Immobilization studies utilizing solid supports for the determination of fructose by dansylaminophenyl boronic acid (DAPB acid) and chromate by diphenylcarbazide (DPC)

Bulut, Mukadder
Immobilization of fluorescent chemosensors and chromogenic reagents on solid supports for developing optical sensors result in improved analytical performance characteristics such as continuous read-out, increased sensitivity, lower reagent consumption and possibility of using the sensor in solvents where the free molecule displays low solubility. The aim of this study is to immobilize dansylaminophenyl boronic acid (DAPB acid) and diphenylcarbazide (DPC) into various solid supports for the determination of fructose and hexavalent chromium, respectively. DAPB acid reacts with diol containing molecules to produce electron transfer resulting fluorescence quenching. Whereas DPC reacts specifically with chromate to produce a magenta colored complex having absorption maximum at 540 nm. Utilizing sol-gel technology, inorganic polymer matrices which enabled to observe fluorescence and absorbance signal in VIS region has been constructed. Also methylmethacrylate (MMA) and methacrylic acid (MAA), which are known to give transparent organic co-polymers, are chosen as monomers in the synthesis of organic copolymer. Hydrogels such as polyvinyl alcohol and Ca-alginate gel have been utilized for their good optical characteristics in the working range. Several considerations in the construction of host matrix were taken into account, such as the porosity of the polymers, functionalization of the matrix and use of additives for increasing the affinity of the medium toward the dopant molecule and swelling properties of organic polymers. The performances of the immobilizations were evaluated in terms of the transmittance and leaching properties of the host matrix, optical properties of dopant and optical response characteristic of the dopant for the analyte. The sensor applications of the immobilized probe molecule DPC were investigated. Studies regarding the enhancement of the performance of the flow injection analysis method for fructose determination, previously carried out in our laboratory, based on the fluorescence quenching of DAPB acid probe in solution were stated.


Melatonin induces opposite effects on order and dynamics of anionic DPPG model membranes
Sahin, Ipek; Severcan, Feride; Kazanci, Nadide (Elsevier BV, 2007-05-27)
The temperature and concentration induced effects of melatonin on anionic dipalmitoyl phosphatidylglycerol (DPPG) multilamellar liposomes (MLVs) were investigated by using Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). The results show that melatonin does not perturb the phase transition profile, while a decrease in the main transition temperature (T-m) is noticed at high melatonin concentrations (15, 24 and 30 mol Low concentrations of melatonin (3, 6 and 9 mol ...
Deposition of a Sorbent into a Recession on a Solid Support To Provide a New, Mechanically Robust Solid-Phase Microextraction Device
Poole, Justen J.; Grandy, Jonathan J.; Yu, Miao; Boyacı, Ezel; Gomez-Rios, German A.; Reyes-Garces, Nathaly; Bojko, Barbara; Heide, Harmen Vander; Pawliszyn, Janusz (American Chemical Society (ACS), 2017-08-01)
To date, solid-phase microextraction (SPME) fibers used for in vivo bioanalysis can be too fragile and flexible, which limits suitability for direct tissue sampling. As a result, these devices often require a sheathing needle to prepuncture robust sample matrixes and protect the extraction phase from mechanical damage. To address this limitation, a new SPME device is herein presented which incorporates an extraction phase recessed into the body of a solid needle. This device requires no additional support o...
New Generation of Solid-Phase Microextraction Coatings for Complementary Separation Approaches: A Step toward Comprehensive Metabolomics and Multiresidue Analyses in Complex Matrices
Gionfriddo, Emanuela; Boyacı, Ezel; Pawliszyn, Janusz (American Chemical Society (ACS), 2017-04-04)
In this work, a new generation of solid-phase microextraction (SPME) coatings based on polytetrafluoro-ethylene amorphous fluoroplastics (PTFE AF 2400) as a particle binder is presented. The developed coating was tested for thermal and solvent-assisted desorption, demonstrating its compatibility with both gas- and liquid-chromatographic platforms. The incorporation of hydrophilic-lipophilic balance (HLB) adsorptive particles provided optimal extraction coverage for analytes bearing a broad range of hydropho...
Spectroscopic intensities as measures of order parameter close to order-disorder transitions
Yurtseven, Hasan Hamit (Springer Science and Business Media LLC, 1988-01-01)
The infrared and Raman intensities can be related to the order parameter close to order-disorder phase transitions in crystal systems. In the present study this relationship has been obtained and compared with our experimental results for ammonium halides. Our predictions give satisfactory agreement with the observations in these crystals. It is proposed that the FTIR techniques can be appropriately used to evaluating the order parameter in various crystal systems.
Use of a simple transient extension chamber with ETV-ICPMS: quantitative analysis and matrix effects
Ertaş, Gülay (Royal Society of Chemistry (RSC), 2003-01-01)
The transient extension (TEx) chamber was developed to provide a simple means of lengthening an electrothermal vaporizer (ETV) signal for the purpose of obtaining a full mass scan from a single ETV firing with inductively coupled plasma mass spectrometry (ICPMS) detection. The TEx chamber was used for quantitative analysis of natural water (NIST SRM 1640). Quantitative analysis was done for Co, Be, Pb, Sb and Cd. Detection limits for the five elements tested with the TEx chamber were in the 1-10 mug L-1 ran...
Citation Formats
M. Bulut, “Immobilization studies utilizing solid supports for the determination of fructose by dansylaminophenyl boronic acid (DAPB acid) and chromate by diphenylcarbazide (DPC),” M.S. - Master of Science, Middle East Technical University, 2006.