Application of 4-(2-pyridylazo)resorcinol for flotation-spectrophotometric determination of iron

Abstract

ABSTRACT. Optimum conditions for flotation-spectrophotometric determination of iron with 4-(2-pyridylazo)resorcinol (PAR) based on a 1:2 Fe II -PAR complex were found to be as follows: flotation solvent (chloroform), shaking time (2 min), pH (4.50.5), concentration of PAR (2.0×10-4 mol L -1), reducing agent (hydroxylamine hydrochloride), solvent for the floated compound (dimethylsulphoxide, DMSO), wavelength for spectrophotometric measurements (718 nm), and volumes of the organic solvents (5 mL of chloroform and 3 mL of DMSO). Calibration graphs were compared for different volumes of the aqueous phase -10 mL and 40 mL; the corresponding linear ranges were 0.30-1.3 g mL -1 and 0.25-1.0 g mL -1. The iron content was successfully determined in soil samples, reference standard materials (PS-1, COOMET No. 0001-1999 BG, SОD No. 310а-98; PS-2, COOMET No. 0002-1999 BG, SOD No. 311а-98; and PS-3, COOMET No. 0003-1999 BG, SOD No. 312а-98) and zinc sulfide concentrates.

A novel samarium complex with interesting photoluminescence and semiconductive properties

“…3.91º, which is comparable with that previously documented [31,32]; For another, the two pyridyl rings have a larger dihedral angle of ca. 14.75º, comparable with that previously documented [33][34][35]. In the title complex, some weak π…π stacking interactions are established between the 4,4′-Hbipy moieties.…”