Reaction Model for Iron Dissolution Studied by Electrode Impedance: II . Determination of the Reaction Model

1981 ◽  
Vol 128 (2) ◽  
pp. 266-274 ◽  
Author(s):  
Michel Keddam ◽  
Oscar Rosa Mattos ◽  
Hisasi Takenouti
2006 ◽  
Vol 89 (1) ◽  
pp. 149-153 ◽  
Author(s):  
Ahmed H El-Ghorab ◽  
Kazutoshi Fujioka ◽  
Takayuki Shibamoto

Abstract A gas chromatographic method, along with a headspace solid-phase microextraction (HS-SPME), was developed for the determination of acrylamide formed in Maillard reaction model systems. The developed method was validated by liquid chromatography/mass spectrometry. A headspace sample was collected from an aqueous acrylamide solution (100 μg/mL) by SPME and directly injected into a gas chromatograph equipped with a nitrogen-phosphorus detector. The recovery of acrylamide from an aqueous solution was satisfactory, i.e, >93% under the conditions used. Acrylamide formed in an asparagine/d-glucose (molar ratio, 1/2) Maillard reaction model system heated at 150 and 170C for 20 min was collected and analyzed by the newly developed method using gas chromatography with nitrogen-phosphorus detection and HS-SPME. The amounts of acrylamide were 318 33 μg/g asparagine from a sample heated at 150C and 3329 176 g/g asparagine from a sample heated at 170C. Addition of cysteamine or glutathione to the above model system reduced acrylamide formation. Acrylamide formation was not observed when cysteamine or glutathione was added to asparagine in the above model systems to obtain equimolar concentrations of both compounds. This newly developed method is simple and sensitive, and requires no solvent extraction.


2016 ◽  
Vol 69 (3) ◽  
pp. 254 ◽  
Author(s):  
Marek Wojnicki ◽  
Ewa Rudnik ◽  
Magdalena Luty-Błocho ◽  
Robert P. Socha ◽  
Zbigniew Pędzich ◽  
...  

The kinetic studies of gold(iii) chloride complex ions recovery from acidic solution using activated carbon (AC) were carried out using spectrophotometry. AC samples were characterized in terms of surface area, porosity, and zeta potential. The surface functional groups were also identified. It was found that adsorption of AuCl4– onto AC was followed by reduction of the ions to the metallic form. The process obeyed the first order reaction model, but the reaction was controlled by diffusion. Arrhenius and Eyring–Polanyi equations were used for determination of the activation parameters. Distribution of gold across the AC pellets was also determined and discussed according to the porous material theory.


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