Design and characteristics of a mercury (II) optode based on immobilization of dithizone on a triacetylcellulose membrane

An optical sensor based on H-acid/layered double hydroxide composite film for the selective detection of mercury ion

“…Therefore, the H-acid/LDH film as a fluorescence chemosensor for Hg 2+ exhibits a broad linear response range and high selectivity. A comparison study between this work and other reported chemosensors of Hg 2+ [51][52][53] was performed (Table 1). It can be seen that the H-acid/LDH fluorescence sensor in this work displays a wide linear range response, but the detection limit is not as low as that of the sophisticated analytical techniques (cold vapor atomic absorption spectrometry (CVAAS) [54] and voltammetry [55]).…”

Optical pH sensor based on Calcon immobilization membrane

“…For this purpose, the transparent triacetylcellulose membrane was produced from waste photographic film that had been previously treated with commercial sodium hypochlorite in order to remove colored gelatinous layers [17]. This clean and dry membrane was placed in the solution containing 0.025 g Calcon (Merck), 0.04 g methyltrioctylammonium chloride (Merck) and 10 ml ethylenediamine (Merck) for 10 min at ambient temperature.…”

Membrane optode for mercury(II) determination in aqueous samples

“…The presence of extractant provides an increase in the selectivity and sensitivity of the optodes as compared to that obtained by solution spectrophotometry using same chromophore [7][8][9]. Most of the optodes reported in the literature for Hg(II) involve the use of optical fiber based optodes [10][11][12] or membrane based optodes [13][14][15][16][17][18][19][20]. Optical fiber optodes are based on the immobilization of indicators in the resins or beads, which are attached to the optical fiber tip for measuring the optical response produce by the optode [10][11][12].…”

“…In our previous work, the cellulose triacetate (CTA) has been used as a matrix forming polymer in the preparation of the optodes as they do not absorb water significantly and have good optical properties [8,9]. The different schemes used for the preparation of membrane optodes for Hg(II) are: (i) porphyrin-doped sol-gel films [13], (ii) plasticized PVC containing a lipophilic borate salt as an extractant for Hg(II) and the fluorescent oxacarbocyanine dye for its detection [14], (iii) 1-(2-pyridylazo)-2-naphthol (PAN) immobilized in PVC [15], (iv) fluorescence quenching of Hg 2+ -selective ionophore 5,10,15,20-tetraphenylporphyrin immobilized in PVC [16], (v) irreversible plasticized PVC optode incorporating the neutral ionophore along with lipophilic salt [18], (vi) dithizone immobilized on a triacetylcellulose film [17], (vii) 4-(2-pyridylazo)resorcinol (PAR) covalently attached to triacetylcellulose film [19] and (viii) trityl-picolinamide and a chromophore immobilized in the plasticized PVC [20]. The optode should be simple to prepare and capable of producing visual response in the form of distinct color change for Hg(II) ions within a short period of equilibration time.…”