Detection and semiquantitative determination of cadmium and copper using polyurethane foam loaded with selective reagents

Fabrication of a Cu(II)-Selective Electrode in the Polyvinyl Chloride Matrix Utilizing Mechanochemically Synthesized Rhodamine 6g as an Ionophore

“…The semipermeability of PVC makes it perfect for this type of application. 36−40 A good number of copper-selective ionophores, derived from calixarenes, 41 porphyrins, 42 crown ether, 43 macrocyclic polyethers, 44 cyclic tetrapeptides, 45 thiophenes, 46 and so forth, were explored in the fabrication of ISEs for Cu(II). However, there are major bottlenecks with those reported ISEs such as higher LOD or serious interference from other cations such as Fe 3+ , Na + , Sr 2+ , Co 2+ , Ni 2+ , Cs + , Hg 2+ , Ag + , and K + .…”

Polyurethane foams in chemical analysis: sorption of various substances and its analytical applications

“…When these foams, as small cubes, are brought in contact with the solution under analysis, the white polymer acquires a colour typical of the given photometric reaction. These reactions are highly sensitive, for example, for sorption in the static regime, tenths (Co, 218 Cu, 214,218,233 Cd, 214 Pd, 233 Pb, 218,219 Cr, 230 Mo 234 ) and in some cases, even hundredths (Ag, 211 Ni, 205 Cu, 214 Zn, 218 PO 4 94 ) of a microgram of an impurity can be determined in a sample volume not exceeding 1 ± 2 ml. The sensitivity of determination increases by at least an order of magnitude when Co, 218 Cu, 218 Cd, 214 Cr 230 and Mo 234 are sorbed in the dynamic regime.…”

“…These reactions are highly sensitive, for example, for sorption in the static regime, tenths (Co, 218 Cu, 214,218,233 Cd, 214 Pd, 233 Pb, 218,219 Cr, 230 Mo 234 ) and in some cases, even hundredths (Ag, 211 Ni, 205 Cu, 214 Zn, 218 PO 4 94 ) of a microgram of an impurity can be determined in a sample volume not exceeding 1 ± 2 ml. The sensitivity of determination increases by at least an order of magnitude when Co, 218 Cu, 218 Cd, 214 Cr 230 and Mo 234 are sorbed in the dynamic regime. Detection of metals at a level of several nanograms in ml is attained by passing relatively large volumes of a solution (*1 litre) through a chromofoam filled column.…”

“…The use of these materials ensures higher sensitivity of analysis than the use of impregnated paper or than drop reactions. 205,214,218,219,230 Chromofoams are also suitable for a semiquantitative determination, which implies either comparison with standard colour scales after sorption in the static regime or measurement of the length of the coloured zone in the column after letting-through the solution under analysis. Usually, the colour intensity of chromofoams is linearly related to the metal concentration in the aqueous solution.…”

“…The second variant is associated with the techniques of thin layer spectrophotometry, which rationally combines the preconcentration of elements on PUF with direct determination of the absorption of light by the solid phase. 53,62,94,185,214,216,230 The essence of the method is in the sorption of coloured compounds by a PUF specimen shaped like a thin parallelepiped with dimensions corresponding to those of the cell (26160.1 cm), transfer of the sorbent into a cell filled with an organic solvent and measurement of the optical density. The solvent serves as an immersion liquid reducing light scattering.…”