinting tool.

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2014.09.002
      Issue No: Vol. 3 (2015)
       
  • Micellar high performance liquid chromatographic determination of flunixin
           meglumine in bulk, pharmaceutical dosage forms, bovine liver and kidney

    • Authors: Fathalla F. Belal; Sawsan A. Abd El-Razeq; Manal M. Fouad; Fatma A. Fouad
      Pages: 63 - 69
      Abstract: Publication date: March 2015
      Source:Analytical Chemistry Research, Volume 3
      Author(s): Fathalla F. Belal , Sawsan A. Abd El-Razeq , Manal M. Fouad , Fatma A. Fouad
      A simple, sensitive and rapid liquid chromatographic method was developed and validated for the analysis of flunixin meglumine (flunixin-M) in bulk, pharmaceutical dosage forms, bovine liver and kidney. Analytical separation was performed in less than 4min using a C18 column with UV detection at 284nm. A micellar solution composed of 0.15M sodium dodecyl sulphate, 8% n-butanol and 0.3% triethylamine in 0.02M phosphoric acid buffered at pH 7.0 was used as the mobile phase. The method was fully validated in accordance with the International Conference on Harmonization (ICH) guidelines. The limit of detection and the limit of quantitation were 0.02 and 0.06μgmL−1, respectively. The recoveries obtained were in range of 95.58–106.94% for bovine liver and kidney. High extraction efficiency was obtained without matrix interference in the extraction process and in the subsequent chromatographic determination. The method showed good repeatability, linearity and sensitivity according to the evaluation of the validation parameters.

      PubDate: 2015-05-04T09:11:27Z
      DOI: 10.1016/j.ancr.2014.12.003
      Issue No: Vol. 3 (2015)
       
  • Electrochemical behavior of kaempferol and its determination in presence
           of quercetin employing multi-walled carbon nanotube modified carbon paste
           electrode

    • Authors: Riyaz Ahmad Dar; Gowhar Ahmad Naikoo; Israr Ul Hassan; Ahmad M.H Shaikh; Ashwini Kumar Srivastavd
      Abstract: Publication date: Available online 2 December 2015
      Source:Analytical Chemistry Research
      Author(s): Riyaz Ahmad Dar, Gowhar Ahmad Naikoo, Israr Ul Hassan, Ahamad M.H. Shaikh
      The electrochemical behavior of kaempferol was investigated by cyclic voltammetry (CV) and square wave voltammetry (SWV) at plane and multiwalled carbon nanotubes modified carbon paste electrode (MWCNTs/CPE). Kaempferol produces an anodic peak at MWCNTs modified CPE with a quasi-reversible nature in phosphate buffer of pH 7.73. The oxidized species of kaempferol was found to be stable (Ipa/Ipc ≈1) over scan rates of 100∼600 mVs-1. The same electrode was also found to catalyze the electrode oxidation of quercetin in presence of kaempferol under similar conditions which enabled the simultaneous determination of kaempferol and quercetin. Linearity of peak currents (Ip) vs. concentrations of kaempferol and quercetin was found in the range of 6.72 x 10-9 M to 40.34 x 10-9 M with a detection limit of 2.90 x 10-9 M for kaempferol and 13.0 x 10-9 M to 50.9 x 10-9 M with a detection limit of 3.5 x 10-9 M for quercetin using fast and sensitive SWV. The developed method has been applied for the quantitative analysis of kaempferol in corms and petals of Indian traditional medicine saffron (Crocus sativus) using a phosphate buffer of pH 7.73 and the average percent recoveries obtained are 99.84 and 99.26, respectively.
      Graphical abstract image

      PubDate: 2015-12-02T11:00:26Z
      DOI: 10.1016/j.ancr.2015.08.001
       
  • Evaluation of Glycidyl Methacrylate-based Monolith Functionalized with
           Weak Anion Exchange Moiety inside 0.5 mm i.d. Column for Liquid
           Chromatographic Separation of DNA

    • Authors: Aprilia Nur; Tasfiyati Elvina Dhiaul Iftitah Setyawan Purnomo Sakti Akhmad
      Abstract: Publication date: Available online 30 November 2015
      Source:Analytical Chemistry Research
      Author(s): Aprilia Nur Tasfiyati, Elvina Dhiaul Iftitah, Setyawan Purnomo Sakti, Akhmad Sabarudin
      In this study, the organic polymer monolith was developed as a weak anion exchanger column in high performance liquid chromatography for DNA separation. Methacrylate-based monolithic column was prepared in microbore silicosteel column (100 x 0.5 mm i.d.) by in-situ polymerization reaction using glycidyl methacrylate as monomer; ethylene dimethacrylate as crosslinker; 1-propanol, 1,4-butanediol, and water as porogenic solvents, with the presence of initiator α,α’-azobisisobutyronitrile (AIBN). The monolith matrix was modified with diethylamine to create weak anion exchanger via ring opening reaction of epoxy groups. The morphology of the monolithic column was studied by SEM. The properties of the monolithic column, such as permeability, mechanical stability, binding capacity and pore size distribution, were characterized in detail. From the results of the characterization, monoliths poly-(GMA-co-EDMA) with total monomer percentage (%T) 40 and crosslinker percentage (%C) 25 was found to be the ideal composition of monomer and crosslinker. It has good mechanical stability and high permeability, adequate molecular recognition sites (represented with binding capacity value of 36 mg ml-1), and has relatively equal proportion of flow-through pore and mesopores (37.2% and 41.1% respectively). Poly-(GMA-co-EDMA) with %T 40 and %C 25 can successfully separate oligo(dT)12-18 and 50 bp DNA ladder with good resolution.
      Graphical abstract image

      PubDate: 2015-12-02T11:00:26Z
       
 
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