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Publisher: Elsevier   (Total: 3030 journals)

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Showing 1 - 200 of 3030 Journals sorted alphabetically
AASRI Procedia     Open Access   (Followers: 15)
Academic Pediatrics     Hybrid Journal   (Followers: 20, SJR: 1.402, h-index: 51)
Academic Radiology     Hybrid Journal   (Followers: 16, SJR: 1.008, h-index: 75)
Accident Analysis & Prevention     Partially Free   (Followers: 79, SJR: 1.109, h-index: 94)
Accounting Forum     Hybrid Journal   (Followers: 22, SJR: 0.612, h-index: 27)
Accounting, Organizations and Society     Hybrid Journal   (Followers: 27, SJR: 2.515, h-index: 90)
Achievements in the Life Sciences     Open Access   (Followers: 4)
Acta Anaesthesiologica Taiwanica     Open Access   (Followers: 5, SJR: 0.338, h-index: 19)
Acta Astronautica     Hybrid Journal   (Followers: 303, SJR: 0.726, h-index: 43)
Acta Automatica Sinica     Full-text available via subscription   (Followers: 3)
Acta Biomaterialia     Hybrid Journal   (Followers: 25, SJR: 2.02, h-index: 104)
Acta Colombiana de Cuidado Intensivo     Full-text available via subscription  
Acta de Investigación Psicológica     Open Access   (Followers: 2)
Acta Ecologica Sinica     Open Access   (Followers: 8, SJR: 0.172, h-index: 29)
Acta Haematologica Polonica     Free   (SJR: 0.123, h-index: 8)
Acta Histochemica     Hybrid Journal   (Followers: 3, SJR: 0.604, h-index: 38)
Acta Materialia     Hybrid Journal   (Followers: 196, SJR: 3.683, h-index: 202)
Acta Mathematica Scientia     Full-text available via subscription   (Followers: 5, SJR: 0.615, h-index: 21)
Acta Mechanica Solida Sinica     Full-text available via subscription   (Followers: 9, SJR: 0.442, h-index: 21)
Acta Oecologica     Hybrid Journal   (Followers: 9, SJR: 0.915, h-index: 53)
Acta Otorrinolaringologica (English Edition)     Full-text available via subscription   (Followers: 1)
Acta Otorrinolaringológica Española     Full-text available via subscription   (Followers: 3, SJR: 0.311, h-index: 16)
Acta Pharmaceutica Sinica B     Open Access   (Followers: 2)
Acta Poética     Open Access   (Followers: 4)
Acta Psychologica     Hybrid Journal   (Followers: 21, SJR: 1.365, h-index: 73)
Acta Sociológica     Open Access  
Acta Tropica     Hybrid Journal   (Followers: 5, SJR: 1.059, h-index: 77)
Acta Urológica Portuguesa     Open Access  
Actas Dermo-Sifiliograficas     Full-text available via subscription   (Followers: 4)
Actas Dermo-Sifiliográficas (English Edition)     Full-text available via subscription   (Followers: 3)
Actas Urológicas Españolas     Full-text available via subscription   (Followers: 3, SJR: 0.383, h-index: 19)
Actas Urológicas Españolas (English Edition)     Full-text available via subscription   (Followers: 2)
Actualites Pharmaceutiques     Full-text available via subscription   (Followers: 5, SJR: 0.141, h-index: 3)
Actualites Pharmaceutiques Hospitalieres     Full-text available via subscription   (Followers: 4, SJR: 0.112, h-index: 2)
Acupuncture and Related Therapies     Hybrid Journal   (Followers: 4)
Ad Hoc Networks     Hybrid Journal   (Followers: 11, SJR: 0.967, h-index: 57)
Addictive Behaviors     Hybrid Journal   (Followers: 15, SJR: 1.514, h-index: 92)
Addictive Behaviors Reports     Open Access   (Followers: 5)
Additive Manufacturing     Hybrid Journal   (Followers: 7, SJR: 1.039, h-index: 5)
Additives for Polymers     Full-text available via subscription   (Followers: 20)
Advanced Drug Delivery Reviews     Hybrid Journal   (Followers: 120, SJR: 5.2, h-index: 222)
Advanced Engineering Informatics     Hybrid Journal   (Followers: 11, SJR: 1.265, h-index: 53)
Advanced Powder Technology     Hybrid Journal   (Followers: 16, SJR: 0.739, h-index: 33)
Advances in Accounting     Hybrid Journal   (Followers: 8, SJR: 0.299, h-index: 15)
Advances in Agronomy     Full-text available via subscription   (Followers: 15, SJR: 2.071, h-index: 82)
Advances in Anesthesia     Full-text available via subscription   (Followers: 24, SJR: 0.169, h-index: 4)
Advances in Antiviral Drug Design     Full-text available via subscription   (Followers: 3)
Advances in Applied Mathematics     Full-text available via subscription   (Followers: 6, SJR: 1.054, h-index: 35)
Advances in Applied Mechanics     Full-text available via subscription   (Followers: 10, SJR: 0.801, h-index: 26)
Advances in Applied Microbiology     Full-text available via subscription   (Followers: 21, SJR: 1.286, h-index: 49)
Advances In Atomic, Molecular, and Optical Physics     Full-text available via subscription   (Followers: 16, SJR: 3.31, h-index: 42)
Advances in Biological Regulation     Hybrid Journal   (Followers: 4, SJR: 2.277, h-index: 43)
Advances in Botanical Research     Full-text available via subscription   (Followers: 3, SJR: 0.619, h-index: 48)
Advances in Cancer Research     Full-text available via subscription   (Followers: 26, SJR: 2.215, h-index: 78)
Advances in Carbohydrate Chemistry and Biochemistry     Full-text available via subscription   (Followers: 9, SJR: 0.9, h-index: 30)
Advances in Catalysis     Full-text available via subscription   (Followers: 5, SJR: 2.139, h-index: 42)
Advances in Cellular and Molecular Biology of Membranes and Organelles     Full-text available via subscription   (Followers: 12)
Advances in Chemical Engineering     Full-text available via subscription   (Followers: 24, SJR: 0.183, h-index: 23)
Advances in Child Development and Behavior     Full-text available via subscription   (Followers: 10, SJR: 0.665, h-index: 29)
Advances in Chronic Kidney Disease     Full-text available via subscription   (Followers: 8, SJR: 1.268, h-index: 45)
Advances in Clinical Chemistry     Full-text available via subscription   (Followers: 28, SJR: 0.938, h-index: 33)
Advances in Colloid and Interface Science     Full-text available via subscription   (Followers: 18, SJR: 2.314, h-index: 130)
Advances in Computers     Full-text available via subscription   (Followers: 16, SJR: 0.223, h-index: 22)
Advances in Developmental Biology     Full-text available via subscription   (Followers: 11)
Advances in Digestive Medicine     Open Access   (Followers: 4)
Advances in DNA Sequence-Specific Agents     Full-text available via subscription   (Followers: 5)
Advances in Drug Research     Full-text available via subscription   (Followers: 22)
Advances in Ecological Research     Full-text available via subscription   (Followers: 39, SJR: 3.25, h-index: 43)
Advances in Engineering Software     Hybrid Journal   (Followers: 25, SJR: 0.486, h-index: 10)
Advances in Experimental Biology     Full-text available via subscription   (Followers: 7)
Advances in Experimental Social Psychology     Full-text available via subscription   (Followers: 38, SJR: 5.465, h-index: 64)
Advances in Exploration Geophysics     Full-text available via subscription   (Followers: 3)
Advances in Fluorine Science     Full-text available via subscription   (Followers: 8)
Advances in Food and Nutrition Research     Full-text available via subscription   (Followers: 41, SJR: 0.674, h-index: 38)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 14)
Advances in Genetics     Full-text available via subscription   (Followers: 15, SJR: 2.558, h-index: 54)
Advances in Genome Biology     Full-text available via subscription   (Followers: 11)
Advances in Geophysics     Full-text available via subscription   (Followers: 6, SJR: 2.325, h-index: 20)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 18, SJR: 0.906, h-index: 24)
Advances in Heterocyclic Chemistry     Full-text available via subscription   (Followers: 8, SJR: 0.497, h-index: 31)
Advances in Human Factors/Ergonomics     Full-text available via subscription   (Followers: 22)
Advances in Imaging and Electron Physics     Full-text available via subscription   (Followers: 2, SJR: 0.396, h-index: 27)
Advances in Immunology     Full-text available via subscription   (Followers: 33, SJR: 4.152, h-index: 85)
Advances in Inorganic Chemistry     Full-text available via subscription   (Followers: 9, SJR: 1.132, h-index: 42)
Advances in Insect Physiology     Full-text available via subscription   (Followers: 3, SJR: 1.274, h-index: 27)
Advances in Integrative Medicine     Hybrid Journal   (Followers: 4)
Advances in Intl. Accounting     Full-text available via subscription   (Followers: 4)
Advances in Life Course Research     Hybrid Journal   (Followers: 7, SJR: 0.764, h-index: 15)
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: 16, SJR: 1.645, h-index: 45)
Advances in Mathematics     Full-text available via subscription   (Followers: 10, SJR: 3.261, h-index: 65)
Advances in Medical Sciences     Hybrid Journal   (Followers: 5, SJR: 0.489, h-index: 25)
Advances in Medicinal Chemistry     Full-text available via subscription   (Followers: 5)
Advances in Microbial Physiology     Full-text available via subscription   (Followers: 4, SJR: 1.44, h-index: 51)
Advances in Molecular and Cell Biology     Full-text available via subscription   (Followers: 21)
Advances in Molecular and Cellular Endocrinology     Full-text available via subscription   (Followers: 10)
Advances in Molecular Toxicology     Full-text available via subscription   (Followers: 6, SJR: 0.324, h-index: 8)
Advances in Nanoporous Materials     Full-text available via subscription   (Followers: 3)
Advances in Oncobiology     Full-text available via subscription   (Followers: 3)
Advances in Organometallic Chemistry     Full-text available via subscription   (Followers: 15, SJR: 2.885, h-index: 45)
Advances in Parallel Computing     Full-text available via subscription   (Followers: 7, SJR: 0.148, h-index: 11)
Advances in Parasitology     Full-text available via subscription   (Followers: 7, SJR: 2.37, h-index: 73)
Advances in Pediatrics     Full-text available via subscription   (Followers: 20, SJR: 0.4, h-index: 28)
Advances in Pharmaceutical Sciences     Full-text available via subscription   (Followers: 14)
Advances in Pharmacology     Full-text available via subscription   (Followers: 13, SJR: 1.718, h-index: 58)
Advances in Physical Organic Chemistry     Full-text available via subscription   (Followers: 7, SJR: 0.384, h-index: 26)
Advances in Phytomedicine     Full-text available via subscription  
Advances in Planar Lipid Bilayers and Liposomes     Full-text available via subscription   (Followers: 3, SJR: 0.248, h-index: 11)
Advances in Plant Biochemistry and Molecular Biology     Full-text available via subscription   (Followers: 8)
Advances in Plant Pathology     Full-text available via subscription   (Followers: 5)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Protein Chemistry     Full-text available via subscription   (Followers: 18)
Advances in Protein Chemistry and Structural Biology     Full-text available via subscription   (Followers: 17, SJR: 1.5, h-index: 62)
Advances in Psychology     Full-text available via subscription   (Followers: 56)
Advances in Quantum Chemistry     Full-text available via subscription   (Followers: 5, SJR: 0.478, h-index: 32)
Advances in Radiation Oncology     Open Access  
Advances in Small Animal Medicine and Surgery     Hybrid Journal   (Followers: 1, SJR: 0.1, h-index: 2)
Advances in Space Research     Full-text available via subscription   (Followers: 332, SJR: 0.606, h-index: 65)
Advances in Structural Biology     Full-text available via subscription   (Followers: 7)
Advances in Surgery     Full-text available via subscription   (Followers: 6, SJR: 0.823, h-index: 27)
Advances in the Study of Behavior     Full-text available via subscription   (Followers: 28, SJR: 1.321, h-index: 56)
Advances in Veterinary Medicine     Full-text available via subscription   (Followers: 14)
Advances in Veterinary Science and Comparative Medicine     Full-text available via subscription   (Followers: 12)
Advances in Virus Research     Full-text available via subscription   (Followers: 5, SJR: 1.878, h-index: 68)
Advances in Water Resources     Hybrid Journal   (Followers: 42, SJR: 2.408, h-index: 94)
Aeolian Research     Hybrid Journal   (Followers: 5, SJR: 0.973, h-index: 22)
Aerospace Science and Technology     Hybrid Journal   (Followers: 304, SJR: 0.816, h-index: 49)
AEU - Intl. J. of Electronics and Communications     Hybrid Journal   (Followers: 8, SJR: 0.318, h-index: 36)
African J. of Emergency Medicine     Open Access   (Followers: 4, SJR: 0.344, h-index: 6)
Ageing Research Reviews     Hybrid Journal   (Followers: 7, SJR: 3.289, h-index: 78)
Aggression and Violent Behavior     Hybrid Journal   (Followers: 390, SJR: 1.385, h-index: 72)
Agri Gene     Hybrid Journal  
Agricultural and Forest Meteorology     Hybrid Journal   (Followers: 15, SJR: 2.18, h-index: 116)
Agricultural Systems     Hybrid Journal   (Followers: 29, SJR: 1.275, h-index: 74)
Agricultural Water Management     Hybrid Journal   (Followers: 36, SJR: 1.546, h-index: 79)
Agriculture and Agricultural Science Procedia     Open Access  
Agriculture and Natural Resources     Open Access   (Followers: 1)
Agriculture, Ecosystems & Environment     Hybrid Journal   (Followers: 48, SJR: 1.879, h-index: 120)
Ain Shams Engineering J.     Open Access   (Followers: 5, SJR: 0.434, h-index: 14)
Air Medical J.     Hybrid Journal   (Followers: 3, SJR: 0.234, h-index: 18)
AKCE Intl. J. of Graphs and Combinatorics     Open Access   (SJR: 0.285, h-index: 3)
Alcohol     Hybrid Journal   (Followers: 9, SJR: 0.922, h-index: 66)
Alcoholism and Drug Addiction     Open Access   (Followers: 5)
Alergologia Polska : Polish J. of Allergology     Full-text available via subscription   (Followers: 1)
Alexandria Engineering J.     Open Access   (Followers: 1, SJR: 0.436, h-index: 12)
Alexandria J. of Medicine     Open Access  
Algal Research     Partially Free   (Followers: 7, SJR: 2.05, h-index: 20)
Alkaloids: Chemical and Biological Perspectives     Full-text available via subscription   (Followers: 3)
Allergologia et Immunopathologia     Full-text available via subscription   (Followers: 1, SJR: 0.46, h-index: 29)
Allergology Intl.     Open Access   (Followers: 5, SJR: 0.776, h-index: 35)
ALTER - European J. of Disability Research / Revue Européenne de Recherche sur le Handicap     Full-text available via subscription   (Followers: 6, SJR: 0.158, h-index: 9)
Alzheimer's & Dementia     Hybrid Journal   (Followers: 45, SJR: 4.289, h-index: 64)
Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring     Open Access   (Followers: 5)
Alzheimer's & Dementia: Translational Research & Clinical Interventions     Open Access   (Followers: 3)
American Heart J.     Hybrid Journal   (Followers: 45, SJR: 3.157, h-index: 153)
American J. of Cardiology     Hybrid Journal   (Followers: 47, SJR: 2.063, h-index: 186)
American J. of Emergency Medicine     Hybrid Journal   (Followers: 34, SJR: 0.574, h-index: 65)
American J. of Geriatric Pharmacotherapy     Full-text available via subscription   (Followers: 6, SJR: 1.091, h-index: 45)
American J. of Geriatric Psychiatry     Hybrid Journal   (Followers: 14, SJR: 1.653, h-index: 93)
American J. of Human Genetics     Hybrid Journal   (Followers: 32, SJR: 8.769, h-index: 256)
American J. of Infection Control     Hybrid Journal   (Followers: 25, SJR: 1.259, h-index: 81)
American J. of Kidney Diseases     Hybrid Journal   (Followers: 31, SJR: 2.313, h-index: 172)
American J. of Medicine     Hybrid Journal   (Followers: 48, SJR: 2.023, h-index: 189)
American J. of Medicine Supplements     Full-text available via subscription   (Followers: 3)
American J. of Obstetrics and Gynecology     Hybrid Journal   (Followers: 174, SJR: 2.255, h-index: 171)
American J. of Ophthalmology     Hybrid Journal   (Followers: 51, SJR: 2.803, h-index: 148)
American J. of Ophthalmology Case Reports     Open Access   (Followers: 2)
American J. of Orthodontics and Dentofacial Orthopedics     Full-text available via subscription   (Followers: 6, SJR: 1.249, h-index: 88)
American J. of Otolaryngology     Hybrid Journal   (Followers: 22, SJR: 0.59, h-index: 45)
American J. of Pathology     Hybrid Journal   (Followers: 23, SJR: 2.653, h-index: 228)
American J. of Preventive Medicine     Hybrid Journal   (Followers: 21, SJR: 2.764, h-index: 154)
American J. of Surgery     Hybrid Journal   (Followers: 32, SJR: 1.286, h-index: 125)
American J. of the Medical Sciences     Hybrid Journal   (Followers: 13, SJR: 0.653, h-index: 70)
Ampersand : An Intl. J. of General and Applied Linguistics     Open Access   (Followers: 5)
Anaerobe     Hybrid Journal   (Followers: 4, SJR: 1.066, h-index: 51)
Anaesthesia & Intensive Care Medicine     Full-text available via subscription   (Followers: 52, SJR: 0.124, h-index: 9)
Anaesthesia Critical Care & Pain Medicine     Full-text available via subscription   (Followers: 3)
Anales de Cirugia Vascular     Full-text available via subscription  
Anales de Pediatría     Full-text available via subscription   (Followers: 2, SJR: 0.209, h-index: 27)
Anales de Pediatría (English Edition)     Full-text available via subscription  
Anales de Pediatría Continuada     Full-text available via subscription   (SJR: 0.104, h-index: 3)
Analytic Methods in Accident Research     Hybrid Journal   (Followers: 2, SJR: 2.577, h-index: 7)
Analytica Chimica Acta     Hybrid Journal   (Followers: 38, SJR: 1.548, h-index: 152)
Analytical Biochemistry     Hybrid Journal   (Followers: 154, SJR: 0.725, h-index: 154)
Analytical Chemistry Research     Open Access   (Followers: 7, SJR: 0.18, h-index: 2)
Analytical Spectroscopy Library     Full-text available via subscription   (Followers: 10)
Anesthésie & Réanimation     Full-text available via subscription  
Anesthesiology Clinics     Full-text available via subscription   (Followers: 21, SJR: 0.421, h-index: 40)
Angiología     Full-text available via subscription   (SJR: 0.124, h-index: 9)
Angiologia e Cirurgia Vascular     Open Access  
Animal Behaviour     Hybrid Journal   (Followers: 143, SJR: 1.907, h-index: 126)
Animal Feed Science and Technology     Hybrid Journal   (Followers: 5, SJR: 1.151, h-index: 83)
Animal Reproduction Science     Hybrid Journal   (Followers: 5, SJR: 0.711, h-index: 78)
Annales d'Endocrinologie     Full-text available via subscription   (SJR: 0.394, h-index: 30)
Annales d'Urologie     Full-text available via subscription  
Annales de Cardiologie et d'Angéiologie     Full-text available via subscription   (SJR: 0.177, h-index: 13)
Annales de Chirurgie de la Main et du Membre Supérieur     Full-text available via subscription  
Annales de Chirurgie Plastique Esthétique     Full-text available via subscription   (Followers: 2, SJR: 0.354, h-index: 22)
Annales de Chirurgie Vasculaire     Full-text available via subscription   (Followers: 1)

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Journal Cover Analytical Chemistry Research
  [SJR: 0.18]   [H-I: 2]   [7 followers]  Follow
    
  This is an Open Access Journal Open Access journal
   ISSN (Print) 2214-1812
   Published by Elsevier Homepage  [3030 journals]
  • Nano clay Ni/NiO nanocomposite new sorbent for separation and
           preconcentration dibenzothiophene from crude prior to UV–vis
           spectrophotometery determination

    • Authors: Amineh Mashkuri; Asma Saljooqi; Zeinab Tohidiyan
      Pages: 47 - 51
      Abstract: Publication date: June 2017
      Source:Analytical Chemistry Research, Volume 12
      Author(s): Amineh Mashkuri, Asma Saljooqi, Zeinab Tohidiyan
      In this work, Ni/Ni nanoparticles were immobilized on modified nanoclay then, the resultant nanocomposite was used as a sorbent for separation of dibenzothiophene. The concentration of dibenzothiophene was determined with UV–vis spectrophotometry at 287 nm. Different parameters affecting the separation of dibenzothiophene such as: the ratio of Ni/NiO nanoparticles to nanoclay, amounts of Ni/NiO nanoparticles and nanoclay, stirring time of dibenzothiophene solution on the sorbent, type of eluent, eluent volume, elution time, stirring time for preparing the sorbent were optimized. The obtained results were shown quantitative desorption of dibenzothiophene performed using ethanol as eluent. A linear concentration range of 0.5–15 mg/L was obtained with a detection limit of 0.047 mg/mL. The sorbent capacity was found to be 32 mg/g. Relative standard deviation was ±1.4 for six replicated determination of 5 mg/g of dibenzothiophene. The optimized procedure was successfully used for a crude oil sample.

      PubDate: 2017-03-09T10:08:20Z
      DOI: 10.1016/j.ancr.2017.02.002
      Issue No: Vol. 12 (2017)
       
  • Comparative sensing of aldehyde and ammonia vapours on synthetic
           polypyrrole-Sn(IV)arsenotungstate nanocomposite cation exchange material

    • Authors: Asif Ali Khan; Rais Ahmad; Mohd. Zeeshan
      Abstract: Publication date: Available online 24 February 2017
      Source:Analytical Chemistry Research
      Author(s): Asif Ali Khan, Rais Ahmad, Mohd. Zeeshan
      Polypyrrole-Sn(IV)arsenotungstate (PPy-SnAT) conductive nanocomposite cation exchange have been synthesized by in-situ chemical oxidative polymerization of polypyrrole with Sn(IV)arsenotungstate (SnAT). PPy-SnAT nanocomposite was characterized by Fourier transform infra-red spectroscopy (FTIR), X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive x-ray (EDX) and thermogravimetric analysis (TGA). The ion exchange capacity (IEC) and DC electrical conductivity of nanocomposite was found to be 2.50 meq/g and 5.05 × 10−1 S/cm respectively. The nanocomposite showed appreciable isothermal stability in terms of DC electrical conductivity retention under ambient condition up to 130 °C. The nanocomposite cation exchange based sensor for detection of formaldehyde and ammonia vapours were fabricated at room temperature. It was revealed that the resistivity of the nanocomposite increases on exposure to higher percent concentration of ammonia and lower concentration of formaldehyde at room temperature (25 °C).
      Graphical abstract image

      PubDate: 2017-03-03T22:31:50Z
      DOI: 10.1016/j.ancr.2017.02.003
       
  • Preparation and characterization of a novel Co(II) optode based on polymer
           inclusion membrane

    • Authors: Faiz Bukhari Mohd Suah
      Abstract: Publication date: Available online 9 February 2017
      Source:Analytical Chemistry Research
      Author(s): Faiz Bukhari Mohd Suah
      A greener analytical procedure based on automated flow through system with an optical sensor is proposed for determination of Co(II). The flow through system consisted of polymer inclusion membrane (PIM) containing potassium thiocyanate (KSCN) that was placed between the measuring cell and fixed with optical sensor probe as an optical sensor for monitoring of Co(II) at 625 nm. In the presence of Co(II) ions, the colourless membrane changes to blue. The sensing membrane was prepared by incorporating SCN into a non plasticized PIM. The prepared PIM were found to be homogenous, transparent and mechanically stable. The optode shows reversible optical response in the range of 1.00 × 10−6 – 1.00 × 10−3 mol L−1 with detection limit of 6.10 × 10−7 mol L−1. The optode can be regenerated by using 0.1 mol L−1 of ethylenediaminetetraacetic acid (EDTA). The main parameters of the computer controlled flow system incorporating the flow-through optode, a multi-port selection valve and peristaltic pump were optimized too. The calculated Relative Standard Deviation (R.S.D) of the repeatability and reproducibility of the method are 0.76% and 4.73%, respectively. This green system has been applied to the determination of Co(II) in wastewater samples with reduced reagents and samples consumption and minimum waste generation.
      Graphical abstract image

      PubDate: 2017-02-10T15:07:03Z
      DOI: 10.1016/j.ancr.2017.02.001
       
  • A convenient colorimetric and ratiometric fluorescent probe for detection
           of cyanide based on BODIPY derivative in aqueous media

    • Authors: Yanhua Yu; Tingting Shu; Changzhi Dong
      Abstract: Publication date: Available online 1 February 2017
      Source:Analytical Chemistry Research
      Author(s): Yanhua Yu, Tingting Shu, Changzhi Dong
      A convenient colorimetric and ratiometric fluorescent probe based on BODIPY derivative for cyanide detection has been synthesized, whose structural contains a dicyanovinyl group used as a sensing unit. Among the tested analytes, such as CN−, F−, Cl−, Br−, I−, ClO4 −, AcO−, NO3 −, H2PO4 − HSO4 −, S2 − and N3 −, only CN− could react with dicyanovinyl moiety by nucleophilic addition, which disrupted the π-conjugation of the probe and hindered the intramolecular charge transfer (ICT), leading a blue shift of absorption and fluorescence spectrum and a concomitant color change from yellow to light pink. The detection limit of this probe was calculated to be 0.98 μM, which is lower than the maximum concentration in drinking water (1.9 μM) permitted by the World Health Organization (WHO). Moreover, the probe showed excellent selectivity and anti-interference ability towards CN− over other anions. The reaction mechanism was fully supported by 1H NMR and MS spectrum.

      PubDate: 2017-02-04T19:40:23Z
      DOI: 10.1016/j.ancr.2017.01.004
       
  • An assessment of different extraction and quantification methods of penta-
           and hexa-chlorobenzene from SRF fly-ash

    • Authors: Dimitris E. Balampanis; Frédéric Coulon; Nigel Simms; Philip Longhurst; Simon J.T. Pollard; Cecilia Fenech; Raffaella Villa
      Abstract: Publication date: Available online 26 January 2017
      Source:Analytical Chemistry Research
      Author(s): Dimitris E. Balampanis, Frédéric Coulon, Nigel Simms, Philip Longhurst, Simon J.T. Pollard, Cecilia Fenech, Raffaella Villa
      Highly chlorinated benzenes, produced in the presence of organic matter and chlorine, are considered PCDD/Fs precursors, and are used as cost and time convenient substitute indicators for the indirect measurement of the latter. In this study penta- and hexa-chlorobenzene are quantified for the determination of the organochloride load of fly ash from solid recovered fuel incineration. Some of the chlorobenzenes are formed under ‘de novo’ conditions, through heterogeneous (ash particles/flue gases) reactions and are therefore deeply incorporated within fly ash. Accelerated solvent extraction (ASE) and ultrasonic solvent extraction (USE), along with the equivalent clean-up methods suggested by literature were compared to traditional Soxhlet. The extraction efficiencies achieved were 83 ± 7.5% for Soxhlet, 111 ± 19% for PFE, and 67 ± 17% for ultrasonication. Soxhlet extraction and clean-up through a multilayer silica gel column gave more precise results compared to the other sample preparation methods. Furthermore, performance comparison of gas chromatography fitted with either a mass spectrometer operated in single ion monitoring mode (GC-MS-SIM), or electron capture detector (GC- ECD) highlighted that ECD can be used for measuring chlorobenzenes traces down to 0.21 ng g−1, when the equivalent LOQ for MS-SIM was 3.26 ng g−1. The results further suggest that ECD can provide better peak integration than MS-SIM in the detection of chlorobenzenes in fly ash extracts, due to the detector's sensitivity to halogenated compounds.
      Graphical abstract image

      PubDate: 2017-01-30T16:22:32Z
      DOI: 10.1016/j.ancr.2017.01.003
       
  • Multivariate methods for analysis of environmental reference materials
           using laser-induced breakdown spectroscopy

    • Authors: Shikha Awasthi; Rohit Kumar; Alamelu Devanathan; R. Acharya; A.K. Rai
      Abstract: Publication date: Available online 16 January 2017
      Source:Analytical Chemistry Research
      Author(s): Shikha Awasthi, Rohit Kumar, Alamelu Devanathan, R. Acharya, A.K. Rai
      Analysis of emission from laser-induced plasma has a unique capability for quantifying the major and minor elements present in any type of samples under optimal analysis conditions. Chemometric techniques are very effective and reliable tools for quantification of multiple components in complex matrices. The feasibility of laser-induced breakdown spectroscopy (LIBS) in combination with multivariate analysis was investigated for the analysis of environmental reference materials (RMs). In the present work, different (Certified/Standard) Reference Materials of soil and plant origin were analyzed using LIBS and the presence of Al, Ca, Mg, Fe, K, Mn and Si were identified in the LIBS spectra of these materials. Multivariate statistical methods (Partial Least Square Regression and Partial Least Square Discriminant Analysis) were employed for quantitative analysis of the constituent elements using the LIBS spectral data. Calibration models were used to predict the concentrations of the different elements of test samples and subsequently, the concentrations were compared with certified concentrations to check the authenticity of models. The non-destructive analytical method namely Instrumental Neutron Activation Analysis (INAA) using high flux reactor neutrons and high resolution gamma-ray spectrometry was also used for intercomparison of results of two RMs by LIBS.
      Graphical abstract image

      PubDate: 2017-01-22T15:43:00Z
      DOI: 10.1016/j.ancr.2017.01.001
       
  • Characterization of methyl ester compound of biodiesel from industrial
           liquid waste of crude palm oil processing

    • Authors: Maulidiyah; Muhammad Nurdin; Fetty Fatma; Muh. Natsir; Dwiprayogo Wibowo
      Abstract: Publication date: Available online 13 January 2017
      Source:Analytical Chemistry Research
      Author(s): Maulidiyah, Muhammad Nurdin, Fetty Fatma, Muh. Natsir, Dwiprayogo Wibowo
      The second generation of Bioenergy: a study of CPO liquid waste-based biodiesel production technology has been conducted. The aims of this study were to obtain biodiesel from Industrial liquid waste of CPO processing and to identify the kind of methyl-ester compound of the biodiesel. The production of biodiesel was applied in two steps of reactions; esterification reaction using H2SO4 and transesterification using CaO catalyst at 60 °C for 2 h. GC-MS analysis result showed that methyl ester from liquid waste of CPO contains methyl hexadecanoate 12.87%, methyl 9-octadecanoate 19.98%, methyl octadecanoate 5.71%, and methyl 8,11-octadecadienoate 10.22%.

      PubDate: 2017-01-14T15:27:34Z
      DOI: 10.1016/j.ancr.2017.01.002
       
  • Extraction and recovery of 2-butoxyethanol from aqueous phases containing
           high saline concentration

    • Authors: Katherine E. Manz; Kimberly E. Carter
      Pages: 1 - 7
      Abstract: Publication date: Available online 16 July 2016
      Source:Analytical Chemistry Research
      Author(s): Katherine E. Manz, Kimberly E. Carter
      Ethylene glycol monobutyl ether (EGBE), also known as 2-butoxyethanol (2-BE), has been identified as a contaminant in hydraulic fracturing fluids. In order to determine the presence of 2-BE in hydraulic fracturing chemical additives, a reliable method for recovering 2-BE from aqueous phases by liquid-liquid extraction combined with gas chromatography/mass spectrometry (GC/MS) was established. The liquid-liquid extraction method was applied to samples matrices containing various amounts of salt. Using methylene chloride for liquid-liquid extraction in a sample to solvent ratio of 1:3, ≥99% 2-BE recovery may be achieved with less than 5% standard error. The limit of detection was determined to be 0.957 mg L−1 2-BE. Accuracy was determined to be 2.58% and precision was determined using the coefficient of variation, which was 3.5%. The method was used to recover 2-BE in a hydraulic fracturing chemical additive called Revert Flow and to quantify the weight percent of 2-BE in the chemical additive. Weight percent of two additional components of Revert Flow, D-limonene and 1-butoxy-2-propanol, were also determined. We also used the method to determine the abiotic of 2-BE in water, which was 5.55 days. The persistence of 2-BE in hydraulic fracturing fluid was also investigated and determined that 2-BE is more persistent in this environment.

      PubDate: 2016-07-23T20:23:57Z
      DOI: 10.1016/j.ancr.2016.07.001
      Issue No: Vol. 9 (2016)
       
  • Chromogenic signaling of water traces by 1,8-naphthalohydrazone-anion
           complex in organic solvents

    • Authors: Veikko Uahengo; Bi Xiong; Ping Cai; Likius S. Daniel; Lydia Rhyman; Ponnadurai Ramasami
      Pages: 1 - 8
      Abstract: Publication date: Available online 3 March 2016
      Source:Analytical Chemistry Research
      Author(s): Veikko Uahengo, Bi Xiong, Ping Cai, Likius S. Daniel, Lydia Rhyman, Ponnadurai Ramasami
      A naphthalo-1, 8-bis[(2,4-dinitrophenyl)hydrazone] sensor (K) was synthesized and characterized using UV-vis, 1H NMR and fluorescence spectroscopy. The sensor showed strong colorimetric and spectral response upon the molar addition of acetate or fluoride ion (AcO- or F-) in acetonitrile. The complexed state (KF or KAcO) of the system showed significant reversibility properties, both in colour and spectra, upon the addition of small traces of water. Subsequently, in addition to sensing of fluoride or acetate ions, the complexed KF or KAcO adducts can be used in colorimetric signaling of water traces in different organic mediums. In order to have more understanding of the interaction between K and the anions, the study was supplemented using density functional theory computations.
      Graphical abstract image

      PubDate: 2016-03-08T13:02:48Z
      DOI: 10.1016/j.ancr.2016.03.001
      Issue No: Vol. 8 (2016)
       
  • Determination of Thermodynamic Parameters for Enolization Reaction of
           Malonic and Metylmalonic Acids by using Quartz Crystal Microbalance

    • Authors: Minoru Yoshimoto; Taishi Matsunaga; Mutsuo Tanaka; Shigeru Kurosawa
      Pages: 9 - 15
      Abstract: Publication date: Available online 19 March 2016
      Source:Analytical Chemistry Research
      Author(s): Minoru Yoshimoto, Taishi Matsunaga, Mutsuo Tanaka, Shigeru Kurosawa
      We investigated the process of a bromination reaction of malonic acid and methylmalonic acid in the Belousov-Zhabotinsky reaction by using a quartz crystal microbalance (QCM). The process involves an enolization reaction as a rate-determining step. We found that, in the step, the variation of Br2 concentration induced an exactly quantitative shift of a resonant frequency of the QCM, based on the change of the surface mass on the QCM and the solution viscosity and density. This new finding enabled us to estimate the reaction rate constants and the thermodynamic parameters of the enolization reaction due to a QCM measurement. The values measured by the QCM were in good agreement with those measured by a UV-spectrophotometer. As a result, we succeeded to develop a new measurement method of a nonlinear chemical reaction.
      Graphical abstract image

      PubDate: 2016-03-23T09:41:14Z
      DOI: 10.1016/j.ancr.2016.03.002
      Issue No: Vol. 8 (2016)
       
  • Quantification of 3α-hydroxytibolone in human plasma by high performance
           liquid chromatography coupled to electrospray ionization tandem mass
           spectrometry (HPLC-ESI-MS/MS): Application in a bioequivalence study in
           healthy postmenopausal volunteers

    • Authors: Lucas Azevedo Portela; Tiago Luders Laurito; Severino Beatrice; Elisa Perissutti; Gustavo D. Mendes; Ronilson Agnaldo Moreno; Gilberto De Nucci
      Pages: 16 - 25
      Abstract: Publication date: Available online 22 April 2016
      Source:Analytical Chemistry Research
      Author(s): Lucas Azevedo Portela, Tiago Luders Laurito, Severino Beatrice, Elisa Perissutti, Gustavo D. Mendes, Ronilson Agnaldo Moreno, Gilberto De Nucci
      A sensitive, specific and fast method to quantify 3α-hydroxytibolone in human plasma using deuterated 3α-hydroxytibolone (d5) as internal standard is described. The analyte and the internal standard were extracted from plasma (900 μL) by liquid-liquid extraction using ethyl ether/hexane (50/50, v/v) and ammonium hydroxide (50%). The extracts were analyzed by high performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry without derivatization. Chromatography was performed isocratically on a Gemini-NX™ C18 5 μm (150 × 4.6 mm i. d.) column. The method had a chromatographic run time of 3.75 min and a linear calibration curve over the range 1–100 ng/mL. The limit of quantification validated was 1 ng/mL. This method was used to assess the bioequivalence between two different tibolone oral formulations: Livolon (1.25 mg tablet) provided by Biolab Sanus Farmacêutica (Brazil), as the test formulation, and Libiam™ (1.25 mg tablet) produced by Libbs Farmacêutica (Brazil), as the reference formulation. A single 3.75 mg dose of each formulation was administered to 46 postmenopausal female healthy volunteers. The study was conducted in an open, randomized, two-period crossover balanced design with a 2 week washout interval between the doses. The 90% confidence interval for Cmax, AUC(0-last) and AUC(0-inf) individual test/reference ratios were 97.48–111.51, 95.35–103.20 and 96.42–103.86, respectively. It is concluded that Livolon (1.25 mg tablet) is bioequivalent to Libiam™ (1.25 mg tablet), with regards to both rate and extent of absorption.

      PubDate: 2016-04-27T09:16:55Z
      DOI: 10.1016/j.ancr.2016.04.002
      Issue No: Vol. 8 (2016)
       
  • Enriched surface acidity for surfactant-free suspensions of carboxylated
           carbon nanotubes purified by centrifugation

    • Authors: Elizabeth I. Braun; Rockford Draper; Paul Pantano
      Pages: 26 - 33
      Abstract: Publication date: Available online 11 April 2016
      Source:Analytical Chemistry Research
      Author(s): Elizabeth I. Braun, Rockford Draper, Paul Pantano
      It is well known that surfactant-suspended carbon nanotube (CNT) samples can be purified by centrifugation to decrease agglomerates and increase individually-dispersed CNTs. However, centrifugation is not always part of protocols to prepare CNT samples used in biomedical applications. Herein, using carboxylated multi-walled CNTs (cMWCNTs) suspended in water without a surfactant, we developed a Boehm titrimetric method for the analysis of centrifuged cMWCNT suspensions and used it to show that the surface acidity of oxidized carbon materials in aqueous cMWCNT suspensions was enriched by ∼40% by a single low-speed centrifugation step. This significant difference in surface acidity between un-centrifuged and centrifuged cMWCNT suspensions has not been previously appreciated and is important because the degree of surface acidity is known to affect the interactions of cMWCNTs with biological systems.
      Graphical abstract image

      PubDate: 2016-04-17T13:14:19Z
      DOI: 10.1016/j.ancr.2016.04.001
      Issue No: Vol. 8 (2016)
       
  • Rapid high-performance sample digestion of base metal ores using
           high-intensity infrared radiation with determination by nitrogen-based
           microwave plasma optical spectrometry

    • Authors: Yong Wang; Laura A. Baker; Erick Helmeczi; Ian D. Brindle
      Pages: 17 - 22
      Abstract: Publication date: Available online 13 February 2016
      Source:Analytical Chemistry Research
      Author(s): Yong Wang, Laura A. Baker, Erick Helmeczi, Ian D. Brindle
      Infrared sample digestion technology has been rapidly developed in recent years and its application and digestion performance on a variety of ores of base metals was assessed in this study, using a 6-channel infrared digester. Digestion times of 10 minutes or less were achieved for all base metal ores investigated, including oxides, sulfides, and silicates of Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, Ti, W, and Zn. Performance criteria for all samples were excellent, reflected in z values of less than 2 in all cases. Various acid digestion methods were developed for the selected ore samples under high intensity infrared radiation and delivered virtually complete recoveries of all of the elements of interest. Chromite, the notoriously refractory chromium ore was digested within 10 minutes and gave 100% recovery of chromium. These digestions were accomplished without resorting to perchloric acid and, for most sample types, without hydrofluoric acid, significantly improving the workplace safety for analysts. Between-channel variation of the analyte recoveries from the 6-channel unit were generally below 2%, suggesting that the digestion methods developed with this platform provide reproducible results to meet various sample preparation demands. The high speed and analyte recovery of these digestions makes this methodology especially attractive for prospectors and developers who demand rapid and reliable results from exploration samples.
      Graphical abstract image

      PubDate: 2016-02-13T19:23:28Z
      DOI: 10.1016/j.ancr.2016.02.002
      Issue No: Vol. 7 (2016)
       
  • Basic Characteristics of Quartz Crystal Sensor with Interdigitated
           Electrodes

    • Authors: Hiroshi Muramatsu; Maki Kawamura; Sachiko Tanabe; Masayuki Suda
      Pages: 23 - 30
      Abstract: Publication date: Available online 13 February 2016
      Source:Analytical Chemistry Research
      Author(s): Hiroshi Muramatsu, Maki Kawamura, Sachiko Tanabe, Masayuki Suda
      This paper describes basic characteristics of the quartz crystal sensor with interdigitated electrodes (IDE quartz crystal sensor) which is for simultaneous monitoring of mass, viscosity, conductivity and dielectric changes of liquids or thin films. As the IDE quartz crystal sensor has three terminals for a pair of IDEs on the one side and a counter electrode on the other side, the resonance properties have been analyzed using the electrical equivalent circuit models and measured experimentally for all connecting types of electrode pairs. The IDE quartz crystal has shown clear resonance curves for calculating the resonance frequency and resonance resistance values as well as normal quartz crystal in the air and in contact with liquid. Small shifts in the resonance frequency and resonance resistance depending on the connecting types have been obtained and analyzed using the equivalent circuit models. We have found the integrated quartz crystal and IDE sensors could be monitored simultaneously by only one impedance analyzer. Finally, two types of measuring systems have been demonstrated for continuous measuring methods.

      PubDate: 2016-02-13T19:23:28Z
      DOI: 10.1016/j.ancr.2016.02.001
      Issue No: Vol. 7 (2016)
       
  • Sensors based on Ag-loaded hematite (α-Fe2O3) nanoparticles for methyl
           mercaptan detection at room temperature

    • Authors: Daniel Garcia; Gino Picasso; Pilar Hidalgo; Henrique E.M. Peres; Rosario Sun Kou; Josué M. Gonçalves
      Abstract: Publication date: Available online 19 December 2016
      Source:Analytical Chemistry Research
      Author(s): Daniel Garcia, Gino Picasso, Pilar Hidalgo, Henrique E.M. Peres, Rosario Sun Kou, Josué M. Gonçalves
      Sensors based on Ag/α-Fe2O3 nanoparticles have been prepared by the coprecipitation method for sensing methyl mercaptan at room temperature. X-ray diffraction patterns of samples matched perfectly with characteristic peaks of hematite with no peaks assigned to Ag even at the highest concentration. STEM images and EDX analysis revealed the presence of Ag nanoparticles (from 2 to 5 nm) which were highly dispersed onto α-Fe2O3 surface with an Ag/Fe ratio from 0.014 to 0.099. The Ag nanoparticles were deposited on the hematite surface. Sensing tests of Ag-loaded hematite nanoparticles showed much higher response signal than the unmodified sensor. Hematite loaded with 3%(Wt) Ag showed the highest response with a linear dependence from 20 to 80 ppm. The sensor also depicted a good selectivity and stability during 4 days with short recovery time. The high dispersion of reduced Ag evaluated by XPS analysis played an important chemical role in the sensing mechanism that favored the contact of CH3SH with oxygen.
      Graphical abstract image

      PubDate: 2016-12-25T05:02:10Z
      DOI: 10.1016/j.ancr.2016.12.001
       
  • Enhancement of the atomic absorbance of Cr, Zn, Cd, and Pb in metal
           furnace atomic absorption spectrometry using absorption tubes

    • Authors: Yuya Koike; Kenta Hagiwara; Toshihiro Nakamura
      Abstract: Publication date: Available online 21 November 2016
      Source:Analytical Chemistry Research
      Author(s): Yuya Koike, Kenta Hagiwara, Toshihiro Nakamura
      Trace amounts of Cr, Zn, Cd, and Pb were determined by metal furnace atomic absorption spectrometry using absorption tubes. Various absorption tubes were designed as roof- and tube-types, and fixed above the metal furnace in order to extend the light path length. Aqueous standards and samples were injected in the metal furnace and atomized in a metal atomizer with an absorption tube (6 cm length, 15.5 mm diameter). The used of an absorption tube resulted in an enhancement of the atomic absorbance. The ratios of absorbance values with and without the roof- and tube-type absorption tubes were 1.33 and 1.11 for Cr; 1.42 and 1.99 for Zn; 1.66 and 1.98 for Cd; and 1.31 and 1.16 for Pb, respectively. The use of an absorption tube was effective for Zn and Cd analysis, as the absorbance values for these low boiling point metals doubled. The proposed method was successfully applied in the determination of Zn in tap water.
      Graphical abstract image

      PubDate: 2016-11-26T09:18:11Z
      DOI: 10.1016/j.ancr.2016.11.004
       
  • Structural identification and estimation of Rosuvastatin calcium related
           impurities in Rosuvastatin calcium tablet dosage form

    • Authors: Chamarthi R.P. Kishore; G.V. Krishna Mohan
      Abstract: Publication date: Available online 17 November 2016
      Source:Analytical Chemistry Research
      Author(s): Chamarthi R.P. Kishore, G.V. Krishna Mohan
      A precise, accurate, specific, linear, rugged and robust analytical method was developed and validated for estimation of process and degradant impurities of Rosuvastatin calcium (RSC) in Rosuvastatin calcium tablets. 150 mm length column, 4.6 mm diameter and 3.5μ particle size with C18 stationary phase and pH3.0 phosphate buffer as mobile phase. Column was maintained at 30 °C.All impurities are monitored at 248 nm.Impurities are separated in gradient elution mode. All degradant impurities of RSC (Anti-isomer, 5-ketoacid, lactone and meglumine adduct), process impurity (Imp-A) are well separated. Unknown impurity (Meglumine adduct) formed during stability studies was isolated using preparative HPLC and structure was characterized by NMR and Mass spectrometry (LC-MS and HRMS) studies. Method is capable of separating and estimating all the degradant and process impurities.

      PubDate: 2016-11-19T08:58:47Z
      DOI: 10.1016/j.ancr.2016.11.002
       
  • Optimization of a method based on micro-matrix solid-phase dispersion
           (micro-MSPD) for the determination of PCBs in mussel samples

    • Authors: Nieves Carro; Laura Vilas; Isabel García; María Ignacio; Ana M. Mouteira
      Abstract: Publication date: Available online 17 November 2016
      Source:Analytical Chemistry Research
      Author(s): Nieves Carro, Laura Vilas, Isabel García, María Ignacio, Ana M. Mouteira
      This paper reports the development and optimization of micro-matrix solid-phase dispersion (micro-MSPD) of nine polychlorinated biphenyls (PCBs) in mussel samples (Mytilus galloprovincialis) by using a two-level factorial design. Four variables (amount of sample, anhydrous sodium sulphate, Florisil and solvent volume) were considered as factors in the optimization process. The results suggested that only the interaction between the amount of anhydrous sodium sulphate and the solvent volume was statistically significant for the overall recovery of a trichlorinated compound, CB 28. Generally most of the considered species exhibited a similar behaviour, the sample and Florisil amounts had a positive effect on PCBs extractions and solvent volume and sulphate amount had a negative effect. The analytical determination and confirmation of PCBs were carried out by using GC-ECD and GC-MS/MS, respectively. The method was validated having satisfactory precision and accuracy with RSD values below 6% and recoveries between 81 and 116% for all congeners. The optimized method was applied to the extraction of real mussel samples from two Galician Rías.

      PubDate: 2016-11-19T08:58:47Z
      DOI: 10.1016/j.ancr.2016.11.003
       
  • Towards coupling dispersive liquid-liquid microextraction with hollow
           fibre liquid phase microextraction for extraction of organic pollutants of
           agricultural origin

    • Authors: Thabiso Letseka; Mosotho J. George
      Abstract: Publication date: Available online 9 November 2016
      Source:Analytical Chemistry Research
      Author(s): Thabiso Letseka, Mosotho J. George
      Liquid-based miniaturized techniques have received a lot of attention recently resulting in the development of the liquid phase microextraction (LPME) and dispersive liquid-liquid microextraction (DLLME) techniques each offering unique benefits over the other technique. Herein we report a combination of the two techniques for the extraction of hexestrol and atrazine from aqueous systems. The method sets off with the DLLME thereafter a hollow fibre filled with the organic solvent is introduced for the extraction of the pre-extracted analytes in the dispersed organic solvent. The method was modified further by introducing a second extracting solvent in place of the disperser solvent. Under the optimum conditions, namely, toluene in the acceptor phase, 1:1 chloroform:toluene (v/v) as a dispersed solvent, 15% NaCl, with the 15 min extraction time, the method achieved satisfactory enrichment factors (87- and 62-fold); sufficiently low detection limits of 0.018 μg/mL and 0.016 μg/mL using the flame ionization detector, while 0.072 and 0.063 ng/mL were obtained using single ion monitoring mass spectrometry detector, for atrazine and hexestrol, respectively; with sufficient linearity (R2 ≥ 0.9959). Although the compounds were not detected in the river water sample, satisfactory recoveries (111–115%) were achieved indicating the method did not suffer any negative matrix effect.
      Graphical abstract image

      PubDate: 2016-11-12T08:26:38Z
      DOI: 10.1016/j.ancr.2016.11.001
       
  • Double-functionalized magnetic nanoparticles for preconcentration and
           determination of polycyclic aromatic hydrocarbons in water samples

    • Authors: A.A. Al-rashdi
      Abstract: Publication date: Available online 27 October 2016
      Source:Analytical Chemistry Research
      Author(s): A.A. Al-rashdi
      A rapid and simple method for the separation and determination of five polycyclic aromatic hydrocarbons (PAHs) in water is described. The procedure is based on the selective extraction of the PAHs on the surface of modified magnetic nanoparticles using a solid-phase dispersion technique. The PAHs-loaded magnetic nanoparticles were separated from the aqueous phase with a magnet and then quantified by HPLC. The modified extraction method successfully replaced conventional extraction methods. The partitioning of the analyte between the sub-micron magnetic nanoparticles (solid phase) and the liquid phase occurs as the solid moves through the samples as a colloidal sol. The detection limits were in the range 0.14–0.31 ng/L, with recoveries ranging from 88% to 96%. The as-synthesized magnetic nanoparticles showed good stability and high extraction recoveries for the adsorption-desorption of PAHs, even after recycling four times. The procedure was successfully applied to PAHs determinations in real water samples.

      PubDate: 2016-10-28T22:09:27Z
      DOI: 10.1016/j.ancr.2016.10.003
       
  • Cloud point assisted dispersive ionic liquid –liquid microextraction for
           chromium speciation in human blood samples based on isopropyl
           2-[(isopropoxycarbothiolyl)disulfanyl] ethane thioate

    • Authors: Hamid Shirkhanloo; Mehri Ghazaghi; Mohammad Mehdi Eskandari
      Abstract: Publication date: Available online 15 October 2016
      Source:Analytical Chemistry Research
      Author(s): Hamid Shirkhanloo, Mehri Ghazaghi, Mohammad Mehdi Eskandari
      A efficient and fast method based on isopropyl 2-[(isopropoxycarbothiolyl)disulfanyl] ethane thioate (IICDET) were used for the speciation and determination of trace amount of Cr(III and VI) in human biological samples by cloud point assisted dispersive ionic liquid –liquid microextraction (CP-DILLME). Cr(VI) has carcinogenic effects, so, speciation of chromium in human body such as blood cells is very important. The cloudy solution was achieved by the mixture of acetone and IL ([C8MIM][PF6]) in human blood samples containing Cr(III) ions that were already complexed by IICDET at pH 4.5. After reduction Cr(VI) to Cr(III) by ascorbic acid, chromium speciation was obtained based on total chromium determination by electro thermal atomic absorption spectrometry (ET-AAS) and difference between total Cr and Cr(III) content. In addition, Cr speciation in human blood cells was calculated based on IICDET/CP-DILLME and hematocrit blood test (HCT). After optimized conditions, the enrichment factor (EF), Linear range and limit of detection (LOD) was obtained 25.2, 0.02–1.75 μg L−1 and 5.4 ng L−1 in human biological samples respectively. The validation of methodology was achieved by certified reference material (CRM) and ICP-MS technique.
      Graphical abstract image

      PubDate: 2016-10-16T13:00:30Z
      DOI: 10.1016/j.ancr.2016.10.002
       
  • Spectrophotometric determination of ammonia nitrogen in water by flow
           injection analysis based on NH3- o-phthalaldehyde -Na2SO3 reaction

    • Authors: Ying Liang; Chunmei Yan Qing Guo Jin Hongzhi
      Abstract: Publication date: Available online 11 October 2016
      Source:Analytical Chemistry Research
      Author(s): Ying Liang, Chunmei Yan, Qing Guo, Jin Xu, Hongzhi Hu
      The product of the NH3- o-phthalaldehyde (OPA) -Na2SO3 reaction is rose red at pH more than 10.4, and its maximum absorption wavelength is 550 nm. Based on this, a novel spectrophotometric method with flow injection analysis has been established to determine ammonia nitrogen in water. Experimental parameters related to the flow injection method and the reaction were optimized throughout the experiments based on univariate experimental design. The length of coil is optimized as 1.6 m for storing up standard or sample solution. The optimal value is 8.20 mL/min for loading flow rate of coloring solution. The OPA concentration, sulfite concentration and reaction pH are chosen as 1.06 g/L, 0.050 g/L and 10.80, respectively. The reaction temperature and stop flow time affects the performances of the method. The linearity range and detection limit of the proposed method are 0.100–0.700 mmol/L and 0.007 mmol/L at the reaction temperature of 55 °C and stop flow time of 340 s, respectively. The sample throughput is more than 8 h−1. Under the optimal experimental conditions, the recovery is 100.4%, 95.2%, 101.7% and 92.4% for the lake water, river water, groundwater and sewage, respectively. Two lake water samples were analyzed using both the proposed method and indophenol blue method, the results show no significant difference between these two methods. In comparison with other spectrophotometric determination method of ammonia nitrogen, the main merits of the proposed method are simplicity, reliability, reproducibility and high sample throughput.

      PubDate: 2016-10-15T12:58:44Z
       
 
 
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