Habibollah Khajehsharifi; Aida Solhjoo; Mohammad Mahdi Bordbar
Volume 3, Issue 2 , September 2016, , Pages 145-152
Abstract
A selective optical sensor based on immobilization of Eriochrome Cyanine R for the determination of Al(III) ions in aqueous solution has been developed. The method is based on the spectrophotometric measurement of complex Eriochrome Cyanine R-aluminium at 537 nm. The sensing membrane is made of a triacetylcellulose ...
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A selective optical sensor based on immobilization of Eriochrome Cyanine R for the determination of Al(III) ions in aqueous solution has been developed. The method is based on the spectrophotometric measurement of complex Eriochrome Cyanine R-aluminium at 537 nm. The sensing membrane is made of a triacetylcellulose film containing Eriochrome Cyanine R colorimetric reagent immobilized as an ion pair with methyltrioctylammonium chloride. The response of the sensor is based on the Eriochrome Cyanine R absorbance decrease by the coordination of Al(III) ions. At pH= 6.0, the linear dynamic rangeis varied from 3.22×10-8 to 4.10×10-5 mol L-1 with a detection limit of 1.2× 10-8 mol L-1. A dynamic working range, detection limit, sensitivity, selectivity and the response time were discussed in detail. The response was pH dependent. The membrane responds to Al(III) ions irreversibly by changing color from pink to blue. The membrane was regenerated in less than 30 seconds with 0.1 mol L-1 EDTA solution and was ready for further measurements. The response time of the sensor was within 16 min depending on the concentration of Al (III) ions. The sensor response was found to have a repeatability and reproducibility of 1.62% and 3%, respectively. The sensor provides appropriate selectivity to Al(III) ions over transition metal cations, including Co(II), Ni(II), Fe(III), Cu(II) and Zn(II). The sensor has been used for the determination of Al(III) ions in potable water and aluminium – magnesium syrup.
Ashraf Salmanipour; Sara Hooshmand
Volume 1, Issue 1 , March 2014, , Pages 1-6
Abstract
In this work, an optical sensor for detection of ascorbic acid is described. The sensor is fabricated by casting and spin-coating silica sol-gel doped with 2,6-dichlorophenol indophenol on the glass plates. The sols are in turn obtained by acidic hydrolysis of various precursors such as tetraethoxysilane, ...
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In this work, an optical sensor for detection of ascorbic acid is described. The sensor is fabricated by casting and spin-coating silica sol-gel doped with 2,6-dichlorophenol indophenol on the glass plates. The sols are in turn obtained by acidic hydrolysis of various precursors such as tetraethoxysilane, triethoxymethylsilane and triethoxyoctylsilane in the presence of 2,6-dichlorophenol indophenol as dopant. Prepared sols then were coated on glass plates to form sol-gel films. UV-Vis spectrophotometric properties of 2,6-dichlorophenol indophenol doped in sol-gel films were studied and compared with in solution. At the optimum conditions the response of film to ascorbic acid is fast and linear in 0.07 – 3.34 mmol L-1 range. Detection limit and relative standard deviation of presented sensor for determination ascorbic acid were 0.05 mmol L-1 and 1.32 %, respectively.