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Affiliation(s)
- Teodora Scrob
- Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Cluj-Napoca, Romania
- Instrumentation and Chemometrics, Research Center for Advanced Chemical Analysis, Cluj-Napoca, Romania
| | - Anamaria Hosu
- Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Cluj-Napoca, Romania
- Instrumentation and Chemometrics, Research Center for Advanced Chemical Analysis, Cluj-Napoca, Romania
| | - Claudia Cimpoiu
- Faculty of Chemistry and Chemical Engineering, Babes-Bolyai University, Cluj-Napoca, Romania
- Instrumentation and Chemometrics, Research Center for Advanced Chemical Analysis, Cluj-Napoca, Romania
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3
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Hajmalek M, Goudarzi M, Ghaffari S, Attar H, Mazlaghan MG. Development and validation of a HPTLC method for analysis of Sunitinib malate. BRAZ J PHARM SCI 2016. [DOI: 10.1590/s1984-82502016000400003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Monireh Hajmalek
- Tofigh Daru Research and Engineering Company, Iran; Islamic Azad University, Iran
| | | | - Solmaz Ghaffari
- Tofigh Daru Research and Engineering Company, Iran; Islamic Azad University, Iran; Islamic Azad University, Iran
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4
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Peev D, Hofmann T, Kananizadeh N, Beeram S, Rodriguez E, Wimer S, Rodenhausen KB, Herzinger CM, Kasputis T, Pfaunmiller E, Nguyen A, Korlacki R, Pannier A, Li Y, Schubert E, Hage D, Schubert M. Anisotropic contrast optical microscope. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2016; 87:113701. [PMID: 27910407 DOI: 10.1063/1.4965878] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
An optical microscope is described that reveals contrast in the Mueller matrix images of a thin, transparent, or semi-transparent specimen located within an anisotropic object plane (anisotropic filter). The specimen changes the anisotropy of the filter and thereby produces contrast within the Mueller matrix images. Here we use an anisotropic filter composed of a semi-transparent, nanostructured thin film with sub-wavelength thickness placed within the object plane. The sample is illuminated as in common optical microscopy but the light is modulated in its polarization using combinations of linear polarizers and phase plate (compensator) to control and analyze the state of polarization. Direct generalized ellipsometry data analysis approaches permit extraction of fundamental Mueller matrix object plane images dispensing with the need of Fourier expansion methods. Generalized ellipsometry model approaches are used for quantitative image analyses. These images are obtained from sets of multiple images obtained under various polarizer, analyzer, and compensator settings. Up to 16 independent Mueller matrix images can be obtained, while our current setup is limited to 11 images normalized by the unpolarized intensity. We demonstrate the anisotropic contrast optical microscope by measuring lithographically defined micro-patterned anisotropic filters, and we quantify the adsorption of an organic self-assembled monolayer film onto the anisotropic filter. Comparison with an isotropic glass slide demonstrates the image enhancement obtained by our method over microscopy without the use of an anisotropic filter. In our current instrument, we estimate the limit of detection for organic volumetric mass within the object plane of ≈49 fg within ≈7 × 7 μm2 object surface area. Compared to a quartz crystal microbalance with dissipation instrumentation, where contemporary limits require a total load of ≈500 pg for detection, the instrumentation demonstrated here improves sensitivity to a total mass required for detection by 4 orders of magnitude. We detail the design and operation principles of the anisotropic contrast optical microscope, and we present further applications to the detection of nanoparticles, to novel approaches for imaging chromatography and to new contrast modalities for observations on living cells.
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Affiliation(s)
- D Peev
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - T Hofmann
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - N Kananizadeh
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - S Beeram
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - E Rodriguez
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - S Wimer
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | | | - C M Herzinger
- J. A. Woollam Co., Inc., Lincoln, Nebraska 68508-2243, USA
| | - T Kasputis
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA
| | | | - A Nguyen
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - R Korlacki
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - A Pannier
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - Y Li
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - E Schubert
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - D Hage
- Center for Nanohybrid Functional Materials, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
| | - M Schubert
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA
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7
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Li XJ, Xia ZC, Kong CH, Xu XH. Mobility and microbial activity of allelochemicals in soil. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:5072-5079. [PMID: 23647315 DOI: 10.1021/jf400949m] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The action of allelochemicals in soil needs their presence in the vicinity of the target plants. Using a soil TLC combined with bioassay approach, the mobility of 10 typical allelochemicals was evaluated. Ferulic, p-hydroxymandelic, p-hydroxybenzoic, and vanillic acids always had the lowest mobility (Rf < 0.1), whereas phenolic aldehyde and lactone (vanillin and coumarin) showed the highest mobility (Rf > 0.5). The Rf values of daidzein, 1α-angeloyloxycarotol, DIMBOA, and m-tyrosine ranged from 0.24 to 0.32. Binary mixtures of these allelochemicals led to an increase in mobility factors for selected combinations. Phospholipid fatty acid profiling indicated that there were different soil microbial communities in the segments containing allelochemicals residues in the developed TLC soil layer. A difference in microbial community structure occurred between two nitrogenous DIMBOA and m-tyrosine and another eight allelochemicals. The results suggest that the soil activity of allelochemicals on bioassay species and microbial communities depends on their mobility in soil.
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Affiliation(s)
- Xiao-Jing Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China
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Jim SR, Foroughi-Abari A, Krause KM, Li P, Kupsta M, Taschuk MT, Cadien KC, Brett MJ. Ultrathin-layer chromatography nanostructures modified by atomic layer deposition. J Chromatogr A 2013; 1299:118-25. [PMID: 23768654 DOI: 10.1016/j.chroma.2013.05.050] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Revised: 05/17/2013] [Accepted: 05/21/2013] [Indexed: 10/26/2022]
Abstract
Stationary phase morphology and surface chemistry dictate the properties of ultrathin-layer chromatography (UTLC) media and interactions with analytes in sample mixtures. In this paper, we combined two powerful thin film deposition techniques to create composite chromatography nanomaterials. Glancing angle deposition (GLAD) produces high surface area columnar microstructures with aligned macropores well-suited for UTLC. Atomic layer deposition (ALD) enables precise fabrication of conformal, nanometer-scale coatings that can tune surfaces of these UTLC films. We coated ∼5μm thick GLAD SiO2 UTLC media with <10nm thick ALD metal oxides (Al2O3, ZrO2, and ZnO) to decouple surface chemistry from the underlying GLAD scaffold microstructure. The effects of ALD coatings on GLAD UTLC media were investigated using transmission electron microscopy (TEM), gas adsorption porosimetry, and lipophilic dye separations. The results collectively show that the most significant changes occur over the first few nanometers of ALD coating. They further demonstrate independent control of film microstructure and surface characteristics. ALD coatings can enhance complex GLAD microstructures to engineer new composite nanomaterials potentially useful in analytical chromatography.
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Affiliation(s)
- S R Jim
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 2V4, Canada.
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Sherma J. Review of advances in the thin layer chromatography of pesticides: 2008-2010. JOURNAL OF ENVIRONMENTAL SCIENCE AND HEALTH. PART. B, PESTICIDES, FOOD CONTAMINANTS, AND AGRICULTURAL WASTES 2011; 46:557-568. [PMID: 21722083 DOI: 10.1080/03601234.2011.586589] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Techniques and applications of thin layer chromatography (planar chromatography) for the separation, detection, qualitative and quantitative determination, and preparative isolation of pesticides and their metabolites and other related compounds are reviewed for the period from November 1, 2008 to November 1, 2010. Analyses are described for a variety of samples types and pesticide classes. In addition to references on residue analysis, studies such as pesticide structure-retention relationships, identification and characterization of plant pesticides and synthesized pesticides, metabolism, degradation, mobility, identification of biomarkers for detection of herbicide effects in plants, and lipophilicity are covered.
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Affiliation(s)
- Joseph Sherma
- Department of Chemistry, Lafayette College, Easton, PA 18042-1782, USA.
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